The technology launch of Intel's new G35 chipset - the first to support DDR3 - occurred just 3 days ago. At launch most reviewers were intrigued by the potential of DDR3 but less than excited about the high latencies and high prices that were available at launch. As you saw in Intel P35: Intel's Mainstream Chipset Grows Up and Intel P35 Memory Performance: A Closer Look our first two samples of DDR3 were rated at DDR3-1066 and 7-7-7-20 timings. These DIMMs would also run at DDR3-1333 with 9-9-9-25 timings. While performance at both speeds was promising, we were left to wonder when lower latency DDR3 might become available.
The higher latency DDR3 at launch certainly gave the top DDR2 a run for the money, but it generally took much higher speeds to match or surpass current DDR2 with low latency timings. It was clear lower latency would bring DDR3 much improved performance and make it even more attractive to buyers, but we assumed it would likely be months until we saw lower latency DDR3 - as it was in the launch of DDR2.
With this scenario, imagine our surprise when Kingston asked us if we would like to review their first low-latency DDR3. Where the competition was 9-9-9 at DDR3-1333 and 7-7-7- at DDR3 1066, Kingston specified their new DDR3 memory at 7-7-7 at 1333 and 6-6-6 at 1066. These were definitely some memory sticks we wanted to review.
If these numbers still seem high to you, you need to back up a bit for a larger perspective. While lower speed DDR2 can have latencies as fast as 3, DDR3 starts at 800 and the boards we have seen only allow CAS latencies as low as 5. The CAS range on better P35 boards is normally 5 to 10. Given this range of available latencies at higher speeds than DDR2, it is clear the new Kingston KHX11000D3llK2/2G has found ways to provide the lowest latencies so far in DDR3.
Keep in mind that the actual latency in nanoseconds is what really matters, so while the number of memory cycles from DDR2-533 CL3 through DD2-667 CL4, DDR2/3-800 CL5, DDR3-1067 CL7, and DDR3-1333 CL9 increases, the actual latency in ns only ranges from 11.25ns (DDR2-533 CL3) to a maximum of 13.5ns (DDR3-1333 CL9). While CL7 may sound like a high latency, achieving that with 1333 MHz memory is actually results in a time latency of 10.5ns, and of course that's with much higher bandwidth than some of the other memory speeds.
We presented detailed comparisons of memory performance on the current P965, DDR2 on the P35, and DDR3 on the P35 just last week. This allowed us to run a full suite of comparison tests using the same configurations used in Intel P35 Memory Performance: A Closer Look. Those wondering whether DDR3 can compete with low-latency DDR2, and when that might happen will get some answers to their questions in this comparison.
The higher latency DDR3 at launch certainly gave the top DDR2 a run for the money, but it generally took much higher speeds to match or surpass current DDR2 with low latency timings. It was clear lower latency would bring DDR3 much improved performance and make it even more attractive to buyers, but we assumed it would likely be months until we saw lower latency DDR3 - as it was in the launch of DDR2.
With this scenario, imagine our surprise when Kingston asked us if we would like to review their first low-latency DDR3. Where the competition was 9-9-9 at DDR3-1333 and 7-7-7- at DDR3 1066, Kingston specified their new DDR3 memory at 7-7-7 at 1333 and 6-6-6 at 1066. These were definitely some memory sticks we wanted to review.
If these numbers still seem high to you, you need to back up a bit for a larger perspective. While lower speed DDR2 can have latencies as fast as 3, DDR3 starts at 800 and the boards we have seen only allow CAS latencies as low as 5. The CAS range on better P35 boards is normally 5 to 10. Given this range of available latencies at higher speeds than DDR2, it is clear the new Kingston KHX11000D3llK2/2G has found ways to provide the lowest latencies so far in DDR3.
Keep in mind that the actual latency in nanoseconds is what really matters, so while the number of memory cycles from DDR2-533 CL3 through DD2-667 CL4, DDR2/3-800 CL5, DDR3-1067 CL7, and DDR3-1333 CL9 increases, the actual latency in ns only ranges from 11.25ns (DDR2-533 CL3) to a maximum of 13.5ns (DDR3-1333 CL9). While CL7 may sound like a high latency, achieving that with 1333 MHz memory is actually results in a time latency of 10.5ns, and of course that's with much higher bandwidth than some of the other memory speeds.
We presented detailed comparisons of memory performance on the current P965, DDR2 on the P35, and DDR3 on the P35 just last week. This allowed us to run a full suite of comparison tests using the same configurations used in Intel P35 Memory Performance: A Closer Look. Those wondering whether DDR3 can compete with low-latency DDR2, and when that might happen will get some answers to their questions in this comparison.
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goinginstyle - Thursday, May 24, 2007 - link
How did you arrive at the 1520 DDR3 memory speed? FSB increase from 8x333 or a memory ratio change. Do you have any overclocked DDR2 memory scores on the P965? It would be interesting to compare overclocked DDR2 to DDR3.Wesley Fink - Thursday, May 24, 2007 - link
You can look back at the Corsair Dominator memory review where we ran benchmarks at the highest overclock we could achieve. THe review is at http://www.anandtech.com/memory/showdoc.aspx?i=291...">http://www.anandtech.com/memory/showdoc.aspx?i=291.... THere are also overclocked test scores that can be compared in any of our more recent DDR2 reviewsWesley Fink - Thursday, May 24, 2007 - link
From the 1333 memory setting we overclocked to 380x8, or 3.04GHz. At that OC, with a base 1333 memory setting, the memory speed is 1520.One reader pointed out that 7x380 is also 2.66, which is our test frequency at other speeds. That is correct and it is an intriguing idea to also run all benchmarks at the 380x7 speed. We'll consider for a comparison in an upcoming review.
goinginstyle - Thursday, May 24, 2007 - link
So it is very possible that the improvements in scores came from the increase in cpu speed and not the memory or it is a combination of both? How close can you get to 1333 memory speed at 8x380 so we know how much improvement there is in cpu speed over the increase in memory speed.
That is what has been confusing to me. Why not run at 7x380 to keep the CPU at the same speed so we can see how much performance is gained in running the memory higher. The one flaw is the increase in FSB speed would alter the scores if the app responds to cpu throughput improvements. I would suppose that would be minimal in the game testing but it would throw off the sandra scores. Does high memory speeds at high latencies beat stock memory speeds at low latencies?
The article yesterday mentioned 1t command rates. Did you try 1t to see what happened with the Kingston memory? You used to report Everest scores and I was wondering if those scores are available or maybe Memtest if you use it. I think it would be interesting to see latency numbers in the article.
Wesley Fink - Thursday, May 24, 2007 - link
Our standard procedure has been to test to the highest available memory setting, in this case 1333, and then overclock as far as we can go using this base memory setting. It is just a fortunate accident that 1520 was top OC here (and it still wasn;t the fastest results - 1500 7-7-7 was faster)which is also 7x333 or the same 2.66 used in the other memory speed tests. It would not likely hit that exact number again in future DDR3 reviews.yuchai - Thursday, May 24, 2007 - link
the 1520 speed is probably achieved by a 380 x 7 = 2660 configuration, so processor speed remains constant while the RAM runs at 1520 speeds.That said I'm surprised at the big improvement from 1333 to 1520, especially compared to the relatively small difference between 1333 and 1066.
goinginstyle - Thursday, May 24, 2007 - link
If that is the case then how do we know how much the FSB increased the score or how much the memory affected the results. I still think it is important to show overclocked DDR2 if they are going to show overclocked DDR3.
Chunga29 - Thursday, May 24, 2007 - link
I wish that you were correct, but looking at the tables at least on says "8x380" - page 4. So it's not apples to apples. The text never talks about how fast the 1520 RAM speed is, likely because that's partly due to a 14% CPU overclock.While we're at it, where are the numbers for P965 with 1333 FSB? We've seen overclocking results on P965 with bus speeds as high as 2000+, so don't give us any excuses about it not being possible. Using ratios, you can come somewhat close to DDR2-800 and DDR2-1066, and if you're throwing in overclocked DDR3 scores anyway.... At least let us see what DDR2 can achieve on P965 with a decent effort. Sure, it's out of official spec, but then DDR2-800 with 3-3-3 timings isn't JEDEC spec either.
Wesley Fink - Friday, May 25, 2007 - link
The 7x380 and 8x380 results are in a comment below and will be added to the OC section in a table.As for the P965, it was not designed to run 1333 processors or DDR3 memory, so there is no 1333 CPU raio available or any memory ratio above 1066. While it is true you can run a 25% overclock at 1333 FSB, the memory is also overclocked 25% from whatever ratio you selected. Even if you OC and select to get close to 1333 you will be running different memory straps on the P35 and P65 which definitely impacts results. It is very difficult to fairly compare P965 to P35 at speeds above 1066.
At 1333 FSB the DDR2 memory is OC'ed from the 1066 base to 1333, and we don't have a single stick of DDR2 that is stable at 1333. An 800 speed base on P965 at 1333 would be DDR2-1000, which should be compared to what on the P35? Try to select OC vlues on your P965 board to see what we are talking about here.
You are correct that it is is not impossible to come up with something somewhat close in a P965 test, it is just everything on the P965 would be overclocked while P35 would be running in spec. We can always compare an overclcoked P965 to a spec part, but is that more like justification for a P965 purchase than a revealing comparison.
We will likely run some more P965 tests just to answer questions here, but we will only be including overlap speeds, where comparisons can be fairly made, in future reviews. There are also a multitude of P965 OC results in reviews out there for those that are interested.
Zaitsev - Thursday, May 24, 2007 - link
I noticed this as well. It just seems odd because the jump from 1066->1333 is 267MHz, while 1333->1520 is 187MHz. In Far Cry and Quake 4 that translated into 10.91 and 8 more frames per sec. respectively. Did I miss something in the article or can someone explain why a smaller increase in MHz yielded a larger improvement?Oh, I see now that the processor is overclocked.