Conclusion
While DDR2 Memory does not exhibit the same bandwidth or performance on the AM2 and Conroe platforms, they do perform at the same timings and voltages when going from one platform to another. This was clearly demonstrated in benchmarking tests performed on AM2 and Conroe platforms. This means readers can examine test results performed on a Core 2 Duo test bed with XYZ memory, and reasonably expect that XYZ memory to perform at the same speeds and the same memory timings and voltages on an AM2 platform - provided those settings are available.
There are always the variations in chipset and BIOS that can cause problems with a memory on one brand/model of motherboard and no problems on another brand/model, but that is also true even if you are planning to use the DDR2 on the same type of platform. We have sometimes seen where a brand of memory runs very well on an MSI platform, for example, but where it would not run at all on a DFI platform using the same chipset and CPU. Those types of compatibility issues will always happen, but in general if a memory tests well on Conroe it should do just as well on AM2.
This fact will make our memory testing much simpler, and we plan to perform all upcoming memory testing on the currently more flexible Core 2 Duo test platform. AM2 buyers can expect similar results with the same DDR2 memory on their AM2 motherboards.
A few conclusions about AM2 performance compared to Core 2 Duo performance are also inescapable in looking at our test results. First, Intel has done a remarkable job of concealing the issue of not having an on-processor memory controller. The intelligent look-ahead for memory works very well, and it makes the chipset-based Core 2 Duo memory controller appear to be as fast as the on-processor AM2 in many cases. This does not change the fact that the AM2 memory bandwidth is really greater than Core 2 Duo or the fact that AM2 scales better in memory, exhibiting a steeper slope in performance increase as memory speed increases than does Core 2 Duo. That just means as Memory Speed increases AM2 will benefit more and Intel will eventually need to move to an on-processor controller.
Probably the hardest conclusion for many will be the fact that increasing memory speed, increasing clock speed, and increasing CPU speed alone will not be enough for AM2 to catch up to Core 2 Duo in performance. The performance gap that remains when overclocking AM2 to 2.93GHz at 266 clock speed with DDR2-1067 is still huge. A die-shrink from 90 to 65nm and the additional cache that will allow will definitely help, but we are even skeptical there with Core 2 Duo already overclocking to 4GHz and beyond. No doubt AMD will find a solution, but it is now clear this will not be an easy fix for AMD.
The deep price cuts announced by AMD yesterday will definitely help. The new numbers indicate AM2 will be very competitive at the low end to low-mid of the processor food chain - a spot they have held in the past and where they have still managed to survive. The low end looks very competitive, and AMD is positioned close enough to mid-range in performance to keep Intel honest. There is no mistaking, however, that Intel Core 2 Duo owns the mid to high-end of the current processor market.
With this memory analysis, the memory playing field is hopefully a lot clearer for those shopping for DDR2 memory. Our next memory articles will compare memory performance of DDR2 on the Core 2 Duo Memory Test Bed. This began with the 6 high-performance memories and the 7 value memories tested in the Conroe Buyers Guide. It will continue with evaluations of the fastest memories available from both Corsair and OCZ.
While DDR2 Memory does not exhibit the same bandwidth or performance on the AM2 and Conroe platforms, they do perform at the same timings and voltages when going from one platform to another. This was clearly demonstrated in benchmarking tests performed on AM2 and Conroe platforms. This means readers can examine test results performed on a Core 2 Duo test bed with XYZ memory, and reasonably expect that XYZ memory to perform at the same speeds and the same memory timings and voltages on an AM2 platform - provided those settings are available.
There are always the variations in chipset and BIOS that can cause problems with a memory on one brand/model of motherboard and no problems on another brand/model, but that is also true even if you are planning to use the DDR2 on the same type of platform. We have sometimes seen where a brand of memory runs very well on an MSI platform, for example, but where it would not run at all on a DFI platform using the same chipset and CPU. Those types of compatibility issues will always happen, but in general if a memory tests well on Conroe it should do just as well on AM2.
This fact will make our memory testing much simpler, and we plan to perform all upcoming memory testing on the currently more flexible Core 2 Duo test platform. AM2 buyers can expect similar results with the same DDR2 memory on their AM2 motherboards.
A few conclusions about AM2 performance compared to Core 2 Duo performance are also inescapable in looking at our test results. First, Intel has done a remarkable job of concealing the issue of not having an on-processor memory controller. The intelligent look-ahead for memory works very well, and it makes the chipset-based Core 2 Duo memory controller appear to be as fast as the on-processor AM2 in many cases. This does not change the fact that the AM2 memory bandwidth is really greater than Core 2 Duo or the fact that AM2 scales better in memory, exhibiting a steeper slope in performance increase as memory speed increases than does Core 2 Duo. That just means as Memory Speed increases AM2 will benefit more and Intel will eventually need to move to an on-processor controller.
Probably the hardest conclusion for many will be the fact that increasing memory speed, increasing clock speed, and increasing CPU speed alone will not be enough for AM2 to catch up to Core 2 Duo in performance. The performance gap that remains when overclocking AM2 to 2.93GHz at 266 clock speed with DDR2-1067 is still huge. A die-shrink from 90 to 65nm and the additional cache that will allow will definitely help, but we are even skeptical there with Core 2 Duo already overclocking to 4GHz and beyond. No doubt AMD will find a solution, but it is now clear this will not be an easy fix for AMD.
The deep price cuts announced by AMD yesterday will definitely help. The new numbers indicate AM2 will be very competitive at the low end to low-mid of the processor food chain - a spot they have held in the past and where they have still managed to survive. The low end looks very competitive, and AMD is positioned close enough to mid-range in performance to keep Intel honest. There is no mistaking, however, that Intel Core 2 Duo owns the mid to high-end of the current processor market.
With this memory analysis, the memory playing field is hopefully a lot clearer for those shopping for DDR2 memory. Our next memory articles will compare memory performance of DDR2 on the Core 2 Duo Memory Test Bed. This began with the 6 high-performance memories and the 7 value memories tested in the Conroe Buyers Guide. It will continue with evaluations of the fastest memories available from both Corsair and OCZ.
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HSuke - Thursday, July 27, 2006 - link
I hope this means that you're going to do the tests on the Core 2 Duo test platform IN ADDITION to your current platforms.
I hope this does NOT mean that you're going to do the tests EXCLUSIVELY on the Core 2 Duo test platform.
So are you going to stop doing memory tests with AMD processors? How scientific is that? If you go to page 7 and look at the performance charts, you'll see that memory speeds have a much greater impact (pertage-wise) on the AMD setup than the Core 2 Duo setup.
Well, I'm quite surprised that memory even made a difference. But since that is true (according to your tests), shouldn't be testing on AM2 instead of Core 2 Duo processors in the future because the difference is more marked? If there wasn't any significant difference on an Intel system, but a significant difference on an AMD system, you'd probably suggest that memory doesn't make a difference, commiting a type 2 error.
Now, I don't care about memory. I always buy whatever is on sale. But making that conclusion would just piss off so many memory enthusiasts and memory sellers. And aren't those guys the ones that would be reading this article?
Think about it.
Wesley Fink - Friday, July 28, 2006 - link
As we explained in the article, AM2 currently does not support the DDR2-1067 speed, while the Intel chipset for Core 2 Duo DOES support 1067. Since most memory we test can reach 900 to 1067 or 1100 or greater the 1067 ratio is an advantage. Also the current AM2 memory controller does not support settings of 2 for Ras-to-Cas or tRef - AM2 only supports to 3. Core 2 Dupo supports faster timings of 2 at these settings. Since these lower settings are often usable in fast memory they can be very important.For these reasons, we will be using the Core 2 Duo platform for testing DDR2 memory, since we can test more of the options that are available and may be important on high-performance DDR2 memory. If and when AM2 upgrades their DDR2 memory controller we will reconsider testing on AM2.
Kiijibari - Wednesday, July 26, 2006 - link
Hi everybody,first of all I have to admit that this is the best Anandtech article for a long time. Everybody blamed me for being an AMD fanboy latley, however I do not have any problems to admit that Core2 is faster.
If Intel would not have anything faster than AMD after 3 years of AMD lead, Intel would be best adwised to stop making CPUs and become an AMD chipset company ;-)
I have one question left: Which BIOS version did you use with the AM2 board ?
I recoginzed that DDR2 bandwidth scores increased quiet much compared to the initial tests. Now we have Sandra scores around 9.3 GB/s, however I remember that the initial ones were around 7.4 GB/s max.
In conclusion I assume that there is some optimization going on, due to bios seetings.
There was also a little test over at lostcircuits:
http://www.lostcircuits.com/motherboard/foxconn_c5...">http://www.lostcircuits.com/motherboard/foxconn_c5...
There the Asus board scored just ~7 GB/s, but a tested Foxconn board is again in the 9GB/s area.
It maybe that the BIOSes are optimized for different kind of RAMs, too, as lostcircuit used OCZ memory, not Corsair.
Anyways, I think the results are interesting enough to dig a little bit further ;-)
Thanks again for the great review.
regards
Kiijibari
Wesley Fink - Wednesday, July 26, 2006 - link
P5W-DH Deluxe BIOS is 701, dated 7/08/2006. The Corsair memory used in this review can do 4-3-4-11 timings at DDR2-1067, where most high-end DDR2 can only reach 4-4-4 timings at that speed.Kiijibari - Wednesday, July 26, 2006 - link
Sorry, looks like you misunderstood me, I was wondering about the AM2 platform bandwidth results @2.8Ghz and DDR2-800(page3). The Core2 scores are the same as "usual" ;-)So can you also say which bios you were using for the Asus M2N32-SLI ?
thanks a lot
Kiijibari
Gary Key - Thursday, July 27, 2006 - link
0603 - 6/29/06
OcHungry - Wednesday, July 26, 2006 - link
But I dont understand why you need DDR2 800 or 1000?DDR2 667 w/ tighter timings can run @ 333 1:1 ratio (333x9 for FX62).
Tell me what I am missing here?
zsdersw - Thursday, July 27, 2006 - link
Understatement of the year.
zsdersw - Wednesday, July 26, 2006 - link
Interesting notion. If it ever came to be, you can kiss price cuts (and innovation) on AMD chips goodbye.
Shizen - Tuesday, July 25, 2006 - link
Intel Core 2 comes out and AMD slashes prices across the board... the months ahead look like a great time to buy a new rig! Finally, I can retire my aging 2.8GHz Northwood and move on to PCI-E and DDR2. *_*Many thanks to the AnandTech dudes for keeping us abreast with the CPU wars, and I personally hope you guys come out with more articles geared for the midranged ($1000-$1500) buyer.
Yeah, I like the idea of being a PERFORMANCE fanboi rather than a brand-centric one. o_o