Topic: Guide: How I got my XFX hd 7950 from 380khz to 660khz (Read 4289 times)

Not sure. Anywhere between 200 and 300 watts I guess...?

I've just ordered one of these cards, so hoping this will prove useful in a few days. What BIOS did you change to? And do you know how many watts the GPU is using?

glad to see this thread is helping  

I have actually been running my cards at 1080/1455 now for a while, giving me a stable 640khz per card. I can still run 1120/1500 stable, but I personally think it is not worth the 20khz increase per card. The cards run hotter and consume relatively more watts per hz at this level

I have now also added a HD5850 to my rig. Was initially looking for a HD 5870, but am happy with my 5850 also. I personally really like these cards. You can find them for a bargain second hand, they run cool (about 58 celsius in my rig), are actually rather energy efficient (unlike the HD 6xxxx series) and easily reach 350khs per card for the 5850 and up to 400 for the 5870, with plenty of tunning room to spare.

Only problem is now the heat in my rig. From top to bottom I now have installed

- HD7950 -> runs at about 70c
- HD5850 -> runs at about 58c
- HD7950 -> initially ran at about 80+c. Now I got it down to around 74c

I had to adjust the airflow in my case from a underpressure setup to a overpressure setup, applying a massive disruptive airflow from the side using multiple fans, while protecting the airflow intake near the GPU fans. As always, still fidling on how I can get it better. I have my eyes on some USB cable based powered risers. I am rather sure that using these risers I can create a setup with a further drop in temps; it's all in the spacing and the airflow.

Will post the results on this thread. Could take a while though before I get around to it.

Cool, thanks for going through the benchmarking. Tried it too a while back, but gave up after a bunch of crashes. Using your TC now for 2 XFX HD7950 and that nets me and additional 20 to 30 Khs per card!

Ok so something odd.

It has run through but reported the same hashrates for every setting. Even settings that I KNOW provide good and/or poor hashrates.

Anyone know what's up with that?

Ah. Seems like the powertune being set to 50 was making the clocks wig out.

So far 1200-1510 memory speed makes almost no difference. 1370 was higher than the rest by like 2kh but had a noticeably better WU, so I picked that one.

Running the GPU clocks now. 775-1300

Not sure why no one else picked this up. But I'm trying this out now.

Finding the right clock/mem is very tedious. Something to automate it would be excellent. So far running the memory file now. And will follow up with the GPU speed file, then TC. So far unlocking the voltage via re flash worked well. I also decided to set it to 1.09v.

I had my XFX 7950 DD up to about 630KH, but if this gets me some more, then I'm all for it. I'll probably re flash the card to the stable settings when done.

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 settings
I used the tool found here: http://www.holynerdvana.com/2013/12/finding-optimal-clock-speed-for-cgminer.html
Allows 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 concurrency
I used the tool found here: http://www.holynerdvana.com/2013/12/cgminer-optimal-thread-concurrency-for.html
This 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!