Hi Claymore,
i get with R9 280x 15.5Mh only not 20Mh
How can i improve it ?
Its normal for 280x.
DEPENDING HOW HOT YOUR ROOM IS--
280X cards run hot and eat power. If your cards are overheating, you may need to downclock, and earn 15-16MH/s per card. If you set "-dcri 15" in your config, you will reduce the intensty of your secondary coin by 1/2 and give your 280X cards more room to breathe; they will run faster and at lower temperature. If you set "-cclock 1100", you will overclock your card, increase the hash rate, and increase the temperature of the card. A core clock of 1100 may not be stable for your card/rig, you have to check postings by other miners regarding overclocking. If you set "-tt 87", your card will self regulate, attempting to keep the temperature at or below 87 deg F. If you are in a hot room, your hash may be 15-16MH/s because of temperature throttling. My 280X cards made 22MH/s last winter, when the room was cooler, and the difficulty lower, and the DAG smaller.
All of this and more is in the README!!!.txt file, you should study it. --scryptr
scryptr - will the Stilt BIOS help maximize 280/280x for ETH mining? Thanks
THE LEGENDARY STILT BIOS MODS--
Stilt BIOS mods are from the days of LiteCoin (LTC) and its meteoric rise prior to the Mt. Gox hack There is a thread for those still interested.:
https://forum.ethereum.org/discussion/5937/gpu-optimized-stilt-bios-anyone-have-them] . Some users of the modded BIOS are able to point to the location of these legendary files, other users are downloading the entire archive to preserve the treasured data.
I have never flashed my recently ROI'd 280X cards. It can affect the resale value of your cards if detected. From what I read in the above Stilt BIOS thread, there is no guaranteed hashrate improvement, even if you flash your card. The thread is still short, and a good read. It points to the old, archived, 100+ page Stilt BIOS thread where I may find myself reading about the Black VooDoo of BIOS modding.
Bottom line, a BIOS mod is not a sure thing, and you need to save a copy of your original manufacturer's BIOS in order to set things back to default. --scryptr
Most cards have a dual bios switch. If you screw up one, just flip the switch to the other. You can fix the bad one (if you have dual bios). People flash vbios all the time, even card manufacturers provide updated vbios so it shouldn't affect your resale value (just make sure you have a switch). In my experience with stilt and eth mining, I didn't see a significant hashrate improvement but I did see lower temperatures, not dramatic but still there, especially with Hynix memory.