Intel Pentium III E FC-PGA (Socket-370)

With every processor release, Intel also releases a set of guidelines that motherboard manufacturers should follow so that their products will be compatible with the new processor. Part of these guidelines are the design specifications that address what voltage regulator module (VRM) implementation needs to be placed on the motherboard. When the Pentium II was released, motherboard manufacturers had to follow the VRM 8.1 guidelines and upon the release of the Celeron processor the VRM 8.2 specification had to be adhered to. Intel’s higher end CPUs and multiprocessor systems also require a different VRM specification -- VRM 8.3 for all Xeon motherboards and optional for dual processor Slot-1 Motherboards. How does this apply to the FC-PGA running in older motherboards?

Each VRM specification is generally backwards compatible as long as it applies to CPUs of a similar family. For example, a motherboard with a VRM that meets the 8.2 guidelines will have no problem suiting an original Pentium II CPU that required the 8.1 specification. Obviously, this compatibility doesn’t work both ways (Intel can’t predict the voltage requirements of future processors) and thus a Pentium III CPU won’t work in a motherboard that only meets the VRM 8.1 specification. Make sense? Well, guess what the FC-PGA requires? Compliance with the latest VRM 8.4 guidelines, which currently, no Socket-370 BX motherboard officially supports. This means that all the users that picked up ABIT’s BP6 with hopes of upgrading to dual Pentium III E processors are out of luck.

We also tried the FC-PGA in our Apollo Pro 133A based Tyan S1894 motherboard, to no avail as well; it seems as if even the latest motherboards do not support the VRM 8.4 specification.

The FC-PGA has not changed the Socket-370 Voltage Identification Definition (VID) pinout that was originally defined with the Celeron. This means that the VID pins on the FC-PGA correspond to the same settings on the Socket-370 Celeron. If this weren’t the case, then older Celeron CPUs wouldn’t be able to work on newer Socket-370 motherboards that are FC-PGA compatible.

We’re just going to have to accept the fact that our beloved Socket-370 motherboards do not support the new FC-PGA. This does not mean that future Socket-370 motherboards won’t support it. Currently, all i810E motherboards support the FC-PGA and are in full compliance with the VRM 8.4 guidelines. For those of you not familiar with the chipset, the i810E is the successor to the i810, adding support for the 133MHz FSB and an optional 133MHz Display Cache. The i810E features Intel’s integrated i752 graphics processor, which is no where near a good gaming solution by today’s standards, scaring many potential FC-PGA owners away from the platform. But there is hope.

It is entirely possible that a motherboard manufacturer could manufacture a Socket-370 BX motherboard that meets the VRM 8.4 design guidelines and it would be fully compatible with the FC-PGA (as long as it met the other requirements). But for now, it’s i810E or bust for the FC-PGA. Very disappointing.