PC800 RDRAM* memory is offered with two different specifications, PC800-40 and PC800-45, both of which run at the same frequency and have identical bandwidth, but have a subtle difference in internal timing.

The Intel® 850E chipset is designed to support only PC800-40 memory when running at 533 MHz system bus. The Intel 850E chipset supports both PC800-40 and PC800-45 memory while running at 400 MHz system bus.

If you plan to build systems based on D850EMV2 and/or D850EMD2 boards with 533 MHz system bus Intel® Pentium® 4 Processors, PC800-40 must be used. Please work with your local memory suppliers to stock sufficient PC800-40 for use with 533 MHz system bus Intel® Pentium® 4 Processors. Please continue to utilize validated PC800-45 memory for systems based on 400 MHz system bus Pentium® 4 Processors.

The following Intel Web site reflects a list of RIMM manufacturers and PC800-40 part numbers. This site will be updated on a regular basis as new PC800-40 part numbers are validated:
http://developer.intel.com/technology/memory/
or
The tested memory list for Intel Desktop Boards D850EMV2 and D850EMD2 will be available beginning May 6, 2002 at:
http://developer.intel.com/design/motherbd/mv2/mv2_mem.htm