Windows 4Gb limit Question

estebanrey · 23 Sep 2009 at 09:55

Hi all, I'm gonna wait til next year to build a new system, when Windows 7 and DX11 are mainstream and, more importantly, I'll have the cash to do it. Until then I'm looking at one final max out of my P4 system.

Anyway, I'm currently running

Asus P5AD2-E Premium
Intel P4 3.0GHz
2.5GB of mixed DDR2 RAM
ATi X1950 512mb

..now I'm looking at the replacing the built up and mix and match RAM I currently have for 4 Crucial Balistix PC2-8500 1066MHz units and swapping my X1950 (fan has got really noisy) with an HD49XX 1GB card.

Now, as I understand it Windows XP 32 can only recognise and use 4GB total memory and with the above upgrades I will have 5GB (4 in RAM and 1 in VRAM). So my question is should I just buy 3 sticks of the Crucial RAM as the 4th would be wasted?

The confusion for me comes when I get told that RAM works best in matched pairs. Therefore if I only buy/install 3GB one of those wouldn't be in a "matched pair" and thus would I lose performance.

Thanks in advance for any advice!!

estebanrey · 23 Sep 2009 at 10:07

Thanks 95thrifles although I will have to get 4 x 1gb as my Mobo can't handle 2gb sticks

** oh and with the 58XX coming out today I might wait a couple of weeks for the 48XX as prices should fall right?

estebanrey · 23 Sep 2009 at 12:03

SMAndy said:
As a tip, if you're planning on overclocking, you may find that your memory won't clock as high if you're filling all 4 RAM slots. I don't know why, but it doesn't like 1T mode as much if you've got more than 2 sticks.

Ahh thanks, I have always overclocked my system but mainly only to make it capable of running the games I play. All I need it to be capable of for the time being is running BF2 and Pro Evo 2010 which by today's standards are nothing so hopefully I won't need to OC at all with my new bits.

So the concensus is I pay the extra 1gb stick (despite the fact it won't be used) due to the benefits of dual channel?

estebanrey · 23 Sep 2009 at 21:44

HazardO said:
You definitely want to run your memory as dual channel, this may be possible with 2x 1G and 2x512M (1.5G in each channel), but you might not be making much of a saving, and 512M sticks aren't that easy to get hold of anymore.

Talk of hard to get hold of, OcUK doesn't sell any 1Gb sticks of 8500/1066Mhz.

Another question then, is it even worth me going for the highest or should I just go with the PC2-6400/800Mhz? My mobo does support a 1066 FSB but is getting that high only with overclocking?

To be fair seeing as I can get 1Gb sticks that are 8500s for 15 quid there's not much of a saving.

Final noob question, does buying 'matched pairs' mean buying a 'kit' as I was just going to buy 4 stick seperately. I thought just getting ones that are the same spec was all that was advised but I've heard some since say they should be from the same production run (i.e bought in a kit)?

Thanks again guys