NVIDIA's nForce 420/220: It's finally here

The Effects of DASP on Palomino

A big question we asked ourselves when we were first introduced to nForce's built-in prefetching logic (DASP) is how it would complement (if at all) the data prefetch in AMD's Palomino core.  In order to test this we chose a 1.2GHz Athlon processor and compared it to a 1.2GHz Athlon MP (Palomino core) on both the KT266A and nForce 420-D platforms.  In theory, the performance improvement each platform gets from moving to the Athlon MP should be identical since all other variables are held constant.  But if nForce's DASP indeed removes some of the benefit of the Palomino's data prefetch then the performance improvements shouldn't be identical.

Quake III Arena ended up being the perfect test for this as the KT266A clearly showed that it benefited more from the Thunderbird > Palomino transition than the nForce.  The only real explanation is that the IGP's DASP removes some of the usefulness of data prefetch provided by the Palomino core. 

It is also worth noting that these results are not visible in all benchmarks, Quake III Arena is a special case because data prefetch improves performance under the game so much already.