Quote from: forgotmypants on December 22, 2013, 06:05:18 PM

Hi Guys,

I have recently bought a sapphire radeon r9 280x for litecoin mining.
I have tried several different cgminer settings and so far this is giving me the best results so far ( 700 kh/s )

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer --scrypt --intensity 13 -g 2 -w 256 --lookup-gap 2 --temp-target 70 --auto-fan --temp-cutoff 90 --thread-concurrency 8192 --gpu-engine 1000 --gpu-memclock 1500 -o stratum+tcp://world.wemineltc.com:3333 -u workername -p password

Ive read people get 750 kh/s with this card, so if anyone can help me out with that?
I tried playing with thread concurrency and set it to 11200, also set memclock lower but none of those help.

Also i heard about undervolting the card, but i am not really confident doing that.

At first check your BIOS version via GPU-Z if it contains string similar to 15.41.XXXXXXXXXXV42, you're not the lucky one and bought one of the "throttling" series. On this card the VRM temperature is to high and you need to lower the voltage. Try voltage change to 1,089V (use Sapphire Trixx software not cgminer argument) and provide good cooling (temps 73'C or less). With this card you're able to do approx 740kH/s.

If you have other BIOS version, you can do up to 780kH/s with increasing GPU engine to 1130MHz (1150mV / 63'C in my case).

The best params I've found are generally based on 8193 thread concurrency.

CGMiner settings:

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
del *.bin
cgminer --scrypt --intensity 13 -g 2 -w 256 --lookup-gap 2 --temp-target 68 --auto-fan --temp-cutoff 90 --thread-concurrency 8193 --gpu-engine 1050 --gpu-memclock 1500 -o stratum+tcp://middlecoin.com:3333 -u 1ETYyETSWhkVxyj7HrBVEr5iAxAx2uSfTe -p x

Wink

If you're desperate, try PM me and I can try to solve it for you via remote desktop or similar SW.