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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Calin - Tuesday, July 25, 2006 - link
I hate to rain on your parade, but the E6x00 and X6800 (Extreme) desktop CPU won't see a dual socket mainboard - for that you must use Xeons.As for multisocket, it was a niche market when multicore was not available, it is (maybe even more so) when multicore is available. Quad core will reduce it even more for desktop use. As for Intel knowing multicore is the future, I think their quad core will be on market before AMD's quad core - and if you are worrying about performance, keep worrying - we can small talk about this and that all day long.
AMD is in a much weaker position now - they must sell processors at half (or less) the profit they sold them until now, and the future is grim if you regard their profits. They could survive a long way, but they again are the budget CPUs, the best choice for small money.
As for 64-bit, you are certainly right - just that right now, 64-bit is of little use on desktop, the operating systems suffer from drivers problems, 64-bit applications are few and far between. You might need 64-bit and profit from it, but you are a minority now.
Ingas - Tuesday, July 25, 2006 - link
Maybe AMD in trouble.But not because of Core 2 Duo, but because of Woodcrest.
AMD alwais said that only server processors giving profit.
So ...
With Dell's AMD Now - maybe it's not trouble for AMD at all.
Calin - Wednesday, July 26, 2006 - link
Dell will only build enough AMD gear as not to lose business with their customers that WANT AMD gear. Even with higher performance losses on 4 sockets, Xeons Core2Duo (which are faster to boot) might put a fair fight against AMD - and then customers will choose based on other things than performance.I agree AMD Opteron scale better - but they start scaling from a lower performance
duploxxx - Wednesday, July 26, 2006 - link
do you really think you're sure about that. compare the same speed of opteron vs woodcrest and you will talk different.. i know how it performs because i have a wood es system on my table. and i am not a big fan of hexus reviews but look at the site, the wood isn't so bright and shining knowing again it is a compare of 3.0 vs 2.6.mesyn191 - Tuesday, July 25, 2006 - link
For 2S systems Intel will have the lead til' K8L becomes available, but for 4S AMD will have Intel beat and that lead will only increase when K8L becomes available. They're definitly gonna be hurting profit wise, but they'll be doing better than they were when it was P4C vs. AXP and they got through that so I see no reason to worry about them going into bankruptcy before K8L comes out in volume.sld - Tuesday, July 25, 2006 - link
What is wrong with a desktop user looking at the performance of a desktop cpu?When you can get a 4x4 at the same price/performance ratio curve as a Core 2 Duo, do please inform me.
I still believe AMD vs Intel is a David vs Goliath, although like the real David, AMD is beginning to get complacent with just a taste of power, and Core 2 is just what it needs to wake up and start dropping prices. :)
sld - Tuesday, July 25, 2006 - link
I forgot to mention that Core 2 is worth a consideration over the K8, but if we really want to punish Intel for being the monster they are, we should institute a complete boycott over the purchase of their existing Netburst inventory. That should hurt them quite a bit...Picture a scenario where new chips go straight out of the warehouse and into the embracing arm of a bulldozer. When it comes to that point do you think they will resort to giving the cpus away?
mattsaccount - Tuesday, July 25, 2006 - link
Are the Super Pi scores on page 7 right? The text says Conroe wins everything, but the Super Pi bench is reversed (I'm guessing the colors are just backward)Wesley Fink - Tuesday, July 25, 2006 - link
Since the lower score is better on Super Pi (faster time) the scales are reversed - from zero at the top to 90 at the bottom. The colors and values are correct, just upside down so the lowest score (fastest) is on the top like the other charts. You apparently caught that while I was typing this explanation :)highlandsun - Tuesday, July 25, 2006 - link
Have you got 32M digit results for Super Pi? Curious to see if that will exceed Conroe's cache and therefore reflect the real memory bandwidth. Also, results for running two copies of Super Pi at once on each system.