I'm looking to upgrade the RAM in my P4T533-C. Can I put 2 chips
of PC1066 (256MB each) in the same board with 2 chips of PC800 (512MB
each), for a total of 1.5GB of memory?
If they won't mix, would I be better off going for 2 GB of PC800
RAM or 1 GB of PC1066 RAM?
You *should* be able to mix, but there are never any guarantees. The
rimms need to be properly paired up, so be certain to get the
banks/channels installed properly. There are only two proper ways that
the memory can be installed (presumably one of these two configurations is
'optimal' - not clear which that will be), but 6 different permutations
exist; thus the need for concern. You might want to try and find out if
there are recommendations as to size/speed in terms of which bank uses
which pair (does slower rimm pair go in RIMMA1/B1, smaller?) - apparently
there must be _some_ reason configuration a) is preferred to b) in the
manual...
Essentially what should happen is that once the memory has been installed
correctly, it will all be run at the lower speed (PC800). Settings should
be autodetected properly, given the BIOS has been programmed completely
and correctly - but this can be manually bypassed in the BIOS settings if
needed/desired. *MOST* PC1066 memory should run at PC800, and depending
on your setup you may be able to meet somewhere in-between (Like the guy
running 2GB PC800 @ 156/PC940, or myself running 512MB PC800 @ 120/PC960).
If memtest suggests some marginal errors in test 5, perhaps swap RIMMB1
with RIMMB2, and swap RIMMA1 with RIMMA2 - then try again...
It's not clear how much memory you need, or what your speed requirements
are, so can't recommend any one of the 3 options. Certainly the mixing
involves the most risk, and essentially leaves you with 512MB less memory
than the much simpler 2GB PC800 implementation at the same speed (but
obviously it's much less $$$expensive$$$)... I'm not familiar with the
RDRAM cost differential from PC800 to PC1024, but it seems to me it should
be about nil these days - I'd recommend holding out for PC1024 512MB rimms
if they aren't that much more $$$.
--
We HAVE been at war with Iraq for 14 years now, bombing their
country on at least a weekly basis.
"U.S.-led sanctions have killed over a million Iraqi citizens,
according to UN studies" - James Jennings
3,000+ innocent Iraqi civilian casualties can't be "wrong"...
