Hi guys. Recently built a system with 14900K, ASRock Z790 Nova motherboard and [*THIS*](https://www.corsair.com/us/en/p/memory/cmt64gx5m4b6600c32/dominator-platinum-rgb-64gb-4x16gb-ddr5-dram-6600mhz-c32-memory-kit-black-cmt64gx5m4b6600c32) 4 DIMM 6600 MT/s RAM which has 32-39-39-76 timings.
Initially when I got the RAM, I plugged it in, turned on XMP, and the RAM passed several multi-day stability tests in TM5, Karhu, etc. Then I momentarily took the RAM sticks out and since plugging them back in, XMP no longer works. I can’t even POST successfully.
Weird thing though is that if I set the same 6600 MT/s speed and 32-39-39-76 timings manually, I can boot into Windows and the RAM appears to be stable. But then if I switch to XMP, the system barfs again.
[Here’s a screenshot comparison](https://imgur.com/nA6HG7y)
Left: Manually set speed and timings on all 4 DIMMs
Right: XMP enabled on just 1 DIMM in slot #4
**Can someone suggest why manual settings work but not XMP (even though it worked earlier) ?**
1 Comment
Did you manually change any of the secondaries or tertiaries?