At 17:59 01-06-98 -0600, Drew wrote:
>A while back there was a discourse on how much memory a PII could cache.
>I think that we agreed on up to 512K, which is correct.  I just read
>...that Intel has overcome that limitation on the PII-350 and 400's.

Yes. Not only do the 350 and 400 MHZ Pentium II CPUs run at 100 MHZ
(instead of 66 MHZ) system clock speeds, multiples of which give the
CPU clock speeds, but...

According to the "Pentium II Processor at 350 MHz and 400 MHZ Datasheet",
<ftp://download.intel.com/design/PentiumII/datashts/24365701.pdf>, the
350 and 400 MHZ Pentium II CPUs are now available "with integrated 512
KB unified, nonblocking, level two cache [so that]...memory is cacheable
for up to 4 GB of addressable memory space...Please refer to the Intel
Specification Update documents S-spec number to determine the
cacheability for a given processor."

Maybe the key word is "nonblocking". Anymore, at least for now, no more
limitation on cacheability. But the other limitations remain: Data is
transferred from L2 to the CPU at only half the CPU clock speed and you
can only use two Pentium II CPUs in a SMP system.

Regards,
Bill