NationStates Jolt Archive

Ok, I'm having a problem with my computer's RAM: I have 512 mb of DDR400 Corsair XMS memory and a motherboard that supports DDR400...but for some reason that I can't explain the memory is running at 166 mhz instead of the 400 that it should be capable of. Does anyone know why this could be?

I recently bought myself a laptop for college. I know how confusing computers can be. When the guy talked about mHz and MBs and GB, it went right over my head. As far as I can tell you, the processors may not be properly installed, which is why your computer is running slower than 400. You probably should call up a computer store, such as Circuit City, and tell them your problem.

What processor are you using? The memory bandwidth on the processor may be the cause. I'm using a Athlon 1800+ on my board, it's specified to run at 133 MHz(266 MHz Dual Channel) on the FSB(Frontside Bus). However, my motherboard supports up to 200MHz(400MHz Dual Channel, what you want).

The processor is an Athlon 2800+ with a FSB of 333 mhz.

So as near as I can tell there's no reason why it ought to be running at such a slow speed.

Blame marketing for the confusion. Your ram does actually run at 166MHz, but since it's DDR it's effectively acting as if it was really 333MHz. Your DDR400 ram will run as if it was clocked at 400MHz, but you need to adjust your FSB clockspeed to 200MHz for that to happen and/or get a processor that supports a 200MHz FSB.

If you're running dual channel on the motherboard as well, you should use at least 2 sticks of RAM. So you can buy another stick of 512MB, or sell the stick and buy two 256MBs. Both solutions will end up doubling the memory bandwidth.

I can't guarantee the safety of your CPU, but you can still utilize your RAM to the fullest extent on this CPU. Overclock your FSB to 200MHz and decrease the multiplier on your CPU to the point where it'd run somewhere close to 2250MHz (default speed). Setting the multiplier to 11x would generate a reasonable 2200MHz(11 x FSB speed) with an increased memory bandwidth of 400MHz. This may require additional cooling to run safely.

I hope this helps explain a little.

Someone correct me if I'm factually wrong.