Originally Posted By: hybrid8
If I set the mobo with Memory Frequency to AUTO, it will run 399MHz even though it's also set to use SPD. So I turned off SPD to set the latencies manually, set the clock manually and even set the voltage manually.

Is this the same EPP RAM from before? If so then unless your board specifically supports the EPP extensions, it will run it at conservative settings. Blame the tweakers for EPP. It is mainly for overclocking RAM.

What board and RAM do you have?

Originally Posted By: hybrid8
clock of 399MHz (DDR800) instead of 533 (DDR1600)

533MHz is DDR2-1066.