As for performance there's currently one Pentium 4 chipset that holds the performance crown and not surprisingly this is still Intel's i850 with the SiS' 645 chipset and DDR 333 not trailing too far behind. Although the performance difference between the two isn't large, we're talking a few percent here, it is good to see that SiS is indeed showing that 3rd party doesn't always mean under performing, just as with their SiS 745 AMD Athlon chipset this chipset does equally well.

Fig 1. SYSmark 2001 performance, all DDR SDRAM chipsets are within a few percent of one another.

Fig 2. Quake 3 Arena, demo001 at 640x480 brings out some differences but nothing noteworthy.

Overall we see that the i845D is able to offer significantly better performance than the i845 but it is not the best performing DDR SDRAM Pentium 4 chipset available. SiS’ 635 chipset is clearly the best performing DDR SDRAM chipset for Pentium 4. Naturally part of this performance is due to the DDR 333 support, but as the i845D has been worked on for quite some time, why didn’t Intel simply include DDR 333 support in their i845D chipset too? The answer is simple and I already mentioned it a few paragraphs ago, ATA133, DDR 333 and 533MHz FSB will be reserved for the i845G chipset and we're at least six months away from the i845G's introduction.