It would be better to buy just 2 sticks of 1 gig memory rather that the 4
sticks of 512.
AMD on die memory controllers don't handle all 4 slots filled very well.
Ken'
Just saw this post. I'm getting ready, or at least was, to buy two more 512
modules for my Intel4 based system on a P4C800 Deluxe motherboard. I currently
have two 512 modules onboard. Are you aware of any problems with that
combination running four 512 modules? I posted elsewhere on this board
concerning buying the two additional modules 17 months after I built
the system and trying to match what's already in the machine. Thanks.[/QUOTE]
I've run two Ballistix PC3200 512MB double sided DIMMs and also four
Ballistix PC3200 512MB double sided DIMMs and had no problem with
either configuration. All settings remained the same (including
PAT enabled).
With respect to the 1T versus 2T command rate thing, the Intel chipsets
don't mention this parameter in their data sheets, and I saw a comment
on Xbitlabs, that the chipsets always use 2T command rate timing. It is
pretty hard to prove it one way or another, short of using a scope or
logic analyser.
In any case, I wouldn't be overly concerned with fitting another
two DIMMs. Sure, if you select some generic CAS3 DIMMs that are
half the price of other modules, you might end up with bad RAM.
But, as a rule, when compared to other motherboard brands, Asus
usually does a pretty good job on RAM compatibility. In some cases,
if you extract all the modules from your BIOS file, you'll see
part numbers for a certain number of RAM in there, implying that
Asus applies special conditions for some RAM. That is presumably
because the SPD on the DIMM is known to lie about the RAM
parameters.
When you get your new matched pair of DIMMs, test them separately
first, to make sure there are no problems with the new RAM by
themselves. Memtest86+ and Prime95 are good programs to use for
that purpose (a couple of passes error free with Memtest86+ is
enough, before booting to Windpws and doing the real test with
Prime95).
In terms of best strategy, if you are overclocking, two DIMMs in
dual channel mode gives the best possibility of overclocking. I
wouldn't use 4x512MB if trying to reach DDR500 (you'd be lucky
to hit DDR440 with four double sided modules). In that case 2x1GB
is the way to go, just like with Athlon64. At ordinary memory
speeds (PC3200 running at DDR400), either two or four sticks will
be fine on 875P, whereas on Athlon64, four sticks might require
2T command rate, and take a 15% memory bandwidth penalty compared
to running with two sticks at 1T command rate.
HTH,
Paul
