One of the most common problems that can cause instability in a system, whether it is overclocked or not, is NOT making sure that the RAM voltage (VDIMM) and timings are manually set.

DDR2 has a default voltage of 1.8v as outlined in the JEDEC spec which can be viewed here.

Most high performance memory modules need voltages that are higher than the 1.8v DDR2 standard.

So, you put your new DDR2 in your PC, boot up and you are getting BSODs, random restarts and other general nastiness, and now we know why don't we?

Yes!, it's because your new RAM isn't getting enough voltage to run at the speed that it was intended.

But why not?

Well, because your motherboard, by default will give the RAM 1.8v (as per the JEDEC spec above). This is completely normal, and most up to date systems should boot at 1.8v, even with performance RAM that requires 2.*v.

As soon as you start your PC for the first time, go straight to the BIOS and set the RAM timings and voltages. This can help you avoid a lot of problems later.

If you aren't sure what the timings and voltages should be, look on the sticks themselves, or check the manufacturers website.

Another frequently asked question about RAM, is...

Why does my PC2-8500 RAM show up as PC2-6400?

It's that JEDEC spec again! Currently there isnt a JEDEC spec for PC2-8500, so the manufacturers use the next fastest official JEDEC spec for DDR2, which is PC2-6400 (DDR2-800).

This just means that your RAM will always default to 800Mhz instead of 1066Mhz when you clear the CMOS or update the BIOS. Again, it is just a case of setting it manually (see pic below.).



This is the way to do it if you are NOT overclocking your CPU. If you are overclocking the CPU, please see the info in the overclocking guide.

Some of this info is already in the guides, but this will hopefully be of use to the people that arent overclocking.

If anyone wants to add anything, or I've forgotten anything, just let me know.

Hopefully this will help a lot of the people that seem to be getting stuck with this recently

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