Sneak Peek at 800MHz FSB Performance

800MHz FSB Chipsets

We've already discussed the 875 and 865 chipsets in a decent amount of detail in our IDF coverage, so here's a quick recap:

The focus of 2003 will obviously shift to the new 875 and 865 chipsets, but motherboard manufacturers also have other options to look at for 800MHz FSB support.

The 845PE chipset isn't dead yet, several motherboards makers (including a few top tier manufacturers) plan on releasing new 845PE motherboards that have been validated to support 800MHz FSB Pentium 4 processors. These 800MHz FSB 845PE motherboards will basically be a cheap way of getting 800MHz FSB support, but obviously won't perform nearly as well as the 875 and 865 solutions.

At the moment, SiS' 655 chipset has taken away Intel's 2 year plus long performance reign in the Pentium 4 market, though only while operating at the fastest memory timings and at the highest supported memory speed (dual channel DDR400 mode). Nonetheless, this is quite impressive, especially since SiS wasn't considered a real player in the CPU chipset market not too long ago.

SiS is no less competitive when it comes to supporting 800MHz FSB P4 processors. As we just mentioned, we have run extensive tests on several SiS 655 motherboards, and much to our dismay only one of them is able to reliably overclock to 800MHz FSB in dual channel DDR mode. MSI, Gigabyte and ASUS confirmed that their SiS 655 motherboards will not officially support 800MHz FSB processors at any point in time, via a BIOS update or otherwise.

But what motherboard makers plan on doing instead is releasing boards based on the SiS 655FX and SiS 648FX chipsets, which are validated for 800MHz FSB operation. The 655FX is simply an updated version of 655 that has been debugged and validated for 800MHz FSB P4 processors, just as the 648FX is an updated version of 648 that has been debugged and validated for 800MHz FSB P4 processors. Most motherboard makers expect mass production of their SiS 655FX motherboards to begin sometime in late April or early May; in other words just after Intel's 875 launch but before the 865 launch. SiS 648FX motherboards are expected to start trickling into the retail channel sometime later this month.