Intel's Pentium Extreme Edition 955: 65nm, 4 threads and 376M transistors

Presler vs. Smithfield - A Brief Look

Other than the larger L2 cache, Presler as incorporated in the Pentium Extreme Edition 955 provides us with two more enhancements over Smithfield: 1066MHz FSB support and a higher clock speed (3.46GHz).

We wanted to isolate the performance improvement due to the larger L2 cache aside from the other improvements to Presler, so we underclocked our sample and its FSB, and compared it to a Pentium D 820 (2.8GHz). 

Looking at a small subset of our tests, we can get a feel for where you can expect the largest performance gains due simply to the increase in L2 cache size.  Remember that since L2 access latency on Smithfield was already at 27 cycles, Presler's cache isn't any slower, so what we end up measuring is how large of an impact a 2MB cache has in some of our benchmarks. 

Winstone	Business Winstone 2004	Multimedia Content Creation Winstone 2004
Presler	19.0	30.2
Smithfield	18.5	29.9

Under Business Winstone 2004, we see a boost of just under 3%, thanks to the larger cache size.  We have seen the biggest improvements in Winstone, thanks to lower latency caches and higher clock speeds, so it's not too much of a surprise to see a minimal impact here.  Content Creation Winstone 2004 shows no real performance impact either. 

Media Encoding	3dsmax 7 Composite	DVD Shrink	WME9	H.264	iTunes
Presler	2.03	9.1m	31.3fps	10.5m	50s
Smithfield	2.05	8.9m	31.0fps	10.5m	50s

Our 3D rendering, video encoding and audio encoding tests basically all agree with the earlier results - the added cache doesn't really improve performance here, but that's to be expected, given the nature of the applications (and the already quite large 1MB L2 cache to which we are comparing). 

Gaming	Battlefield 2	Call of Duty 2	Quake 4
Presler	77.3	76.2	130.6
Smithfield	73.0	75.6	125.5

It isn't until we look at some of our 3D gaming tests that we start to see some more tangible performance gains.  In games, there are some decent performance improvements to be had, ranging anywhere from 0 to just under 6%, thanks to the larger cache alone. 

Couple the larger cache with a faster FSB and higher clock speed, and the Pentium Extreme Edition 955 is shaping up to be a decent improvement over its predecessor.