Help with clocks and timings with Ryzen 9 5950X and 4000 MT/s RAM
I'm looking to overclock my infinity fabric / memory speed to as high as I can and then adjust the timings and CPU afterward, but I'm not sure if I'm approaching this correctly. The purpose is mostly for learning and lulz.
I have a set of 4 x 32GB Trident Z Royal memory and a Gigabyte X570S motherboard. The XMP profile for the RAM is DDR4-4000 CL18-22-22-42 1.40V.
RAM: https://www.gskill.com/product/165/299/1601284845/F4-4000C18Q-128GTRS
Motherboard: https://www.gigabyte.com/Motherboard/X570S-AORUS-MASTER-rev-10#kf
However, I cannot boot with 4000 MT/s with a 2000 MHz FCLK. I also cannot boot at 3800 MT/s and 1900 MHz FCLK, so I'm at 3733 MT/s and 1867 MHz FCLK. It seems 1900 MHz is a strange issue for Ryzen processors, with 1933 or 1967 sometimes working while 1900 does not, but I haven't tried them.
I scaled the main timings down based on the RAM downclock: 3733 = 93.35% of 4000, so I have set:
tCL: 18 -> 17 (16.803)
tRCDWR: 22 -> 21 (20.537)
tRCDRD: 22 -> 21 (20.537)
tRP: 22 -> 21 (20.537)
tRAS: 42 -> 40 (39.207)
Voltage: 1.2V -> 1.4V
Are these timing adjustments scaling down to the downclocking reasonable? I have done multiple 2h OCCT RAM tests with both AVX2 and SSE without any errors, so this seems 'stable'. Is it worth trying anything lower than these conservative timings scaled down from the XMP profile? I ran one OCCT RAM test with 16/20/20/20/39 and it passed with no errors as well.
The issue is now when I try to do anything with the CPU, it seems very unstable. I'm currently at -29 for all cores in the curve optimizer, with the four best cores at -14, -21 (CCX0) and -16, -23 (CCX1), 300W PPT, 170A TDC, 190A EDC, -200 MHz Boost Override, 'Auto' VCORE (1.2V), 'High' Load Line Correction.
Am I going about any of this the wrong way?
Is it expected that I should be able to drop RAM timings relative to the underclock of MT/s or should I just leave them at the XMP timings at 3733 MT/S?
Do I need to Boost Override even lower because of the Infinity Fabric being at 1867 MHz?
Is it worth trying 1933 or 1967 FCLKs? Or drop even further to 1800 or 1833?
Are there any services specific to Ryzen overclocking that are worth paying for? I wouldn't mind paying for an hour of someone to video chat with that could give me some guidance on how to go about this and where I should approach this differently, but they don't seem to be worth the $.
For what it's worth, ZenTimings reports 18/21/21/21/40 even though it's set at 17/21/21/21/40 in the BIOS.
Posted May 15, 2024, 3:48 AM UTC · edited