# [SOLVED] Compatible RAM? Upgrading from 4GB to 8GB



## lambchop123 (May 2, 2007)

Hi All,

I'll do my best to give a complete explanation although am happy to provide more info if needed.

My computer is getting bogged down and slow. It's a custom PC which I bought around 4 years ago. I don't want to upgrade it completely - only give it a good boost to last me another couple of years until I replace it/switch to cloud computing/migrate to the mothership.

As far an CPU-Z can tell me, my specs are:

Motherboard: Asus P5KC
Memory currently installed: 2 modules x Corsair PC2-6400 DDR2
CPU: Intel Core 2 Quad Q6600 @ 2.40GHz. Socket 775 LGA. Rated FSB ~10663MHz. Bus Speed ~266MHz.

Below is a link to the Asus website for the motherboard:
ASUS - Motherboards- ASUS P5KC

... and also to the P5KC Memory QVL list:
ASUS - Motherboards- ASUS P5KC

I've done my best to understand the issue via Googling and the Crucial website. The P5KC motherboard supports DDR3 RAM and appears to be no more expensive than DDR2. Therefore, I have found the following two deals which appear to be suitable:

4GB kit (2GBx2), 240-pin DIMM, DDR3 PC3-8500 memory module (I would purchase two lots of this):
4GB kit (2GBx2), 240-pin DIMM, DDR3 PC3-8500 upgrades for ASUS P5KC Motherboard, CT725341 from Crucial.com

Corsair Memory XMS3 Classic 8GB DDR3 1333 Mhz CAS 9 Quad Channel Desktop:
Corsair Memory XMS3 Classic 8GB DDR3 1333 Mhz CAS 9 Quad Channel Desktop - CMX8GX3M4B1333C9 - Scan.co.uk

I'm a gamer but not hardcore so matching up the exact FSB:Memory clock ratio isn't important to me. I am more interested in cost but, of course, if it isn't too great a leap to choose other RAM modules with more suitable clock speeds, I will do just that.

I would be grateful if someone could advise if those two deals will work before I invest or propose more suitable options.

Thank you kindly!


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## Tyree (May 10, 2009)

*Re: Compatible RAM? Upgrading from 4GB to 8GB*

Your better option is to remove the present RAM and use a 2x4GB matched pair of 1066GHz. G.Skill & Corsair are good brands.


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## gcavan (Aug 13, 2009)

*Re: Compatible RAM? Upgrading from 4GB to 8GB*

Note that unless you have a 64 bit version of your operating system installed, only the first 3.25 GB or so of memory will be recognized.


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## Tyree (May 10, 2009)

*Re: Compatible RAM? Upgrading from 4GB to 8GB*

Good point^
If you're using a 32Bit OS you might as well stay with your 2x2GB. Few games/apps can utilize over 3GB anyway but we recommend 8GB (2x4) for new builds primarily because RAM is so cheap.


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## lambchop123 (May 2, 2007)

*Re: Compatible RAM? Upgrading from 4GB to 8GB*

Hi guys,

Thanks for the quick responses. I will certainly remove the RAM I have installed currently. I have Windows 7 64-bit so I can use the extra RAM.

Before I buy the RAM, can you say if everything else would work? I've heard that you can buy RAM with the wrong number of pins, incompatible with that type of motherboard etc.


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## gcavan (Aug 13, 2009)

*Re: Compatible RAM? Upgrading from 4GB to 8GB*

I must apologize for not noticing this earlier. Your board is sort of a 'special case' in that it supports both DDR2 and DDR3 memory (though not at the same time).

Your board will only accept memory modules with capacity of up to 2GB each which means you could install up to 8GB (4 x 2GB) of DDR2 memory but only 4 GB (2 x 2GB) of DDR3. 

So in referring back to your post#1, the second link (Corsair 4 x 2GB kit from scan.co.uk) will not be suitable as you could only install two of the DIMMs.


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## Tyree (May 10, 2009)

*Re: Compatible RAM? Upgrading from 4GB to 8GB*

Good catch and advice from gcavan.


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## lambchop123 (May 2, 2007)

*Re: Compatible RAM? Upgrading from 4GB to 8GB*

Thank you gcavan and thank you all for your helpful responses. I was literally on the verge of placing an order for some plain old DDR2 PC2-6400 RAM to keep my PC going for hopefully another year or two before it gives up completely before I reconsidered. I thought: Instead of paying £50 now and having a slightly faster but essentially low powered PC, why not put that £50 towards a better PC in the future?

I've gone with that option and might try my hand at building it myself one day. In which case I'll be seeing you all again. I learned a few things through this post in any case.

For those interested, I was about to get this RAM: Corsair Memory XMS2 4GB DDR2 PC2-6400 (800) Dual Channel Desktop - TWIN2X4096-6400C5C - Scan.co.uk

Thanks again.


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## Tyree (May 10, 2009)

When you decide to build your own PC, use our suggested build list for ideas: http://www.techsupportforum.com/for...evised-2012-and-updated-regularly-448272.html


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