NVIDIA nForce2 Preview

Dynamic Adaptive Speculative Pre-Processor – Take 2

The nForce2 IGP/SPP also has what NVIDIA is calling a “2nd generation” Dynamic Adaptive Speculative Pre-Processor (DASP). There’s not much information on NVIDIA’s 2nd generation DASP so we’re not able to quantify the improvements NVIDIA made over the original nForce.

As you will remember from our nForce Computer 2001 Preview, NVIDIA’s DASP acts much like the hardware prefetch logic found on Pentium 4s and Athlon XP processors. The logic makes educated guesses about future memory accesses based on where in main memory data was recently accessed from as well as how frequently it was accessed in the past. After making these guesses the logic pre-fetches the data it thinks will be requested into its buffer; should the data be required by the CPU then access latency is reduced by tens of nanoseconds by not requiring a memory access. If the data is never requested by the CPU then it will eventually get replaced in the DASP buffer by other pre-fetched data without incurring a performance hit or gain.

With the original nForce, NVIDIA’s DASP increased performance in synthetic benchmarks by up to 30% and applications such as Adobe Premier and Windows Media Encoder saw a 5 – 10% boost. However, the inclusion of NVIDIA’s DASP logic was not enough to give the nForce chipset a significant performance advantage over the competition. The tuned memory controllers and pre-existing buffers in VIA’s KT266A chipset proved to be more than enough to remain competitive with nForce, and the KT333 even outperformed it. We remain skeptical as to how much of a performance boost this second generation DASP offers but it’s worth mentioning that it is still in there.