Topic: Get The Most MHash Out Of Your 6970! (Read 5087 times)

Why don't you try new phatk 2.1 kernel https://bitcointalksearch.org/topic/modified-kernel-for-phoenix-15-7964 it's faster than modified 1.0

Use the optimized phatk kernel I listed you'll get +25 mhash without any overclocking at all...

Have you tried 340 MHz speed for memory? This seems to be optimal for my vanilla 6970. 407 MH/s at 920 core/340 mem with latest poclbm.

It actually only uses 50 watts more hehe

Hey never let physics get in the way of a good idea...

buy a kill-a-watt and figure it out =P

See if its worth it to do the extra voltage for the little more mh/s

Sorry to be off-topic a bit, but does the power draw of a 5830 matter? I have it maxed out at 1195 using Trixx with clocks at 1000, memory at 300 and fans at 100. I'm getting 315 mhash/sec but am wondering if I'm overdrawing power? I've got 3 5830s in my rig. Thanks for any input.

When calculating the optimal overclock, it makes a huge difference if you have a multi-gpu rig or not. If you just have a single GPU, the proportion of power draw from the card will be relatively lower than in a multi-gpu setup. In this case, it might make sense to overvolt and overclock.

In a multi-gpu setup, minimizing power usage is the priority.

This is a bad idea. You're better off running it at 900mhz, no overvolt and 400 mhash. Those extra 40 mhash are costing you a ton in power usage, you're losing money on the deal. The chip/vram are hotter, the fan has to be higher, it's great for showing off but once you're done clock it back down.

power = volts squared  divided by resistance.


lets say 1 volt and 2 ohm== 1^2/2ohm = 1/2 watts

now lets see 2 votes   2^2/2=2 watts

we doubled the volts but quadrupled the watts.


now I know people almost never double the volts.. but the point stands, you often lose more in watts per hash, than you gain in total hashes.

people seem to be solely concerned with hash rates, when you really should look at the total picture. I know people who actually under volt their cards and underclock them, to get the best hash rate per watt.

I wouldn't clock your cards that high. The power draw increase severely cancels out the bitcoin earnings.

http://forum.bitcoin.org/index.php?topic=30582.0

Everything has been stable for 2 days hope this works out for everyone

So I have been getting 447 mhash/s on my 6970 using Phoenix with an optimized kernel. First you want to get the phoenix miner use the normal phoenix miner or the one that comes with the updated gui miner both work great. Here is a link for the normal phoenix miner! http://forum.bitcoin.org/index.php?topic=6458.0 Here is the link to the GUI Miner! http://forum.bitcoin.org/?topic=3878.0. Once you have it downloaded install the custom kernel, but I assume you already have it... But anyways here is the amazing kernel that gives me +25 mhash if you guys are not using it you should use this optimized phatk Kernel works great. Here is the link for the optimized phatk kernel https://forum.bitcoin.org/index.php?topic=25135.0 replace the files in the gui miner with the new files in the rar from the optimized phatk kernel then you should be set. The next step is to overclock your 6970 as much as possible but make SURE you do +20% in the power options in the CCC in AMD overdrive to fix the really low mhash issues. Also try and get 1000 mhz if you can;t go that high try 950 or 970 980 990 whichever you can get stable you don't need to go above 1250 mV to get the 1000 mhz oc but if you can do it you should be fine I also find leaving the memory alone gives you the best results fi you go down to 600 or 300 or 188 you will see a loss in mhash for some reason I think it's not worth it. ENJOY!

Here is the screenshot of my mhash :



AMD Overdrive +20% Power Tweak to avoid really low mhash.