Built New PC: DDR 400 running at 333 - why?

[kevotron]

I just built a new machine with an MSI 865PE Neo2-V Motherboard using a Pentium 4 2.40A Ghz processor with a 533mhz system bus -- this motherboard says it supports DDR 400, but when I check it in BIOS or with Sisoft Sandra it says it running at 333mhz. Is there something glaringly obvious I missed? Any suggestions?

 

[SPQQKY]

When using a 533 bus chip, you can only run sync or with a lower divider, you cannot run the RAM higher than the bus on those boards. You'll need a 800 bus chip to get your RAM to run its rated speed.

 

[kevotron]

Great Thank you so much!

 

[LTC8K6]

I believe it is running higher. I think it's running at a 4:5 ratio or 166(333DDR).