I built a new system with an ASRock X370 Taichi (3.20 BIOS, latest as of today) and a Ryzen 7 1700 this week. It overclocks decently, but as I can't get 3900 MHz to work together with OC:ed RAM (though it's stable with RAM at 2133), I went to 3800 and got it stable at a lower voltage.
It's stable in OCCT, both in "OCCT Small" and Linpack w/ AVX enabled, with the following settings:
CPU: 3800 MHz @ 1.250 V (LLC level 5), tested for many hours, plus gaming
CPU: 3800 MHz @ 1.225 V (LLC level 5), tested for 2h 15m
CPU: 3800 MHz @ 1.200 V (LLC level 5), tested for 1h, plus gaming 2 hours
RAM in all cases: 3200 MHz @ 16-15-15-32-1T, 1.35 V, CPU SoC @ 1.1 V
However, with each setting -- more often so with lower vcore -- I sometimes get a test failure at the very beginning of the OCCT test, when it ramps up the power usage (about 3-6 seconds in). If it passes the initial 20 seconds, it also passes an hour. Running for ~20 seconds, stopping for 5 and repeating seems to trigger the problem relatively quickly; 5-10 tries seems to do it most of the time.
I've read up on Vdroop and LLC and think I have a decent idea (I have a basic understanding of EE concepts) of how it works, and why LLC is considered bad.
However, since I use a low vcore and overshoot of even +0.2 V during load-to-idle transitions wouldn't really harm the CPU, I tested it anyway to see if it would help tackle this problem.
I tested levels 5 (most Vdroop), 3 and 1 (idle voltage = load voltage to within 0.001 V; it never changed a single millivolt during testing idle/load transitions), and managed to get a failure result out of all of them.
The LLC tests were at 1.2 V core voltage.
Any ideas on what I might do to take care of this?
Since it appears stable during load at 1.2 V, it doesn't feel right to go up to 1.275 V 24/7 (if even that is enough, I haven't tried it) just to take care of a problem that probably only lasts for milliseconds at a time!
It's stable in OCCT, both in "OCCT Small" and Linpack w/ AVX enabled, with the following settings:
CPU: 3800 MHz @ 1.250 V (LLC level 5), tested for many hours, plus gaming
CPU: 3800 MHz @ 1.225 V (LLC level 5), tested for 2h 15m
CPU: 3800 MHz @ 1.200 V (LLC level 5), tested for 1h, plus gaming 2 hours
RAM in all cases: 3200 MHz @ 16-15-15-32-1T, 1.35 V, CPU SoC @ 1.1 V
However, with each setting -- more often so with lower vcore -- I sometimes get a test failure at the very beginning of the OCCT test, when it ramps up the power usage (about 3-6 seconds in). If it passes the initial 20 seconds, it also passes an hour. Running for ~20 seconds, stopping for 5 and repeating seems to trigger the problem relatively quickly; 5-10 tries seems to do it most of the time.
I've read up on Vdroop and LLC and think I have a decent idea (I have a basic understanding of EE concepts) of how it works, and why LLC is considered bad.
However, since I use a low vcore and overshoot of even +0.2 V during load-to-idle transitions wouldn't really harm the CPU, I tested it anyway to see if it would help tackle this problem.
I tested levels 5 (most Vdroop), 3 and 1 (idle voltage = load voltage to within 0.001 V; it never changed a single millivolt during testing idle/load transitions), and managed to get a failure result out of all of them.
The LLC tests were at 1.2 V core voltage.
Any ideas on what I might do to take care of this?
Since it appears stable during load at 1.2 V, it doesn't feel right to go up to 1.275 V 24/7 (if even that is enough, I haven't tried it) just to take care of a problem that probably only lasts for milliseconds at a time!