Is Rambus Destined to Return? 202
An anonymous reader pointed us to an article running over at Tom's that talks
about the world
of ram and criticizes the performance of DDR. The article goes
into DDR333, DDR400, and Rambus, and explains the issues at higher
clockspeeds.
Experience tells us (Score:5, Funny)
Pocket books tell us that ddr is better.
Which will your wife let you decide on?
If I have to decide... (Score:2)
Re:Experience tells us (Score:3, Informative)
Re:Experience tells us (Score:1, Insightful)
But both CPUs will get much higher clock rates in the next few years, and it's not clear if DDR can keep up. If memory starts to seriously limit performance, then it will make sense to buy RDRAM. (Of course RDRAM + Athlon is not a possibility in the foreseeable future.)
Re:Experience tells us (Score:1)
Re:Experience tells us (Score:4, Informative)
The i850 chipset has a dual-channel RDRAM controller. It handles two channels of PC800 RDRAM, offering twice the memory bandwidth of PC1600, and about 25% greater than PC2100.
Conversely, the newer i845 DDR SDRAM memory controller offers single-channel support for PC2100.
If a dual-channel DDR motherboard was available for the P4, it would smoke the Rambus performance. Period. The article at Tom's stated that at the higher speeds DDR must have a relatively high CAS latency (2.5). This is still FAR lower than the latency in RDRAM. RDRAM is high-bandwidth, high latency. DDR is high-bandwidth, low latency.
I've been really disappointed with most articles at Tom's of late.
Re:Experience tells us (Score:1)
DDR is CHEAP, and it's GOOD. But of late it's been getting rather expensive, so the gap is closing. I was still running on PC100 when Crucial was selling 256MB PC2100 sticks for, what? $35? I assumed that prices would stay that way for a while, but when I finally decided to upgrade, the price rose to $60-70.
First Windows 98 (bought the original version four days before Second Edition came out), the Radeon (bought it two weeks before the GeForce3 and the newer Radeons came out), and now this, I really don't have any luck...I either seize the opportunity too early or too late. Doh!
Re:Experience tells us (Score:1)
You must have an awesome mastery of space/time, since there was a several-month time span between the release of the GeForce 3 and the Radeon 8500. If you truly were able to accomplish the same event exactly one time twice so that you did it two weeks before each event, you are truly a god among men.
Re:Experience tells us (Score:1)
Re:Experience tells us (Score:1)
Right, but the term "came out" generally implies "released", not "announced". Not that it matters. I was being facetious.
Seriously. (Score:2)
But to even entertain the thought in the first place, you can't be on an ultra-tight budget! So why try to save what will ultimately be a small % off the total price at the expense of performance?
It just doesn't make sense.
Though I still want to see a dual-channel DDR chipset for P4.
Rambus as a company (Score:2, Insightful)
Re:Rambus as a company (Score:2, Interesting)
Re:Rambus as a company (Score:2, Informative)
The memory benchmarks from above show that Pentium 4 really requires the 3,200 MB/s of data bandwidth supplied by the two Rambus channels. I doubt that it will perform as well with DDR-SDRAM, unless two channels will be used.
The business practices, of course, are a different story.
Re:Rambus as a company (Score:3, Insightful)
He links to an obsolete article from Q3 2000 about RDRAM on the Pentium III...
He talks about the "insanely high latency", and it's pretty obvious he's exaggerating slightly.
RDRAM's latency, particularly with the upcoming PC1066, is far better than people give it credit for. See this AcesHardware article [aceshardware.com].
PC1066 RDRAM latency for 128 bytes: 207 cycles
PC800 RDRAM latency for 128 bytes: 247 cycles
PC133 SDRAM latency for 128 bytes: 229 cycles
Slashdot moderators: Would it kill you to check the links before going points-crazy?
Re:Rambus as a company (Score:2)
Re:Rambus as a company (Score:2)
of a problem, esp. with how P4 is designed.
More factors than speed (Score:3, Interesting)
Other avenues for gaining speed exist- like Nvidia's extra memory controller for the gpu in the xbox and higher end nForce chipset.
Re:More factors than speed (Score:2, Interesting)
The dual 64bit memory controllers of the Nvidia nForce northbridge part allow the cpu and gpu to access the same ddr ram at the same time and with the same speed. This doesn't help in non 3d apps, but then I haven't seen a lot of desktop apps besides maya and games that are dying for a huge performance upgrade anyway.
Larrence Leisig and I agree that there is a lack of killer apps to drive the demand to drive the r&d to keep moore's law going. On the other hand there are vast areas of application for embedded systems. Scientific and other cpu hungry apps will continue to be parralelized and run on ever cheaper distributed systems.
common sense? (Score:2, Insightful)
It couldn't have just been the prices either, because Intel obviously knows they're not going to win that race.
Anyone?
Re:common sense? (Score:3, Insightful)
Intel had 2 reasons to bring out SDRAM based boxes:
1) Cost. Most consumers and business desktops don't care about speed, and RDRAM costs too much extra.
2) Speed. RDRAM looked fast because it was implemented with multiple banks. You can do the same thing with SDRAM, if you like. And that would give an apples to apples comparison.
Re:common sense? (Score:4, Insightful)
The whole advantage of RDRAM is high bandwidth/pin, and the fastest RDRAM has more than double bandwith/pin than the fastest DDR. RDRAM is very cheap to make dual channel because it has fewer pins. It is very expensive to make a dual channel DDR system because it requires that many more signals. The only dual channel DDR system I know of is the upcoming Serverworks Grand Champion chipset for the P4 Xeon which is very high-end (and no doubt expensive).
Re:common sense? (Score:2)
Actually, there have been multiple dual-bank SDRAM chipsets. While SDRAM and DDR do use more pins than RDRAM, that isn't necessarily a huge cost, especially since they're lower speed pins than RDRAM, which turned out (in practice) to be a pain in the neck.
Re:common sense? (Score:1)
Re:common sense? (Score:2)
However that has changed considerably. uBGA and similar achieve huge pin densities at tiny cost per pin. It is harder to get your process right with BGA - but once you only have to do this at the design/setup stage, once it's right you get better quality, repeatability and yield with uBGA than you do with Fine Pitch packages. Multilayer PCBs are much less of an issue too - as are fine pitches in those PCBs.
>The only dual channel DDR system I know of is the upcoming Serverworks Grand Champion chipset for the P4 Xeon
Intel and others are working on several Dual DDR chipsets - "Granite Bay" is supposed to be released Q3 this year.
Re:common sense? (Score:2)
I think the reasons were pretty clear:
1) RDRAM was extremely expensive compared with SDRAM
2) The performance advantages were (and are) largely theoretical in desktop PC's
3) DDR RAM in practice showed itself to be faster than RAMBUS.
4) The Athlon chipsets supporting SDR/DDR combined with the cheaper costs of the AMD CPU and DDR RAM gave AMD based machines a huge cost advantage to vendors who chose to go the AMD route
[In fact, i would've bought a Dell last year except they only had P4's with RDRAM. That made a Dell computer not only slower, but more expensive than the Micron PC with the Athlon that I eventually bought. The price difference was significant, too]
I hope not... (Score:5, Funny)
Sorry...
Re:I hope not... (Score:1)
Re:I hope not... (Score:1)
Wow, if I had mod points I wouldn't be sure whether to mod you up as funny or down as flamebait...
I've got a friend that would consider that accusation fighting words - he's been carrying Kurt's bubble gum card in his wallet for 15+ years and reveres him as a demigod.
Of course, I never watched him play a game (that I know of), and couldn't careless personally (I really hope that my firend doesn't read /. or he'll probably hunt me down).
What is the world coming to...
Re:I hope not... (Score:1)
As an small OEM computer maker, I hope not (Score:4, Informative)
Expensive + Has to run in pairs + Runs very hot == Useless to me.
Re:As an small OEM computer maker, I hope not (Score:3, Insightful)
Re:As an small OEM computer maker, I hope not (Score:5, Informative)
Interleaved memory designs (interleaving on a slot basis rather than interleaving on the RAM stick itself) causes many issues. First off, you have to have more slots for equivalent upgradeability. And more slots requires you to have more layers on the motherboard due to increased number of traces (although, admittedly, RDRAM has vastly fewer traces than SDRAM even so). It also requires more real estate on the board, which isn't debateable. Second, you start running into timing issues more often with interleaving than standard memory clocking. Sure, as you say, it depends how robust your controller is. But, funny thing, RDRAM either has amazingly shitty controllers, or they're just vastly more prone to lockups when you have slightly differing speed memory.
As for heat - it's not a tradeoff issue. DDR didn't double the heat of standard SDRAM, and RDRAM isn't merely twice as hot as DDR. It's absurdly hot. And heat is a major computer issue already between CPUs, chipsets, and graphics cards throwing off oodles of heat as is. I don't know of a manufacturer that has a fan blowing specifically over the RAM, but RDRAM could certainly benefit from this. Heat kills systems (more specifically, thermal changes kill systems, but you'll get faster thermal changes with hotter components), so why design a system with RDRAM that is so much hotter than the alternatives? For how little (if any) of a performance gain?
Oh, and you claim RDRAM is twice the speed. Ok. Want to compare apples to apples? Put RDRAM in a non-interleaved system (yes, they're out there. They're even predominant) and the memory bandwidth is only slightly higher than DDR. Or compare it to an interleaved DDR system (again, they're out there). Boom. You have a DDR system with nearly as much bandwidth as RDRAM.
And, frankly, bandwidth ain't all it's cracked up to be. Funny how DDR systems routinely spank RDRAM systems in real world benchmarks (not pure memory bench's). Why? Because latency is king. Particularly if you're multitasking. You'll hit different areas of memory so much that bandwidth will make little difference compared to latency. And RDRAM has really, really miserable latency. And it gets higher as you add more sticks. So while it's great for some things (video editing/streaming, etc), it sucks for most applications.
Re:As an small OEM computer maker, I hope not (Score:2)
Re:As an small OEM computer maker, I hope not (Score:2)
And as someone who build systems where reliability is a major issue - I am saying that heat is a damn good reason for disliking RDRAM.
If a component runs hot - that means it is using more power than a component which runs cool.
Fans create Noise
Fans are unreliable
Heat itself lowers reliability - a good "rule of thumb" is that every 10C rise in temperature halves the life of a component.
So Rambus = larger power supply, more cooling, more heat, more noise, less reliability.
Disclaimer - I am a bit biased - I mainly build systems which sit in racks in places like Telehouse, systems which are used for Telecomms therefore they must be seriously reliable. Heat and Fans matter more for me than they probably do for most desktop users. But the same basic principles still apply to everyone.
Re:As an small OEM computer maker, I hope not (Score:2)
Re:As an small OEM computer maker, I hope not (Score:2)
While that is a true statement, it is not true that it only depends on the memory controller, which makes the thrust of the statement false. If the variances between your RIMMS is such that it goes outside of the tolerances of the channel (which are measured in tens of picoseconds), there ain't shit your memory controller can do.
They run hot but have twice the memory bandwidth of PC2100 memory.
Unless you are only using one significant digit, that's just not true. Dual-channel PC800 RDRAM would provide 3.2GB/s theoretical, while single-channel PC2100 is 2.1GB/s. 3.2 is not twice 2.1... It's just over 50% more.
But even that doesn't really excuse running so hot. Dual-channel DDR (which has 25% more bandwidth than RDRAM, not that it helps the platforms that have it) isn't incredibly hot.
Though oddly in the end I have to agree with you... Interleaved and hot are kinda silly reasons to avoid rambus. Especially interleaved, because that only -helps- .
Re:As an small OEM computer maker, I hope not (Score:2)
Re:As an small OEM computer maker, I hope not (Score:2)
Covering Research Costs (Score:2)
This can be a problem. You should be able to make back the money so you cover your costs. Unfortunately, you may have to have deep pockets to stay in the game for a long time.
not that profound of an article (Score:1)
It's not news that a CPU which was designed to use one memory doesn't perform as well when using a different kind of memory. The PIV needs memory bandwidth desperately. How was Intel supposed to know that all those Alpha engineers would go to AMD and give the public a decent alternative? How were they to know that the public would have the option of getting better performance for less than half the money? The PIV is the last processor of an era AMD just put an end to. It's foolhardy to derive the future of a memory technology from its performance in conjunction with a misdesigned processor. If you could test an Athlon with DDR versus RDRAM, of course, the DDR would perform better. Please let's not post "news" from Tom's anymore - Tom's has just really gone to crap.
We'll give 'em the niche market. (Score:1)
When price isn't an issue, and politics not a motivater, it's amazing what ends up in the niche.
-Slashot is like a sewer, what you get out of it, pretty much depends on what you put into it.. - Updated Tom Lehr.
Test costs remain high, apps support remains nil (Score:5, Interesting)
If you also figure that the memory controllers for Rambus are configured for dual-channel operation, it becomes much clearer that the advantage is not in the memory architecture itself but in the controllers. Suppose a server board manufacturer decides to support quad-channel PC2700 1GBx4. That's 10.8 GB/s of potential memory bandwith on sequential accesses! There's hope with chipsets like the Nvidia nForce420 dual-channel DDR, but the Athlon FSB is the limiting factor there. And let's not get into the infamous first-access latency issues which I hope they're finally addressing.
Rambus is also notorious for poor tech support. I worked for a major silicon vendor using their core, and they never responded to our requests for minimum PLL-to-Rambus core distances. It was abjectly ridiculous, but not surprising considering that regular SDR/DDR memory interfaces outnumbered Rambus designs 100:1. Have things changed? Considering what their legal bills have been lately and an erosion of their tech support, I doubt they can afford to improve it much.
Re:Test costs remain high, apps support remains ni (Score:2)
Intel uses testers from schlumberger [slb.com] (their reps are quick to point that out). Typically, a tester cost anywhere from 1-10 million dollars + plus they require a lot of maintenance, calibration, etc. Basically, the faster and more pins you need, the more it cost.
I've worked with some schlumbeger 'KX' testers, they're a big pain in the ass, unreliable, and are badly designed: just shutting the thing off can break it!! (especially if you use the emergency off button).
There is another choice, however, you can use 'bist'(built-in self test) and have the chip basically test itself :-). This allows companies to get away with using cheaper, more reliable testers.
Re:I know of no company doing analog BIST right no (Score:1)
doesn't it depend... (Score:4, Insightful)
and until there is a rambus/athlon chipset i don't really think we can gague the real world implication of it...
either way i have better things to do with a few $100 than put it into a more expensive chipset/cpu/memory rig. if you have the extra money and the rambus system gives you what you want, then more power to you. overall, right now, you can't say either system is "the best" in ever possible catagory
Re:doesn't it depend... (Score:2)
Re:doesn't it depend... (Score:2)
the new p4 is going to be 133x4=600
dual ddr, assuming it's 333, would be 166x2x2=666
assuming each channel is the same width (i can't remember right now) would that extra 66mhz.x64bit make that much of a difference? might be intresting for overclocking though... according to Ace's [aceshardware.com] the NForce has really good overcloackability. i wonder if it's cause of the eaxtra memory bandwidth headroom...
Re:doesn't it depend... (Score:2)
I think the Grand Champion HE has four channels, so you'd get 6.4GB/s; that's probably only useful for workloads with a lot of DMA traffic (e.g. disk and network I/O).
Problems with RDRAM (Score:1)
The first one is the price. It's simply more expensive than DDR Ram as far as I can see.
Secondly, it appears to me that we are getting to the spliting hairs, angels dancing on a needle level here with RAM. Unless it dramaticly increases my boot time, time to do things in a word processor, makes mySQL fly like a greased dolphin, gives me kickass FPS in UT, or makes my G4 fill my bowl with Fruit Loops in the morning, I'm not going to spend one cent more for RAM than I have to.
If RDRAM is 101 dollars for 256 and DDR is 100 dollars for 256, I'm going to go with the DDR and the hardware that supports it.
Re:Problems with RDRAM (Score:2)
But if what you get with DDR is "good enough", then of course you should go with that, because it is cheaper.
Re:Problems with RDRAM (Score:1)
Re:Problems with RDRAM (Score:2)
Re:Problems with RDRAM (Score:1)
This Topic Sucks... (Score:1, Funny)
My time with rambus has been awesome (Score:3, Interesting)
I gotta say, this stuff is hot, my friends have all gone off and bought gforce3's, amd's with DDR. I thought these new cards/systems would have score winmarks well above my own (around 3800 with a gforce2gts) but I was surprised to see they only score 1000 or so more than me.
Out of curiosity, we put one of those GF3's in my system. Without fail I would score about 400 to come in around 6300 3dmarks above my buddies amd1.6. My P4 is just 1.4. Yet even with a lower clockrate the memory bandwidth made a huge difference.
I'm not trying to cause a ruckus here, anyone with deep enough pockets (or access to enough systems) can just as easily do the same testing I did. Bottom line whether or not the moderators like it is rambus systems do provide the absolute best possible performance in 3D gaming. It certainly was expensive when it came out but now with the falling prices of all ram, it's within reach of anyone that want's that extra "oomph" in thier system.
Does anyone know of any AMD boards that use rambus? I'm sorta curious what kind of scores those get in comparison to the intel one's. Anyways thats my comment.
Re:My time with rambus has been awesome (Score:4, Insightful)
What about games that -don't- love the P4, like, say, -any other game- (even those based on the Q3 engine)?
But no one needs to do the same testing you did. They can just look at all the tech sites. Hey, you already visited Tom's Hardware to read this article, check out who -he- thinks has the "best possible performance in 3D".
At one time, your "best possible performance in 3D gameing" applied... That time was the year 2000, and Q3A was the most demanding benchmark anyone could cook up It is now 2002, and the world has moved on from Q3A, and P4 lost that crown. But nice try.
You should have said "media encoding", because then you'd have been right even today.
As to AMD using Rambus... It'd suck. P4 does better with RDRAM than DDR because it's a highly pipelined, high-clocked machine that craves bandwidth. The K7 is a very wide machine, and for it the worst thing that can happen is having to stall waiting for data. The latency of RDRAM would kill the K7. You'll note that the dual-channel nforce (higher theoretical bandwidth than the i850, and 2x the KT266A) doesn't outperform VIA's chipset. An likely reason would be that the KT266A has lower latency, and that more than makes up for the extra bandwidth (which K7 doesn't need).
Re:My time with rambus has been awesome (Score:2)
Go read the hardware sites. Quake3 does ABSURDLY well on a P4 for some reason. Nobody can explain why. Jon Carmack doesn't even understand why last I read. But because of this, it's not a wonderful benchmark for AMD vs P4 comparisons. If it's all you play, then that's fine - benchmark it off that. Otherwise go look at other gaming benchmarks, like Serious Sam and Anandtech's new Unreal2 benchmark (which is of debatable value, admittedly).
Of course, then you might realize that people who have a clue are right, and that RDRAM costs 2-4x as much as DDR for no performance gain. Or for a performance loss in some cases.
And no, AMD doesn't use RDRAM. Nobody's even bothered to even design an AMD motherboard that uses Rambus. Partly because it makes no sense - AMD is still mostly used by people who are cost conscious, and RDRAM isn't desired in that catagory. Partly because it would be relatively difficult to design such a beast, due to lack of support from AMD. And partly because there's no performance advantage in the real world.
Oh... and even in Q3... consider how much more you spent for RDRAM, a P4, and the premium on the motherboard as compared to a comparable Athlon system. Then figure that out as a percentage of system cost. Then figure out how much performance percentage you gained. I bet the first is greater than the latter.
Rambus? Naw (Score:1)
What I got out of it was.. (Score:1)
This is the 'return of Rambus!'?
Please. SDRAM is the standard. DDR is entrenching into that market. Rambus? It's like the Mac - some people wonder, 'What's that?' while the techs laugh at people who have it.
Rambus is a horrible. The technology? No, the company. Not by speed, but for business should we continue ignoring it. They are a horrible company, and despite their products, should not be dealt with as a result.
The technology.. Isn't really any better or worse than SDRAM/DDR save for price. I've seen boxes refuse to boot when two different brand yet same speed/size SDRAM chips were inserted into a computer. I've seen bits 'o SDRAM cause page faults, kernel panics, etc.
I've seen Rambus do the same. *shrug*
Re:What I got out of it was.. (Score:2)
Maybe. But, often it's the non-techs that make technical decisions, at least in a business environment. I'm sure companies like Dell are selling plenty of systems with RAMBUS in it.
Having a technologically superior product does not mean you'll succeed commercially. Having an inferior product does not mean you'll fail. Unfortunately.
Tom, as usual, not 100% (Score:5, Informative)
But he does misrepresent some issues. For example, signal integrity issues. I can say with complete assurance that Rambus is loaded with signal integrity issues. These issues get -very bad- as the clock frequency goes up. Also Rambus is -not-, strictly speaking, a serial bus. First, it is 16 bits wide, while pure serial would be 1. Second, the depiction of a DIMM as being a unterminated stub with significant SI issues is correct, but this doesn't go away with rambus, and this definition of "serial" fails as well. While the signals do pass through a RIMM continuously, eliminating the RIMM itself as the source of major SI problems, you still have each and every RDRAM device itself acting as an unterminated stub, each of which causes reflections of its own. Especially for devices with tolerances as low as RDRAM, this can be difficult to manage. While in the balance I'd have to concede that at a given clock frequency RDRAM has the SI advantage, remember that RDRAM needs 4x the clock frequency of DDR to match bandwidth.
Or you could have 2 channels of rambus, and only need 2x the frequency. Well, 2 channel DDR is becoming a reality. Not only does nForce support it, Sledgehammer will as well. Neither of these are Intel platforms, but I would guess that going dual-channel would be a natural step for VIA and others competing with Intel chipsets. It would especially make sense for p4, as it would more than make up the memory bandwidth disparity that currently exists.
Speaking of nForce, another thing I take issue with is the suggestion that the nforce's DIMM-slot population problems are indicative that DDR is crippled by SI issues. I think more likely is that this was the first chipset designed by a company whose experience lies solely with graphics cards, on which the ram is directly soddered to the PCB. Lack of experience in the harsher SI conditions of a computer motherboard are to blame.
Speaking of DIMM population, it's hard for me to see only having 2 DIMM's on some boards as a particularly black mark for DDR... That leaves you with 2GB per channel, the same as RAMBUS.
So, he was right about some things, insightful on others, but the picture is -not- so clear-cut in the image of rambus Inc.
Re:Tom, as usual, not 100% (Score:4, Insightful)
Re:Tom, as usual, not 100% (Score:2)
Which is pretty damn bad!
Serial != 1 bit. Serial == takes more than one clock cycle to transfer a word.
Oh, shit. Well, a word in x86 land is 16 bits, so I'm in the clear, right? I mean, all the macros for 32-bit integers are all "DWORD", right?
Re:Tom, as usual, not 100% (Score:4, Informative)
Re:Tom, as usual, not 100% (Score:2)
QDR. . . . (Score:2)
Not to mention how far up Nvidia has managed to scale DDR RAM. Heh. I would like to see RAMBUS get that.
RAMBUS would settle down good in a video toaster type of applicance, but that is about it. Video editing seems to be one of its few strong suits.
Besides, I would like to see a Motherboard that is halfway cheap and can support 3-4GigaBytes of RAMBUS RAM.
Re:QDR. . . . (Score:2)
At least it doesn't have the associations with East Germany.
Cost control (Score:5, Interesting)
The days of cheap memory are over.
They say this because of the huge expense needed to provide 512MB or more of ultra fast memory. But what if they added yet another level of "cache"?
Put in 128MB or more of super-fast RAM (faster than today's RDRAM or DDRAM, maybe using an exotic bus) backed by gigs of cheap, easy-to-make memory (PC266 DDRAM or slower). The cheap ram is still orders of magnitude faster than a disk drive. Manage them with hardware that does page swapping similar to virtual memory.
You could get good system performance and lower overall cost.
Re:Cost control (Score:2)
Intel's McKinley chip reportedly has 3MB of Level 3 on-chip cache. Not exactly what you are proposing, but the same basic principle.
Slightly off-topic: there's an interesting column in Embedded Systems magazine where the author expresses concern about cosmic rays flipping bits in this cache. Apparently Intel acknowledges that this may be a problem (they have studied it). Intel claims a 'normal' user should experience this problem once every 1000 years. However, as the author points out, what if every airplane is equipped with a McKinley chip? Apparently there are 7000 planes in the air at any given moment (on average), so would that mean 7 plane crashes a year due to this problem?
To get on topic again: your idea is interesting, but maybe we should try to avoid running monstrous applications that need ridiculous amounts of RAM.
Having said that, I did run into a memory problem when I had to edit a 270MB text file the other day. For some reason, the 512 MB of memory in my machine wasn't enough. Emacs wouldn't load the darn file ("buffer size exceeded"), and Wordpad hung. I tried Notepad (I know, I'm nuts...), and it actually worked! The machine started thrashing like crazy, it took several minutes to scroll, but eventually I managed to do the minor edits. Yes, Linux probably would have done it without a problem, but that was just not an option, so save me your flames. And I hate vi, so don't bother...
Rambus (Score:1)
But really Rambus is not the solution, but another technology will finally arrive. Damn it, I want those quantuam computers with 3D optical storage!
How much does Tom get kick-backs for supporting Rambu$? They are one of poster boys for Patent reform for both consumers and the patent holders.
DDR doesn't slow P4, it;s pipeline does (Score:1)
The one thing it's good at, it doesn't get to do...
Is Intel's DDR implementation bad, or not? (Score:4, Insightful)
Then the political aspect is ignored and he talks almost exclusively about technical issues about why Rambus might theoretically be better, and uses existing intel chipsets as evidence.
Hello? Answer the question, please? Has Intel ever come out with a non-crippled DDR chipset for the P4? How do Intel's DDR P4 chipsets compare to non-intel DDR P4 chipsets? (ARE there any non-intel P4 chipsets?)
How much of the problem is political, and how much of it is a real technical issue?
Re:Is Intel's DDR implementation bad, or not? (Score:1)
Re:Is Intel's DDR implementation bad, or not? (Score:2)
Show some backbone (Score:2)
Don't get me wrong, THG rocks and I respect Tom's advice. He knows 10x more than me about hardware. But he should explain why this review is so opposed to the ones he wrote himself...
Quantity vs Quality (Score:3, Insightful)
They have $93 for 512mb SDRAM and $175-250 for 512mb RDRAM.
My question is this: Let's say I have a choice between 512mb of SDRAM and 256mb of RDRAM. Would the SDRAM not almost always be faster because RAM, however slow, trumps swap space every time?
In other words, isn't the amount of memory I have more important than how fast it is?
Many moons ago, I had a SGI O2 workstation. Tremendous memory bandwidth, but memory that cost 10x more than anything else. As a result, it could be embarassed by lesser machines, since I couldn't afford to load it up with RAM.
I see Intel repeating the same mistake when it decided to focus on RDRAM.
Apple is putting L3 cache in their G4s so that the use of expensive RAM is confined to a relatively small and affordable amount. I can upgrade my PC133-equipped G4/450 dual processor to the latest 1ghz dual processor, put my 1.5gb RAM in it, and fly. That seems like a good compromise to me, maybe better than going to DDR, which I would have to buy new.
Thoughts?
D
Re:Quantity vs Quality (Score:2, Insightful)
They have $93 for 512mb SDRAM and $175-250 for 512mb RDRAM.
Tom's price guide is not usually the place to find the lowest prices on hardware. But it's also not entirely fair to compare RDRAM prices with normal SDRAM prices, because of the performance difference and shrinking platform availability for non-DDR SDRAM.
If you look at pricewatch.com, though we can find some prices like these:
Samsung 512MB RIMM for $156 + $9 shipping from some provider called 11cb. I simply picked this as the cheapest Samsung-labeled provider, since Samsung provides some of the best RDRAM. Keep in mind for interleaved operation that you'll actually be using two RIMMs, so you might instead want to compare 2x256MB or simply look at 2x512MB for your other RAM platforms.
From SDRAM and DDR SDRAM I'll just pick Crucial/Micron, while they won't be picked as the high-performance provider (people would be more apt to pick Mushkin or Corsair for performance) you'll see much less flakiness than with a non-labeled generic provider.
(Shipping not mentioned with Crucial, check their site)
Micron 512MB PC133 CL2.5 $139 + $10 shipping from "Alpha International Business Inc."
Crucial 512MB PC133 CL3 $139 Crucial 512MB PC2100 CL2.5 $152
Now for the faster DDR I'll pick the lowest reputable name-brand item, since Micron/Crucial don't offer all speeds of DDR, currently.
Corsair 512MB PC2400 CL2 $187 + $9.74 shipping from Googlegear.com
Mushkin 512MB PC2700 CL2.5 $211 + $9 shipping from Mushkin
Now, I don't intend for you to read too much into this, but provided you stay with "non-crap" providers of memory, the closer you come to the performance levels of RDRAM, the less you see a price difference in favor of SDRAM.
My question is this: Let's say I have a choice between 512mb of SDRAM and 256mb of RDRAM. Would the SDRAM not almost always be faster because RAM, however slow, trumps swap space every time?
In other words, isn't the amount of memory I have more important than how fast it is?
If you aren't being limited by the amount of system memory, then no. Provided that for your application at hand you don't need more memory than you currently have available, swap access differences really aren't an issue. Does it matter that you have 1GB of memory if you only use a small portion of it for something other than disk cache, when compared to 512MB of memory with much more bandwidth?
If you don't need or can't use the bandwidth, then of course it's not overly useful. Or if you need to access more data than you can realistically ever store in memory, then there will be a point where memory bandwidth is made mood by increased disk access. It's a matter of application and necessity of your processor.
The Pentium 4 sees very realistic gains from using RDRAM versus DDR memory, because of how it was designed.
At one point Intel was being embarrassed by the absurd cost of RDRAM, but times have changed. It's continued to go down in price, and DDR and normal SDRAM have recently increased in price.
Re:Quantity vs Quality (Score:2)
No. If your software's working set is smaller than the amount of physical memory, you are better off with the faster memory. You can create software workloads that make either configuration look better.
Re:Quantity vs Quality -- RAMBUS now affordable (Score:2)
I think this is probably true.
However, as you point out, the price difference between RAMBUS and SDRAM is now very small. According to Sharky Extreme [sharkyextreme.com] the difference between 512 MB of SDRAM and RDRAM is about $80, and DDR RAM (PC2100) is actually more expensive than RDRAM! So if you plan to put 2GB in your machine, SDRAM is appreciably cheaper, but if you plan to do that, you probably plan on some serious hardware as well, so you'll probably spend $3000+ (probably coulnd't get a motherboard that would take 2GB SDRAM anyway...).
My point is that both SDRAM, DDR RAM and RDRAM have come down in price dramatically in the past year (although memory prices seem to be on the rise again). The price difference is very small when compared to the total price of the machine, so why bother? I have nothing against DDR RAM, but it'll have to win on technical merit nowadays.
As an example, I had to specify and buy a PC for my job some weeks ago. Now, this PC will be running a very specialized application, and nothing else. No CD burning, MPEG/MP3 encoding, no image processing, and no games. I like a cool machine as much as the next guy, but I simply could not justify putting more than 512 MB in this machine. Same for the hard drive, 40GB should be more than enough. A decent monitor was a requirement however. So why save $80 on memory when we're spending $700+ on the monitor alone?
Summarizing: if 512 MB is enough for you, why bother? If it isn't enough, you'll likely spend a lot of dough anyway, so again, why bother?
Why does everyone hate rambus? (Score:1)
Re:Why does everyone hate rambus? (Score:3, Insightful)
Intel and Rambus were hoping to strangle the market into adopting RDRAM in order to hurt Intel's competitors, and when this failed (RDRAM's prices lead people to adopt PC133 and then DDR), they attempted to obtain royalties or sue developers of alternative memory technologies for patent infringement of one form or another.
sheep, ignorance, patents... (Score:2)
Re:Why does everyone hate rambus? (Score:2)
Fortunately, in May 2001 a Virginia jury convicted rambus of fraud.
Unfortunately, they fine the jury imposed on Rambus ($3.5m) was reduced to a mere fraction of the original penalty ($350,000) by state laws capping the limit of punitive damages.
A mere slap on the wrist for a company which acted so unethically.
Highly Doubtful (Score:3)
Tom contradicts himself? (Score:1, Informative)
Tom's Credibility (Score:1, Interesting)
The highest performing chips ever use rambus (Score:1)
Alpha EV7 with it's RAMBUS controller ON CHIP.
Just because PC architecture is limited by chipsets with limited memory bus bandwidth does not mean there are no other uses for such a memory architecture.
Peter
RAM in Laptops (Score:2)
There will NEVER be a laptop with RIMMS in them because they are too damn hot. Unless the design of them drastically changes in some unknown way, this "NEVER" is a fact.
I think there are some DDR laptop solutions in the pipe now. Yet, there is the problem of the slower system bus speeds on laptops, so it will not matter much until that's fixed too.
Re:toms [OT] (Score:1)
Re:toms (Score:1)
Probably because we all argue and yell at tom and each other. discussion is good...then again, any article comparing any two products is heavily debated, from distro's to text editors. I guess tom must be special.
How about this FUD: (Score:1)
Re:I refuse to believe tomshardware.com anymore (Score:3, Interesting)
There was a rumor being spread by some kids with AMD processors that the Pentium 4 runs at half speed whenever you do more than just checking email with your computer. They had taken a new feature in the Intel processor and manipulated it into a fault. Tom's article was only trying to explain what the feature is and why it's good, since many people did not understand what it was about. He was not in any way saying that your heatsinks are going to fall off and your processor will burn up, if you use an Athlon processor. It was not an attack on AMD, it was just an explaination of a new feature found in certain other processors.
Re:I refuse to believe tomshardware.com anymore (Score:2)
Re:I refuse to believe tomshardware.com anymore (Score:5, Insightful)
It's true. If the heatsink falls off your Athlon it is toast. (note that just in the last week or so a board was released that supported the XP's thermal diode... but for all other boards/chips, you still get toast)
Tom isn't the genius a lot of people think he is (or that he'd want you to think), but that was not FUD.
Re:I refuse to believe tomshardware.com anymore (Score:1)
Not that Tom and Tom's Hardware aren't a nVidia/AMD owned FUD machine with less brains that a small primate... Not passing a -j n to build kernels on a SMP AMD machine = stupid, showing your monitor refresh rate for LAME encoding = stupid, selecting items as "winners" that perform in the middle or toward the bottom of your own benchmarks = stupid,
Re:I refuse to believe tomshardware.com anymore (Score:2)
If he doesn't want to look like a dipshit, he shouldn't put dipshits on the payroll.
Re:I refuse to believe tomshardware.com anymore (Score:2, Insightful)
Ouch, troll, and he's wrong too! (Score:1)
Been reading too much Tom's Hardware Misinformation Guide?
Re:DDR Rules! (Score:1)