Post
Topic
Board Mining (Altcoins)
Re: AMD Mem Tweak - Read/modify mem timings on the fly - [Vega Friendly] [Win/Linux]
by
kamisama233
on 29/05/2019, 11:43:56 UTC
For anyone else using the old PBE one-click samsung straps (aka generaleramon's ubermix 3.2) on RX 4/5XX 8gb GPUs, and seeing subpar ETH h/rs due to the tight timings limiting mem clock frequencies... I've been able to get my samsung 580-8s more in-line w/ the microns (~32.5 MH/s) by loosening a couple settings which then allow raising the mem clock (combined w/ a REF increase i use on all my 580s):

--REF 10 --RC 70 --RFC 157 (from REF 5, RC 65, RFC 136)
mclock 2145-2185 (from 2085-2145)

other relevant bits:

cclock 1175, 806mv, phoenixminer, and ubuntu 18.04 + amdgpu-pro 18.50 (though windows should behave similarly)

You could prob get to ~33+ w/ a 1200-1250+ cclock, while I may have slightly overshot on the loosened timings.  But as usual, I'm more interested in efficiency than max h/rs.
Also, mclock is still a bit limited, as i believe CL (currently 21) would need to be relaxed to get to 2200+ MHz -- which as i understand, can't be done w/ the tool atm.

excellent, how can you lower your 580's voltage to such a low level with a 1175 frequency, core and memory voltage all at 806mv, that's impressive, how to lower, thanks

No tricks - i just set them that way (I use ppts, but that's prob not necessary.)  Not all cards can do the same - my range on 580s for ethash is 800-837mv, though I haven't been super-detailed on tuning all of them, so the range could be lower/tighter.

Also, proper cooling can help a lot... More heat = more power use, and not just because of higher fan speed.  I have mostly sapphire nitros, w/ a fair amount of spacing between GPUs (enough for ~120mm fan between each) and some decent airflow which keeps my temps in the low-mid 40s mostly.
580 with ppt?, isn't that only vega support ppt? how to set 580's ppt?