Memory upgrade worth it (been given some slower ram for free)?

woffle99

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Nov 4, 2007
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Bit of a poser this one so I'd be grateful for advice. I currently have a machine with 2GB of DDR2 667 memory (2 x 1GB matching pair). My brother has just given me 2GB of DDR2 400 memory (again 2 x 1GB matching pair).

My motherboard will take this speed and has four slots for Ram so in that sense it's not a problem - in fact I've put it in and it seems to be fine - but the memory is obviously rated slower than the stuff I already have. Will it slow the machine down? I ran the (admittedly limited) vista rating utility on my machine and the rating for memory didn't change (was 5.2 and is still 5.2).

From what I've read, all the memory will now run at the DDR2-400 speed (is that right though - they're in two different banks and both run as dual channel). If so, is it better to have 4GB of slower memory or 2GB of faster memory? I run both Vista and XP on this machine in a dual boot. I use XP exclusively for games and Vista for the odd game but mostly non-gamey stuff including playing around with virtual machines and the odd bit of video editing. All other components are quite speedy (Core2Duo 6400, Geforce 8800GTS 320mb) so will the reduced memory speed really make a noticeable difference?

Any and all advice welcome.

Thanks.
 

woffle99

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Thanks for the reply akhilles. I'm not a great one for making changes to the bios - I usually only do so when my machines are getting a bit aged and can do with a bit of a push to help them with some of the newer games, and I'm not there yet with this machine. Also my mobo is an Asus P5NE-SLI which I've discovered can be very picky about memory types and memory timings so unless this memory combo turns out to be unstable I'll probably leave alone for the time being.
 

woffle99

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Ok slight mistake in my original post - it's actually 4200 memory (533 speed) and not 3200 memory (400 speed), so only one step down the ladder from my original 5300 (667 speed) sticks rather than two.

Not sure how much difference that makes though in terms of speed.
 

albenza

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Aug 18, 2007
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It shouldnt matter much since you FSB on that processor is 1066, meaning the maximum frequency will be 266MHZ anyhow. Wheter you use pc-6400, 5300 or 4200 RAM your CPU will still run at 266MHz. In this case 1:1 ratio which is optimal.

Correct me if I'm wrong...

However, if you at some point wish to overclock it might be beneficial to only run the fastest RAM.
 
Yes, I agree with albenza.
You can run the memory at 1:1.
With a 32-bit system you will not see the full 4 GB, you will see about 3.5 GB. That's a limitation of 32 bit systems.
If you have a 64 bit system, this won't apply.