The Test
Unfortunately the platform that we were testing on would only allow us to run our DDR2-800 at 4-5-4 timings, instead of the 3-3-3 that's possible with this memory on socket 775. That hurts performance a bit, but the real world difference between 4-5-4 and 3-3-3 isn't going to be more than a few percentage points.
The only DDR2-800 we had on hand was in the form of 1GB modules, so we had to use a pair of 1GB DDR-400 which ran at 2-3-2, instead of the 2-2-2 we normally run with our smaller 512MB modules. Once again, the difference in performance isn't tremendous, but we wanted to explain why the timings were different than what we've used in the past.
Both our Socket-AM2 and Socket-939 Athlon 64 X2 processors ran at the same clock speed with the same cache sizes, so the results should give us a clear indication of whether or not AM2 is faster than equivalent 939 configuration.
| CPU: | AMD Athlon 64 X2 Socket-AM2 AMD Athlon 64 X2 Socket-939 |
| Motherboard: | ASUS A8N32-SLI (Socket-939) Unnamed MCP55 Socket-AM2 Motherboard |
| Chipset: | NVIDIA nForce4 SLI x16 NVIDIA MCP55 |
| Chipset Drivers: | nForce4 6.70 |
| Hard Disk: | Seagate 7200.9 300GB SATA |
| Memory: | OCZ PC8000 DDR2-800 4-5-4-15 (1GB x 2) OCZ DDR-400 2-3-2 (1GB x 2) |
| Video Card: | NVIDIA GeForce 7800 GTX |
| Video Drivers: | NVIDIA ForceWare 84.21 |
| Desktop Resolution: | 1280 x 1024 - 32-bit @ 60Hz |
| OS: | Windows XP Professional SP2 |
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sprockkets - Monday, April 10, 2006 - link
No one thought that making a more capable ILP was possible, but intel proved that wrong. They all thought ILP was dead due to the P4, which is ironic.Would I wait for AM2? Why? Crucial Ballistix Ram in DDR-400 is $95 for 512x2, whereas DDR800 is $185.
NO. Little to nothing is not worth $90 in memory plus a premium in boards and processor prices.
sprockkets - Monday, April 10, 2006 - link
I mean ddr2-800flemlion - Monday, April 10, 2006 - link
This seems to be just a quicky review. In the conclusion it is mentioned that the usefullness of memory bandwith increases as the CPU clock speed increases. But still a lower speed was used for this test than for the DDR1-400 versus DDR1-500 evaluation. It seems to me at least this test should either have been done at different speeds to get a feel of this impact or at minimum at the same speed of the DDR1-400 versus DDR1-500 article.As a sidenote, it's also interesting to see that the test config has no mention of the CPU speed that was used. If this is NDA, then say so, if not it just appears as hiding the details that would expose this article as gossip instead of information.
andrewln - Monday, April 10, 2006 - link
I meant...Intel will see how the next generation of AMD works just 5% faster....wouldn't they tune down conroe to match or make it just a bit faster than AMD and sell at the premium price? Since the demand will be almost the same.
1) AMD fanboi will keep on buying AMD
2) Intel fanboy will keep on buying Intel
3) But this time, people that wants performance, will be buying Intel (even though its only a 10% faster than the competitor, or 40$)
This way, when AMD makes a new gen of procesor, Intel only have to tune up Conroe which is cheaper than making another big modification that might or might not work.
Conroe - Monday, April 10, 2006 - link
They said 20%, and thats where they plan on staying. Theu could have more. The FX-62 has extra cache, it may give 10% who knows?Anand Lal Shimpi - Monday, April 10, 2006 - link
Every FX-62 I've seen hasn't had any more cache than what's in the table in the review.Take care,
Anand
Dfere - Monday, April 10, 2006 - link
I’ve got to disagree- I don’t think this makes sense to even upgrade from a 754 system to AM2.Why? Because if you remember Nforce 2- and all the Mb’s with “future- proof” DDR-400 systems, the MB makers did not live up to their claims. For most recognized mfg’s it took the revision after DDR-400 memory was available before most of them got it right.
So I don’t see where AM2 can even be thought of as an upgrade path, especially before final revisions have been made in silicon. A MB you buy initially might work, but with future memory or processors… forget it. Anybody wanna take a bet ($1 will get you $10), that the first MB’s out by lets say- ASUS, do not allow for different memory timings or the latest memory say March of 07?, let alone a top of the line processor, same date?
While the author did say many changes are still in the works, final silicon may not yet even been achieved. How can buying a MB now be considered a possible upgrade in the future?
For this reason, and many price/performance reasons, I have a 754 system, and I will hope that after tax season ends I can build a 939 for a better price. That’s it.
The numbers per the review state this clearly. This is not about performance. And it will be expensive. The analysis on the forum here site seems to indicate that the relative analysis is expected future performance, when Anand admittedly and AMD (by not making announcements about performance) seem to indicate (and I explicitly do) that this is not about performance…. Yet either. So how can this even be recommended as an upgrade path when there is very little real world benefit and future compatibility a MB purchased now and memory or processors is not even known.
I am an avid fan of AMD, but I think excess hype can kill a product as quickly as bad rumors.
HammerFan - Monday, April 10, 2006 - link
I'm suprised that nobody has considered the bottlenecks in AMD's systems as of late. Recently, it seems that all AMD really needs to do with the K8 is keep squeezing more MHz out of it. Clearly the CPU has enough memory bandwidth to spare, so bring the rest of the processor up to speed. IIRC, AMD is starting to implement an improved version of SOI in their new CPU cores (or is it 65nm cores?), which will help increase clock-speed headroom. Also, as quality continues to improve, AMD might be able to add higher clock speeds to take advantage.just my $.02
HF
ozzimark - Monday, April 10, 2006 - link
one thing that would REALLY help K8... follow intel's footsteps with netburst and try to double-pump the ALU. faster SSE execution never hurts either :)still - Monday, April 10, 2006 - link
Double-pumping the ALU is only going to limit scaling and increase heat... what the K8 core really needs is better L1 and L2 cache subsystem.... The L1 is sort of ok but getting old it the same one the K7 (7 year old). They improved the L2 of the K8 over K7 but half heartedly. It still has too narrow of a path and too high of a latency. I can just imagine what the K8 can do with a 4M low latency cache that has 256 or 512 bit width data path (+ ECC of course).While they are there lower the L1 latency to 2 cycles. That alone is 5-10 % improvement.
And they need to seriously improve the SIMD execution units. The current AMD SIMD units are almost as lame as the Intel implementation of AMDs 64bit instructions.
Oh yeaa and write some decent compilers to make use of the 64 bit goodness like extra register - where are the promised 20 % improvements?
The K8 core can scale better than Conroe and can crunch trough more instructions/data if the cache subsystem can feed all these to the execution units. Albeit the K8 has to be clocked slightly higher to do that - such is the tradeoff of 3 vs. 4 IPC.