8GB Crashes PC

[Lfluxx]

Hey,
I've had an ongoing problem for a while now that whenever 8GB ram is installed into my computer it will crash on boot. I tried all the ram seperately to rule out that the ram was faulty and tested each slot too, all was ok. So i then tried with 2x2GB and 1x4GB as maybe the mobo was struggling to use 4Slots.. again it crashed with 8GB ram.
Please help D: My specs are..

I5 650 3.2Ghz
2x2GB Asint DDR3 1333 1x4GB Kingston DDR3 1333
Foxconn p55a motherboard

I can run 6GB fine, its just the 8gb that is the problem.

Thanks.

 

[hermz1337]

What version of windows are you using? Also, are the configuration of 8gb ram the same make and model sticks?

 

[Lfluxx]

Windows 7 64bit os, as far as i know all of the ram is pc3 10600 however 2 of the 3 sticks are asint and one is kingston, i can run the computer fine with the 4gb stick and one 2gb stick too its just adding the final one.

 

[hermz1337]

The CAS timings can be different even though they are the same speed as well as voltage. This could be your issue. Now from what you post it seems as though they are different size sticks you are using simultaneously, that can also lead to issues. I suggest only using the same make/model ram that are the same size together, they should then run in dual channel thus increasing performance over using different kinds even though it is greater capacity. So to put it simply, use the 2x2 asint ram, it will increase performance over using all 3 together. If you use all 3 together it can only run in single channel.

 

[RetiredChief]

^ +5. If Timing and voltages are the same for all sticks (Use CPUID CPU-Z to verify), then
May be loading the Bus freq down. Try bumping up the frontside bus voltage (try increasing by 0.05 v, if that works then fine, else try adding a 2nd 0.05 v (Should NOT have to go above 0.1 V from stock ), if that works leave it at that. Some lower -> midlevel motherboards are hard pressed to work with 4 sticks of ram.

 

[Lfluxx]

Hey, thanks for your replies. i read up about lowering the FSB from 13333 to 10600, any idea on how to do this? i was told that about the 4 slot thing before, then advised to get the 4gb stick, and in future i will try matching makes/models. Thanks.