Pentium 4 3.46 Extreme Edition and 925XE: 1066MHz FSB Support is Here

Does it Improve Real World Performance?

There is a convenient convergence point between the 1066MHz FSB and the 800MHz FSB - 3.2GHz. By underclocking our 3.4EE and our 3.46EE to 3.2GHz we managed to put together a nice comparison of the impact of FSB on real world performance, independent of CPU and memory clock speed. Granted, the impact of the 1066MHz FSB will be greater at higher CPU clock speeds, but the impact at 3.2GHz should be able to tell us how much of the 3.46EE's performance advantage is due to its faster FSB.

The table below gives a good indication of the lack of performance improvement due to the 1066MHz FSB today in most applications. With an average performance increase of less than 1%, you shouldn't expect the 1066MHz FSB to do much for Intel at all.

Under Multitasking Content Creation applications we see that despite the nature of these applications to be more memory bandwidth intensive, the 800MHz FSB simply wasn't a limitation for the Pentium 4 Extreme Edition. Couple that with the fact that with a very large on-die L3 cache, the Extreme Edition needs to fetch data across the FSB much less frequently, it's no surprise that the biggest performance improvement in our Multitasking Content Creation tests was only 1.52%.

There's not much to see in the Video Creation/Photo Editing tests, the 1066MHz FSB does absolutely nothing for performance here.

In the past, DivX encoding has seen reasonable performance increases due to a faster FSB and increased memory bandwidth. With the move to the 1066MHz FSB we seem to have hit a limit, as there's absolutely no performance improvement here either. It looks like it will take much higher clock speeds for the 1066MHz FSB to make a difference.

Games have also been areas where faster FSB frequencies have benefited Intel, but once again we see that the average performance increase is less than a percent. Starwars Battlefront shows the greatest increase in performance at 2.8% due to the 1066MHz FSB.

We weren't expecting to see much in the 3D rendering tests and the 1066MHz FSB did not disappoint with only a 0.74% average performance increase here.

Our final suite of tests are the professional applications tested by SPECviewperf 8. Here we see the largest overall gains provided by the 1066MHz FSB, with performance improvements approaching 5%, and average performance improvements approaching 3%. There's very little gain in compiling performance but in the realm of 3D professional application performance the 1066MHz FSB begins to show its worth. The gains here will only get better as clock speeds increase, so maybe the 1066MHz FSB will pay off for those running demanding enough applications to require a $1000+ 3.46EE CPU.