Adding RAM - Will this work?

Well I just built my computer a few weeks ago with 2GB of RAM and was thinking of adding 2 more. Just wondering if these two would be compatible or would I see any performance issues?

Currently:

Corsair XMS2 TWIN2X2048-6400C4 Matched Pairs 2GB kit (2x1GB) PC6400 DDR2-800 CL 4-4-4-12 240-pin Dual Channel Memory

Looking to add:
OCZ (OCZ2P800R22GK) DDR2 PC2-6400 800MHz Platinum XTC Revision 2 2GB (2x1024MB) 4-4-4-15 Dual Channel Kit

I realize the only difference is the one timing (12 vs. 15), I just have no idea what that means if anyone could spread some light on it.

Only thing you need to worry about is that it's PC6400-800...the CAS rating usually doesn't matter unless your MB doesn't support it. Also, if you are a XP user, like me, and have 4 gigs of ram, Windows will only recognize 3.25 gigs. If you use Vista (yuke), then it will recognize the whole 4 gigs.

Good luck.

The timings will go together and your computer should automatically balance them for you. It will be fine, provided you have Vista to take advantage of the full 4 GB like Boomslang mentioned.

Ya I have XP....but 3.25 is better than 2 and I'm getting the second 2GB for $30 so might as well right...

make sure when you place them on the board you put em in the right spots. Two of the same type in the same coloured slots. Otherwise it wont preform as well.

Ok awesome thanks for the help everyone

You're only going to see the full 4gig if you're on Vista 64. Vista 32 has the same RAM limitations as XP 32.

Ok so I have an Asus M3A MoBo.....There is no OCZ memory listed on the QVL (Qualified vendors list). Is there still a possibility of the memory working or should I not even bother?

No reason it shouldn't work, it's all standards-based. Asus most likely has marketing/business partners that get preferred deals, thus the "qualifications."

Dornie is right on both accounts.
Both XP and Vista 32 bit can only recognize 3.5Gb including video memory.
However the 64 bit versions are capable of accessing over a TB of memory (even though current motherboards do not generally support more than 8GB)

Fregarum wrote:Dornie is right on both accounts.
Both XP and Vista 32 bit can only recognize 3.5Gb including video memory.
However the 64 bit versions are capable of accessing over a TB of memory (even though current motherboards do not generally support more than 8GB)

Humm i have an extra gig of memory coming in today which would bring my ram up to 3 gig (2x512 and i have 2x1gig in right now) and a 8800GT with 512mb, this would theoretically put me over the 3.5 gigs by like 36mb or so. Should i just not add the extra gig?

Dantos, having 3 gig of system memory will definitely help you out. I would still go for it. If you were upgrading to 4gb, I would probably advise you differently as an entire gb would be wasted.

Bullarky wrote:Dantos, having 3 gig of system memory will definitely help you out. I would still go for it. If you were upgrading to 4gb, I would probably advise you differently as an entire gb would be wasted.

I was just worried about wasting video memory, thanks

Dantos, your video memory wont be affected...

Your video card's memory is not an issue when dealing with overall system memory. I think many people have a less than clear view of how the system and OS allocates memory.

Without getting too technical...Window's 32bit OS, the way it is written can only map to 4gb of memory. There are ways around this, but out of the box, it can only map to 4gb of memory. So why can't it see all 4gb of memory? Well that all depends on your hardware set up. Motherboards, chipsets, and bios all play to this theoretical 3.5gb limit everyone is talking about. The fact that your video card has 512mb is just coincidence and has nothing to do with the 3.5 some people see. When the system boots, bios takes a chunk of memory, then the PCI gets the next chunk of memory. Now your Motherboard (chipset more specifically) will determine how much addressable memory is taken away from the OS. So the spectrum of memory most people see under normal XP is anywhere from 3.1 gb to 3.7gb (give or take).

So just to reiterate... The fact that you are running a 512meg video card has little affect on the memory allocation of the OS. So you will not be wasting any memory and in fact you could probably still benefit from extra 512mb of memory.

I hope I didn't confuse you more...

no, thanks alot. Im not to good when it comes to the core of a computer like BIOS and whatnot. I just know what stuff goes in what slot and general computer maintainence stuff.