Post
Topic
Board Computer hardware
Re: [WTS] First Batch of Gigabyte 280x NIB + USB risers
by
crazyates
on 15/02/2014, 00:44:00 UTC
First round of cards should be in the office by this evening. Second round should be soon. Still have some for sale!
Any chance you can share your config for getting 740khs?  I can only swing about 725
Sure. If you've got the F60 BIOS, flash it with The Stilts's modified F60 from the Litecoin forums. He tweaks the RAM timings, and allows you to OC your core farther before your hashrate drops off. If you've got the the F70 BIOS, you're all set. Those F70s hash like a mofo beast.

(F60 designates that is uses Elpida RAM, while F70 designates that is uses Hynix RAM. If you've followed scrypt for any time, you'll know the difference and know it is not insignificant).

For both versions, use the same settings: 13.12 drivers, sgminer 4.1.0, tc 8193, g 2, w 256, I 13, and fan 80%. Don't use auto-fan or temp-target or anything else.

If your mem can OC far enough (>1800), then set your mem to that. I use 1810 on the cards that can. If you can't hit 1800, stick with 1500. Between 1500-1800 is crap, but once you get over that 1800 hump, you can rock some good settings. I have yet to get a F60 card over 1800, but some of the F70s can. Most of our cards run at 1500.

Then, start your core at 1025 and work up in 5mhz increments until your hashrate drops off. On an unmodified F60, this will happen somewhere around 1020-1050 for ~710-725kh/s. On a modified F60, this allows that same card to go up to  1065-1085 for ~740-755kh/s. On a F70, this happens somewhere around 1100-1125 for ~775-785kh/s. On the F70s that can OC the RAM to >1800, this drop off will happen closer to 1130-1150 for ~795-810kh/s.