Just thought I would share how I got my XFX HD 7950 optimized.
When I bought these cards they where a nightmare. Voltage locked, thread concurrency stuck at 8192 max, boost function causing them to throttle and running very hot. Initillay I could not get these to run with any intensity higher then 13 on CGMINER
This is my setup:
- 2 x XFX HD7950 Double Dissipation (FX-795A-TDFC)
- MSI Z87-G45 Gaming,s1150
- Intel Core i3-4130,s1150
- 1 x TNAV6R00 Corsair RM1000 (Gold standard)
- ICIDU Value DDR3 1333-2GB (2x4GB)
- Windows 7 Home Premium 64Bit
And this is what I did:
Step 1: use setx commands always!- setx GPU_MAX_ALLOC_PERCENT 100
- setx GPU_USE_SYNC_OBJECTS 1
Step 2: Bios flash to change voltage and remove Boost - extracted my bios using GPU-Z, three times just to be save.
- modded using VBE7
- under 'powerplay' -> 'Performance state': be sure to set state 0 and 6 to the same values, as this removes boost.
- under 'overdrive & powertune' -> 'powerlimit': added 10% to the watts (be sure to stay below 300 though). This also depends on your ASIC value.
- loaded the mod. bios using ATIwinFlash
- i run a crossifre setup and I flashed one card at a time, just to be save (these cards don't have a Bios switch). Tested before flashing the second card.
Good read:
http://www.techpowerup.com/forums/threads/vbe7-vbios-editor-for-radeon-hd-7000-series-cards.189089/End result was a temp drop of about 10c. I can now run these cards stable at V1.091 with GPU/MEM 1120/1500
Flash the BIOS at your own risk, If you are not sure what you are doing, or how to undo it, then don't do it!Step 3: Reinstal Windows and Radeon drivers, full install with format and use latest Radeon drivers.This solved my max thread concurrency issue (massive headache that was). I can now set thread concurrency above 40000! (which is pointless btw). This also allowed me to reach Intensity 20
Step 4: fine tune GPU/MEM settingsI used the tool found here:
http://www.holynerdvana.com/2013/12/finding-optimal-clock-speed-for-cgminer.htmlAllows you to find the sweetspots regarding mem and gpu, in a automated way. Takes some time to run, but it pays of! I would advice running the mem test first, with GPU at 1050 or so. Here are some of the things I found using this tool:
- increasing GPU above 1068 with mem at 1250 was pointless
- increasing GPU above 1080 with mem at 1380 was pointless
- setting mem between 1250 and 1380 was pointless
- setting mem between 1385 and 1455 was pointless
- Increasing mem above 1500, with GPU at 1120, was pointless
I guess results will be different for each setup though.
Step 5: fine tune thread concurrencyI used the tool found here:
http://www.holynerdvana.com/2013/12/cgminer-optimal-thread-concurrency-for.htmlThis test can take a long time. It also has the tendency to crash in between, meaning you need to keep an eye out. No worry if it crashes though, just reboot and continue.
In my case, TC 22712 got me the best results so far: a stable 660. Again, results can be different depending on the setup. Keep in mind also that the highest thread concurrency is not always the best.
My final CGMINER bat file now looks like this:
cgminer --scrypt --gpu-engine 1120,1120 --gpu-memclock 1500,1500 -o x -u x -p x -I 20 --lookup-gap 2 --thread-concurrency 22712 -w256 -v 1 -g 1 --gpu-powertune +20,+20 --auto-fan --temp-target 70,70
I am still playing around a bit with finding the optimal airflow. These cards can still run hot at these settings. Some of the things I did to cool them to 70c where:
- moved my rig into my garage (non heated).
- placed extra fans around the GPUs (blow in from front and side, blow out from back and top). Computer fans don't really use much watts, so no need to cut down here.
Perhaps i'll upgrade the GPU cooling system at some point, but only after winter has passed.
Good luck tuning!