What ram to get for an E8400?

Jul 24, 2008
Hey Guys,

I'm looking for ram for my E8400.

Been reading the forums and trying to understand things...

if I understand right the FSB of the 8400 is 333mhz.

how does typical 800Mhz DDR 2 ram tie into that?

Is there an advantage to getting 1000mhz ddr2 ram (333x3?)

I've seen recomendations that faster ram wins vs lower cas settings - does this apply?

I suppose I have 2 scenarios for the 8400 in mind...
scenario 1 - run it at stock speeds (333 FSB, 3ghz)
scenario 2 - overclock it (400FSB, 3.6 ghz)

Do either of these scenarios lend themselves better to one type of ram vs the other?
I could almost see doing PC1000 ram for the stock speed, but I don't understand the whole system well enough to know if this makes any sense...


Oct 25, 2006
i'm running 8 gigs of ocz reaper pc-8500 (ddr1066) with my intel 8400 cpu


Supreme [H]ardness
Jul 13, 2008
With original DDR memory, the speed of the ram was supposed to be equal to the processor. Hence, you had DDR 333 memory for standard PCs, and DDR 400 if you wanted to crank up the clocks.

Now DDR 2 means the speeds are doubled. So DDR 800 actually matches 400 MHz on the processor. Equivalent DDR 3 speed would be DDR 1200.

So, essentially, you want to determine how much you want to push it. The E8400 is 9x333. So, if you use DDR2 800 memory, a safe bet would be 9x400 which is 3.6GHz on your CPU. If you use DDR2 1000 memory, your tested memory clock to match your CPU would be 500, so your CPU, assuming you got a chip that can do it, would be able to handle 9x500, or 4.5GHz. Is that likely? No.

However, the advantage of using memory rated to go up to 500MHz(DDR2 1000) means you can downclock it to, say, 450MHz. 9x450 on the CPU would be 4.05GHz, and many people have achieved that with E8400s. You could do the same with 400MHz memory (DDR2 800) but you would have to overclock, and there is no guarantee that the memory will handle the overclock stably. So, what you're doing is purchasing a guarantee of speed. It's sort of like buying one of the extreme versions of an intel processor. Its higher multiplier guarantees higher overclocks, but you're paying a premium for it.

However, memory is cheap as hell, so go wild. :D
May 10, 2008
I'm planning on running my e8400 with some OCZ Sli-Ready 1066MHz ram. This thing is gonna kick.
Jul 17, 2004
If I don't overclock and leave the E8400 FSB at 333mhz, does that mean I would see no difference between ddr1066 and ddr800 ram?

Also, what mobo would you recommend? I've seen boards with a memory standard of 1066, does that just mean it supports up to ddr1066, meaning that anything less is also fine?

Edit: I'm retarded. There was a thread on the front page asking the exact same question.