AMD Phenom II X4 940 & 920: A True Return to Competitionby Anand Lal Shimpi on January 8, 2009 12:00 AM EST
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Phenom vs. Phenom II - Clock for Clock
Before we get to how fast this thing is, it's important to look at how much faster we are compared to the original Phenom. Clock speed alone should be able to deliver a good 5 - 15% performance improvement, but the larger L3 cache and other fixes included in the chip should account for more.
In order to find out how much more performance the L3 changes bring, I performed a very simple experiment: I took a Phenom 9950BE and overclocked it to 2.8GHz. I then compared it to a Phenom II X4 920, also running at 2.8GHz. I chose a subset of the test suite I ran for today's review, but it should be enough to give you an indication of what the more balanced cache hierarchy does for performance:
|Processor||Excel Monte Carlo (lower is better)||Adobe Photoshop CS4 (lower is better)||x264 Pass 2||3dsmax 9||Cinebench||WinRAR (lower is better)||Left 4 Dead||FarCry 2|
|AMD Phenom II X4 920 (2.8GHz)||31.3s||25.8s||16.6 fps||10.2||11440||123s||110.2 fps||43.3 fps|
|AMD Phenom @ 2.8GHz||43.4s||27.9s||15.9 fps||9.6||10948||144s||99.8 fps||42.1 fps|
The performance improvements here are good - very good. At the high-end we see a nearly 30% gain at the same clock speed and at the low end a 2.9% increase at 2.8GHz.
These applications span the gamut, including everything from a high-end financial model simulation with the Excel test, to basic file compression with WinRAR. Phenom II offers real world benefits over the original, largely due to its more balanced cache structure. With enough L3 cache for all cores to be fed, no one is left hungry.
We see the potential for real performance improvements in gaming as compared to the original Phenom, which could restore AMD's competitiveness in an area where it has been forced to rely on also having a strong GPU for quite some time now. All in all, the performance improvements and changes to cache structure we've been talking about over the past few pages are real - Phenom II is better than the original. But is it good enough?