Ram issue or compatibility issue?

[Ryann]

So my computer won't boot up if my ram frequency is over 1600mhz. My Sabertooth z77 supports up to 1866, but my ram is 2133... Specs in sig.

[chaud]

Have you increased the voltage / tried with a stock CPU speed?

[lloose]

Is your bios up to date?

[vesseblah]

Your CPU-Z sig shows the RAM running at 1066MHz which is correct.

It's always half of the advertised speed because DDR = double data rate, therefore 1066MHz actual speed is 2133MHz effective data speed doubled.

[Ryann]

Yea I'm aware that 1066 is 2133. I actually had that running in XMP and I believe PLL overvoltage was enabled so it was able to boot and pass a stress test. But I kept getting IRQL not less or more BSOD's, and I read that could be a memory problem. Memtest shows no problems with my ram, but the BSOD's persisted when I'd get into any game for longer than like 1 minute. I dropped XMP and the ram frequency to 1600 and ran my OC to 4.5ghz@1.25v and I haven't had problems since, but I got the itch to try to get my ram running like it should and I just can't... It's very frustrating.

I haven't tried booting 2133Mhz at stock CPU speed.

I haven't updated bios but I didn't think I had to since the Z77 Sabertooth is a brand new board.

And my ram voltage is at 1.65 already, which is stock. I read that upping voltage past that is dangerous.

[vesseblah]

And my ram voltage is at 1.65 already, which is stock. I read that upping voltage past that is dangerous.

Most Z77 boards downclock RAM if it runs at higher voltage than 1.5V, I bet that is your problem. 1.65v was accepted although not recommended with Sandy Bridge, but it's no longer officially accepted with Ivy Bridge although most boards handle those with variable success.

[chaud]

Yeah, don't increase the voltage anymore. Running at 1600 is a net loss of maybe 1% of performance or less in almost everything that isn't a memory intensive benchmark.