Computer does not boot with 4 gb installed

daudulus

Reputable
Mar 9, 2014
2
0
4,510
Originally I had 2 x Corsair PC2-6400 800 MHz 1 gb (4-4-4-12) RAM modules installed in my computer. Now I try to expand my RAM capacity with 2 x Corsair PC2-6400 800 MHz 1 gb (5-5-5-12) modules. I know it would have been better if I had bought additional RAM modules with the same timings as the existing modules but I still want to get it to work.

I´ve tried many configurations but I can only get my computer to boot up till 3 gb. As soon as I try 4 gb so including all modules in the memory slots the computer won´t boot. I tried both new modules individually to make sure none of them is malfunctioning. I´ve read many threads in this forum and tried several things such as setting the memory voltage to 2.1 V but nothing works. Probably I miss a small detail but there are just so many settings/combinations I can change in the BIOS that I´m not sure how to proceed. Does anyone have suggestions about what more I can try?

The motherboard of the computer is an ASUSTek P5B and the BIOS version 2104 is installed on it. Please let me know if you´d like to have more information about my computer specifications.
 

daudulus

Reputable
Mar 9, 2014
2
0
4,510
Thanks for your support.
However, I´ve already performed BIOS resets and I made sure timings are set to 5-5-5-12 or even slower. Thus if I understand correctly the modules can be incompatible even though a single 5-5-5-12 module can work together with two 4-4-4-12 modules?
 
yes you understand correctly. To be sure that the new sticks are not bad insert them and run memtest86+. this will test the memory to be sure there is not a bad stick. Ram can be very finicky when trying to mix kits. Example: You can run into problems buying 2 kits of ram being the same exact kits. Yes the chances are much higher that they will play together nicely but there can be compatibility issues.

even though you bought the same brand it does not guaranty the two kits will work together.