First off, did you notice the omission of the Celeron from the list of supported CPUs for the VC820? It's not a mistake, this is a high-end platform, and to work properly Intel feels that it needs a CPU that can operate at a 100MHz front side bus or higher.

We tried booting up a Celeron in both Slot-1 and PPGA formats (using a Slotket converter) to no avail, the VC820 didn't even blink.

Luckily any Pentium II or Pentium III CPU can be used with the VC820 mainboard, it automatically detects what model is plugged into it at boot up and configures its voltage and clock settings appropriately. This does mean though that the VC820 doesn't allow the manual control of the CPU's speed, so overclocking on this particular board isn't possible.

In regards to memory support, as we mentioned previously it was thought that up to three RIMM modules may be used on a PC desktop motherboard while occupied with RDRAM, and the version of the Intel VC820 we posses follows this format.

Two RIMM slots seems more realistic now in order for the i820's launch time frame to be achieved soon while eliminating the data problem that caused the delay, again the maximum amount of RDRAM potential on the revised VC820 will still be 512MB.

We're surprised somewhat that Intel has chosen to introduce its flagship desktop mainboard with less total memory support than their previous 440BX product line currently offers. We doubt however that many users would have had the need (or budget) to have gone beyond 512MB of RDRAM in their desktop i820 systems anyway, but we still would like more memory options on future i820 mainboards from third party vendors.

As indicated on the spec sheet, there are three types of RDRAM that are available for RDRAM-based PCs.

PC600, PC700, and PC800 are the Intel given names for the models, and they operate on a 300, 356, and 400MHz bus speed respectively.

The RDRAM RIMM modules conform to the standard DIMM form factor, but they aren't pin-compatible. The RIMM architecture is based on the electrical requirements of the Direct Rambus Channel, a high-speed bus operating at a clock rate of 400MHz which enables a data speed of 800MHz as data is clocked on both clock edges. A two byte-wide data channel is used in conjunction with the high clock speed, resulting in a peak data transfer rate of 1,600MB/sec.