AMD Compatibility

Testing on AMD proved quite interesting. First, I tried the default JEDEC profile on the HyperX Predator RGB sticks, and what I found was exactly as expected.



Next, I tried the 2933 MHz profile, and I got a surprise when I booted into the OS. Instead of CAS 15, the sticks were running CAS 16! I went back into the BIOS to check things out.


I made sure to manually input several timings and then rebooted back into the BIOS. What I found is pictured above. I simply could not get C15 to work at all! I tried C17, and that didn't work either... but it did with the JEDEC profile? Weird.



As you might expect (or not), C15 and C17 did not work with 2666 MHz either. Seems to be a platform limitation. This might also explain why we had some serious memory problems with Ryzen when that platform launched, and this is how they were addressed? Seems to be, but I could be wrong about that, of course. Either way though, C15 on AMD just seems impossible, and it does not seem to have anything to do with the HyperX Predator RGB DDR4 sticks.