RAM upgrade


I have a user who wants to upgrade their CPU to 8GB of RAM. Currently, they only use 3GB of RAM (3 of 4 RAM slots have been occupied).

The RAM type is DDR3, and the DRAM Frequency is 531.4 MHz.

Is it possible to use 4GB DDR3 RAM 1333 MHz to occupy 2 of the slots??

Please advise.

i found that udgrade from 2gig too 3 gig slowed down my system but i put it down too the motherboard poor quality but hey its been working for 5yrs so far :) on 2gig
I can't play 720p or 1080p hd videos smoothly on YouTube. Do I need more ram to better that performance, or does ram have nothing to do with it and do I need a better video or graphics card? If ram is the case, how much is usually needed for a smooth playback of hd videos?
@spidersilva: read this

or here is the google search page for this issue you might read several threads to see if any match your system and it appears to be cpu not graphics card
Yup, it's my cpu. I only have 991 MHz processor lol. I would need 2.4 GHz processor or equivalent and 384 MB of ram and 64 MB video card to play 720p. I would need a 3.0 GHz processor or equivalent and 512 MB of ram and 128 MB video card to play 1080p. So would you put a faster cpu or would it just be better to buy a new computer?
do you watch a lot of videos??

changing the processor would require reactivation if the processor is an integral part of the motherboard, as the motherboard is tied to the product key on an OEM pc, is your pc oem?? ie. dell, hp, acer.. etc.??

If all else is working on your pc, and you still like xp, you might want to get a new cpu, but make sure you get one from your pc manufacturer , then it will be compatible with your pc.

I have a dell dimension 3000 desktop with a pentium 4 cpu 2.8gh. and do not have much problem watching videos on youtube.
You have a cpu in the GHz which is why you have no problem with hd youtube videos, MHz won't do it. I have an hp but I think I'll just get a new faster and better computer but another hp, hp computers seem good.
okay, HP's are okay, but I prefer dell's, as hp sometimes requires certain downloads from their website to install other things, but it is just my preference, win 7 is going to be obsolete soon also, so I would not get one with win7, that leaves mac or win 8.1