Post
Topic
Board Mining (Altcoins)
Re: XMR RandomX mining with Ryzen 3900x
by
Walrusbonzo
on 29/03/2021, 19:21:46 UTC
I've found noticeable uplifts in performance from tuning RAM timings on my 9900K, 3950X and 5950X systems.

I'll fish out some exact numbers later from the 5950X system. I'm not sure it's 25%, but it's quite a hefty bump, I'm sure it's over 10%.

A breakdown would be interesting to measure the effects of enabling huge pages, disabling next line prefetch,
and adjusting DRAM timing.

For 24/7 running of XMRig I set a fixed CPU Vcore of 0.975v. This allows fixed clocks of 4.2GHz on the first 8 cores and 3.85GHz on the last 8 cores and a relatively low CPU package power reading of 133w in HWINFO64. RAM frequency is 1866MHz(3733mt/s) and IF is set to 1:1 with RAM frequency. There shouldn't be any random core boost behaviour affecting these results.

I'm using XMRig 6.10.0 with all 32 threads activated as this provides the best performance.

My 24/7 settings, tuned RAM timings + huge pages ON - 19,830 h/s

Tuned RAM Timings + Huge Pages OFF - 18,350 h/s.

Stock RAM timings + Huge Pages On - 17,480 h/s.

Stock RAM timings + Huge Pages OFF -  14,275 h/s.

Ordering the performance uplift from each change combination
Huge pages off to on for Tuned RAM timings gives a 1480h/s uplift, 8%
Stock RAM timings to Tuned RAM timings with Huge Pages on gives a 2350h/s uplift, 13.4%
Huge pages off to on for Stock RAM timings gives a 3205h/s uplift, 22.5%
Stock RAM timings to Tuned RAM timings with Huge Pages off gives a 4075h/s uplift, 28.5%

It seems for me, tuned RAM timings provide a bigger performance uplift than using huge pages. Turning huge pages on gives a bigger benefit where stock/poor RAM timings are used.

You're probably wondering what RAM timings I've tuned. I change nearly all primaries and secondaries, some tertiaries too. Command Rate is 1t and GDM is on in both cases.

Stock primaries are 18,20,20,44,92(RC). Tuned I'm running 14,14,14,30,44.

I can't remember stock for the following, but I tune tRRDS 4, tRRDL 6, tWTRS 4, tWTRL 12, tWR 12, tCWL 14, tFAW 16, tRTP 8

You've probably guessed I'm running RAM sticks with Samsung B-die Wink I'm running 4 sticks as well so Rank interleaving is enabled also. Not sure how much that is helping me.