Corsair and OCZ: New Standards in Fast DDR2
by Wesley Fink on August 4, 2006 5:50 AM EST- Posted in
- Memory
Corsair CM2X1024-6400C3: Memory Performance
Most top Intel motherboards provide a wide range of memory ratios that match available DDR2 memory. Most end-users select the memory ratio that matches their DDR2 memory speed. For those reasons, we first test all of the stock ratios at the fastest stable timings we can achieve at the given ratio. With ratios, CPU speed remains the same at 2.93GHz in our memory test bed, and memory speed is then changed by selecting different ratios.
There are some downsides to this approach. With the memory controller in the chipset, instead of part of the processor as in AM2 systems, there is a small performance penalty for speeds other than a 1:1 ratio (DDR2-533 in this case). However the penalty is in reality very small and memory scales nicely through the various speed options.
The performance of Micron DDR2 memory chips was already impressive in the high-performance DDR2 in the Conroe Buyers Guide, but Corsair takes the DDR2 performance standard even higher with their 6400C3. This memory is clearly the best of the best, allowing 3-2-2 timings to DDR2-533, 3-2-3 at DDR2-667, 3-3-3 at DDR2-800, and an astounding 4-3-4-11 at DDR2-1067. The base chips are from the same manufacturing lines, but Corsair binning and custom SPD programming have squeezed even more from these excellent memory chips. The only real concern, of course, is the very high cost, but that will not likely matter much if the absolute top performance is your system goal.
The fastest possible timings with today's DDR2 are 3-2-2. If you look closely you will see the Corsair 6400C3 works fine at the fastest timings that can be selected at both DDR2-400 and the 1:1 ratio of DDR2-533. Even at DDR2-667 only minor compromises are required, since the Corsair is completely stable at 3-2-3 timings. It is important to keep in mind that the first 5 table rows, from DDR2-400 to DDR2-1067 represent a constant CPU speed of 2.93GHz with memory running at faster speeds through ratios. Any performance increases over this DDR2-400 to DDR2-1067 range is therefore a result of increased memory speed. 1:1 should always have the least overhead in the current Intel universe, but this DDR2 memory still scales well by speed over the full range. Memory bandwidth improves with memory speed, as does raw calculation performance. However, this does not always translate into linear gaming performance. You can see this more clearly in the new performance scaling charts on page 7.
Corsair 6400C3 topped out at DDR2-1112, which is the second highest stable speed ever achieved with our DDR2 memory samples. This is particularly interesting when you consider that this Corsair memory, rated at DDR2-800, actually reaches a slightly higher top speed than we could achieve with Corsair DDR2-1067. Corsair clearly binned this memory for tight timings across the band and at a lower than average voltage in this class range. The 6400C3 achieves that design goal, and always does so with tighter timings than we would expect.
Most top Intel motherboards provide a wide range of memory ratios that match available DDR2 memory. Most end-users select the memory ratio that matches their DDR2 memory speed. For those reasons, we first test all of the stock ratios at the fastest stable timings we can achieve at the given ratio. With ratios, CPU speed remains the same at 2.93GHz in our memory test bed, and memory speed is then changed by selecting different ratios.
There are some downsides to this approach. With the memory controller in the chipset, instead of part of the processor as in AM2 systems, there is a small performance penalty for speeds other than a 1:1 ratio (DDR2-533 in this case). However the penalty is in reality very small and memory scales nicely through the various speed options.
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| Click to enlarge |
The performance of Micron DDR2 memory chips was already impressive in the high-performance DDR2 in the Conroe Buyers Guide, but Corsair takes the DDR2 performance standard even higher with their 6400C3. This memory is clearly the best of the best, allowing 3-2-2 timings to DDR2-533, 3-2-3 at DDR2-667, 3-3-3 at DDR2-800, and an astounding 4-3-4-11 at DDR2-1067. The base chips are from the same manufacturing lines, but Corsair binning and custom SPD programming have squeezed even more from these excellent memory chips. The only real concern, of course, is the very high cost, but that will not likely matter much if the absolute top performance is your system goal.
The fastest possible timings with today's DDR2 are 3-2-2. If you look closely you will see the Corsair 6400C3 works fine at the fastest timings that can be selected at both DDR2-400 and the 1:1 ratio of DDR2-533. Even at DDR2-667 only minor compromises are required, since the Corsair is completely stable at 3-2-3 timings. It is important to keep in mind that the first 5 table rows, from DDR2-400 to DDR2-1067 represent a constant CPU speed of 2.93GHz with memory running at faster speeds through ratios. Any performance increases over this DDR2-400 to DDR2-1067 range is therefore a result of increased memory speed. 1:1 should always have the least overhead in the current Intel universe, but this DDR2 memory still scales well by speed over the full range. Memory bandwidth improves with memory speed, as does raw calculation performance. However, this does not always translate into linear gaming performance. You can see this more clearly in the new performance scaling charts on page 7.
Corsair 6400C3 topped out at DDR2-1112, which is the second highest stable speed ever achieved with our DDR2 memory samples. This is particularly interesting when you consider that this Corsair memory, rated at DDR2-800, actually reaches a slightly higher top speed than we could achieve with Corsair DDR2-1067. Corsair clearly binned this memory for tight timings across the band and at a lower than average voltage in this class range. The 6400C3 achieves that design goal, and always does so with tighter timings than we would expect.
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Beaner - Friday, August 4, 2006 - link
Just curious...The picture of the Corsair DIMMs show the bottom one as 512MB.
Was the wrong one used for the photo?
JarredWalton - Friday, August 4, 2006 - link
The model name is correct at the top of the sticker, so I'm guessing it's a pre-release sample and the "512MB" is simply a typo. As Wes mentions, it doesn't appear that Corsair has an equivalent 2x512MB kit (yet?).CrappyLuckMan - Friday, August 4, 2006 - link
I would still like to see how budget DDR2-800 performs too. For some reason you guys left them out of the feeding the monster article. Do you guys think it's better to just go with value PC5300/5400 and overlock it? However, I would think you could overlock value DDR2-800 to around 1000mhz. In honesty I'm posting this out of selfishness since I ordered Corsair XMS2 1GB kit (my games I run never hit 1GB PF usage) TWIN2X1024-5400C4 4-4-4-12 1.9V for $108 is great for relatively low latency low voltage highly compatible ram.Your articles with specifics such as voltage and latencies you use for stable overclocks really save us users some time and we thank you for that.
CrappyLuckMan - Friday, August 4, 2006 - link
Oops made a bad com error. I should mention I meant to say it would be nice to compare which is better, lower latency lower voltage value pc5300/5400 or higher volt higher latency value pc6400 ram. Sorry tired from waiting on news for new motherboards last night lol.EarthsDM - Friday, August 4, 2006 - link
Wesley,In the discussion of his article, “Conroe Buying Guide: Feeding the Monster” (July 19th, 2006) Gary Key replied to a question on G.Skill memory, saying “We still have additional memory selections from a variety of suppliers arriving for further memory reviews at this time.” Is this what he meant, or are you guys going to review the G.Skill? I don’t want to sound ungrateful for the reviews you do, but G.Skill is a memory that of a lot of us (system builders) are interested in because it seems to offer the best performance/price.
On a separate but related note, do you know when the next round of motherboard reviews will be posted? I’m sitting on some Core 2 Duos and I need systems to put them in for back-to-school. Thanks a bunch!
-EarthsDM
Wesley Fink - Friday, August 4, 2006 - link
We have the latest G. Skill on the way. We will schedule a review when it arrives.EarthsDM - Friday, August 4, 2006 - link
Thanks!yacoub - Friday, August 4, 2006 - link
The enthusiast, by definition, is always looking for more - more speed, more power, more performance. The quest is for the best - performance so good and speeds so fast that no one can touch their results. You may even consider the enthusiast an elitist, but that is no different than the car enthusiast, a photography enthusiast, or any technology area where hobbyists can be found.Well that's your opinion and I'd disagree with it. Enthusiast does not always equal elitist (in fact it rarely does) nor a need to have the most expensive and latest item. One can be an enthusiast of cars without owning an exotic supercar. One can be a photography enthusiast without ever taking a picture, but simply appreciating the work of others.
I'm not picking a nit, but pointing out the fallacy that if you buy the most expensive and newest item you must be an ethusiast. On the contrary, (reviewers excluded) you're most likely just a sucker for marketing or poor monetary management.
Most computer enthusiasts for that matter are much more interested in building the best bang-for-the-buck system, not the most expensive one they can find, and generally not even using the latest parts. I would say the overclocker is the epitome of the computer enthusiast, as 'he' not only looks for the best performance but often elicits it 'him'self by taking budget parts and using 'his' knowledge and resources available, runs them at the speeds of much more expensive items, thus getting the best of both worlds - cost and performance.
Just a thought.
Wesley Fink - Friday, August 4, 2006 - link
The most expensive is not always the best performance, as we have pointed out many times. The enthusiast seeks the best. The quest for best performance for "x" dollars is also seeking the best. So is overclocking a cheap part for best performnace.I suppose my point was that the enthusiast is not one to "settle" for mediocrity or buy a cookie-cutter system. Your points are well taken and I am in basic agreement.
yacoub - Friday, August 4, 2006 - link
Then they aren't elistists, as elistist brings to mind a rich person who just buys the latest and greatest because 'it is'. Overclockers are economical people to a fault. The two don't match up, hence the discrepancy. =)