Intel Core Duo (Yonah) Performance Preview - Part II
by Anand Lal Shimpi on December 19, 2005 12:55 PM EST- Posted in
- CPUs
The Test
CPU: | AMD Athlon 64 X2 4200+ (2.2GHz/512KBx2) AMD Athlon 64 X2 3800+ (2.0GHz/512KBx2) AMD Athlon 64 X2 2.0GHz/1MBx2 Intel Pentium M 760 (2.0GHz/2MB) Intel Core Duo T2500 (2.0GHz/2MB) |
Motherboard: | ASUS A8N-SLI Deluxe AOpen i915Ga-HFS Unnamed 945G Yonah Motherboard |
Motherboard BIOS: | ASUS: Version 1013 Dated 08/10/2005 AOpen: Version 1.11 Dated 11/15/2005 |
Chipset: | NVIDIA nForce4 SLI Intel 915 Express Intel 945G |
Chipset Drivers: | nForce4 6.66 Intel 7.0.0.25 |
Memory: | OCZ PC3500 DDR 2-2-2-7 DDR2-533 4-4-4-12 |
Video Card: | ATI Radeon X850 XT NVIDIA GeForce 7800GTX |
Video Drivers: | ATI Catalyst 8.173.1.2 NVIDIA ForceWare 81.85 |
Desktop Resolution: | 1280 x 1024 - 32-bit @ 60Hz |
OS: | Windows XP Professional SP2 |
While we used an NVIDIA GeForce 7800 GTX for almost all of our tests, there was one exception, thanks to a NVIDIA driver bug. With dual core processors, NVIDIA's 81.95 drivers will cause the system to maintain 100% CPU utilization when running 3dsmax 7, even when the system is actually not doing anything at all. We didn't discover this bug until we had already run the majority of our tests using the 7800 GTX. So, for the 3dsmax 7 tests, we switched to an ATI Radeon X850 XT. The GPU doesn't impact CPU rendering performance at all, so it doesn't change the performance characteristics of the platform. We just wanted to point out the bug, in case any of you were wondering why your dual core platforms were behaving strangely in certain applications. NVIDIA is aware of the problem and is working on a publicly available fix.
For this comparison, we've kept the number of CPUs to a minimum, focusing on the Pentium M, Core Duo and Athlon 64 X2. The exclusion of the Pentium D was on purpose; we've already compared the Core Duo to the Pentium D in our last article and to put it bluntly, the Pentium D won't really be competition for any of Intel's new architectures. By this time next year, NetBurst will have already been forgotten and the real comparison that matters is how Core Duo stacks up to the Athlon 64 X2, whose architecture is not going the way of the dodo.
As we mentioned earlier in this article, in addition to the X2 3800+ and 4200+, we have included benchmarks of an Athlon 64 X2 running at 2.0GHz, but with a 1MB L2 cache per core (2MB total on die). The point of including this simulated "Athlon 64 X2 4000+" is to answer complaints that the Core Duo has a larger L2 cache than the X2 3800+ and thus isn't a true apples-to-apples comparison. So we've now leveled the playing field even more, and actually given AMD more of an advantage - the 2.0GHz/1MB L2 Athlon 64 X2 has a larger L1 cache (128KB per core vs. 64KB per core), and of course, the X2 still has its own on die memory controller.
With that said, let's see how things stack up now...
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Furen - Monday, December 19, 2005 - link
The P6 has two FP units: An FADD unit and an FMUL unit. One of the big weaknesses of the P6 is the fact that the FMUL unit is not fully-pipelined but instead uses part of the FADD unit for FMUL operations. The K7, on the other hand, has three fully-pipelined units, an FADD, an FMUL and an FSTORE.tayhimself - Monday, December 19, 2005 - link
No he's not. AT's hardware reviewers are nublets. One thing to note though, Dothan FPU is better than the P4's hence its gaming performance advantage over the P4 in the old tests that everyone saw. It's likely that Yonah FPU is still the same as Dothan (similar to P3) and inferior to AMD's.saratoga - Monday, December 19, 2005 - link
Actually the FPU on the P4 was tremendously more powerful then Dothan or Yonah. While games do use the FPU, they're not that bottlenecked by it on modern systems. The reason Dothan did so well was because of its large, very low latency L2 cache. This is roughly equivilent to the primary advantage of the K8, a very low latency memory controller.tayhimself - Monday, December 19, 2005 - link
Youre right about the low latency L1/L2 caches on the Dothan, but the P4 (Williamette/Northwood) has those as well. But the P4 FPU is only powerful in SSE2 mode where it can load store larger chunks of data. Not all games use that unfortunately.saratoga - Monday, December 19, 2005 - link
You're wrong on several points.First:
Dothan L2 latency (clks): 10 clks
Northwood L2 latency (clks): 18 clks (approximately)
So Dothan's L2 cache is roughly 2x as fast and 4x as large. If you compare prescott with its amazingly slow L2, the situation is even more biased towards Dothan. Clearly, in terms of cache performance Dothan has a massive advantage, at least once you're out of the L1.
Second, you're confusing SSE2 and vector processing. While SSE2 can perform vector ops, it also handles plan scaler as well. In x86-64 SSE actually replaces the traditional x87 unit. The relative performance of the two is irrelevent however, the P4 was faster in both.
coldpower27 - Monday, December 19, 2005 - link
Dothan I agree with as having 10 Cycle Cache.
Northwood has 16 Cycle Cache.
Well you also got to keep in mind northwoods clock frequency plays a role in speeding up the cache, accces latencies for Dothan @ 2.0GHZ vs Northwood @ 3.2GHZ are basically equivalent. Though the 2.26GHZ Dothan has the fastest cache of all.
AlexWade - Monday, December 19, 2005 - link
Although, "Core Duo" is a stupid name. Why does Intel have to be so different? "Core Duo" is a little confusing. Is Duo a code name? What?However, despite the stupid name, we've really turned a corner in performance. Intel can make a good CPU when they realized speed isn't the future. Looks like I should start considering replacing my old Pentium-M IBM T40p with the awesome battery life.
AMD needs to respond in kind with a great new CPU. The future looks bright. Competition is once again is good for everyone.
LuxFestinus - Tuesday, December 20, 2005 - link
The ambiguously gay duo, with Ace and Gary.:) An old SNL skit.ksherman - Monday, December 19, 2005 - link
Personally, i dont like that AMD is just sitting back, seemingly waiting for Intel to catch up... They need to kick Intel while their down. these new Processors from intel look really nice and i am likely to buy one, but in a mactel laptop. I am happy for INtel that they are catching up, but AMD really NEEDS to step up and do soemthing new.Calin - Tuesday, December 20, 2005 - link
AMD's income is lower than Intel uses for R&D. You really can't expect from AMD to develop something faster than Intel can.For AMD, to have an processor they could improve a step at a time since the introduction of the Athlon64/Opteron was a need - Intel is able to mantain several teams for microprocessor development, but AMD only has money for one. And AMD will milk the market for as much as possible, selling processors that are easy to make for prices that market will accept. If AMD will start selling a higher processor grade, they would need to reduce the price for lower speed processors. This is why the 2800+ and 3000+ are discontinued - they would have to sell them too cheap.