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Old 2020-05-31, 19:18   #278
ewmayer's Avatar
Sep 2002
Rep├║blica de California

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Originally Posted by Uncwilly View Post
That is one ugly beast.
That depends on what one finds beautiful in such a thing. :) The typical setup inside an ATX tower case system with multi-GPUs ain't any prettier.

Update on the power usage - I had been running both cards 1 and 3 (the 2 rightmost in the pic, my numbering is based on the order they appear in the ROCm listing) at sclk = 3, but card 1 was able to handle mclk = 1200 whereas card 3 was not, had to dial the latter down to 1150. I noticed, though, that the timings differed by maybe at most 1%. Dialed card 1 down to 1150 as well, that cut 20W off the usage, with the stated 1%-ish timing hit. So did same to card 2 (which had been running at sclk = 4, mclk = 1200), another 20W cut, and that card - which was marginal @mclk=1200, at that point it was ~20% through a PRP run @5.5M FFT, with 18 G-check errors for job1 and 19 for job2 - also runs much more stably at the lower mem-clocking ... over 12 hours after the mclk fiddle, no addition errors for the 2 runs, both now ~60% done.

TDP now ~750W, still a bit on the high side for my PSU, but better.

So the general idea is: Use the sclk setting as a coarse dial on performance and wattage, and mclk as a fine control.

Last fiddled with by ewmayer on 2020-05-31 at 19:19
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