Bitcoin Forum

Hi,

Recently I just bought a new pair of 7850. They are crossfired. I noticed, that the activity will never reach 100%. It always hovers around 80%~95% for both card. Is this normal because of the crossfire?

I am using GUIMiner (OpenCL) with extra flags "-v -w128 -f60".

My previous card can mine at 100%. But this is a single card setup.

Thanks

Yes you need to disable Crossfire in order to get ~99% usage.

That's it.

Can also try a significantly lower f number. A higher f number means more responsiveness of the desktop at the cost of less GPU time dedicated to actual mining. A lower f number will enforce "bigger" nonce ranges per kernel run, causing more desktop lag but more dedicated gpu time to mining. You can think of f as the framerate, but a lower framerate means better mhash.

Got a CF Setup with 5850, if i disable Crossfire, the second card will be disabled for mining.
So i thing it's recommendet to enable CF.

I have 2 multi GPU PC's mining, none of them use crossfire and they all mine fine.

No. CF is not needed for mining. I use a dummy plug for my second 5850. This way I can set the speed for each card as I want.

Hey ok, now without CF the second card gets 99% work, before it depends on 96%.
I got a small issue with CF off, the clocks/profile still dont work. But it's very simple, shut down Afterburner and restart, vóila.  ;D

I actually use 2 5850's with cf disabled mining with guiminer. I am unable to use any f value with both cards running at the same time. Nonetheless with -v -w 128 they both mine at 99%. Just for info purposes I was wondering what kind of hashrates your dual 7850 setup puts out. Also specific cards and clocks info would be nice to know as well. Thanks

On my @home PC I have a 5850 and 5770 mining 24/7 the 5770 is my desktop card and has the "-f 60" flag. The 5850 has the "-f 1" flag.. There is no reason that you cant add the flags to guiminer.

@Andrew
Sorry, I should have given more details about not being able to add f flags on my setup. It is possible for me to give each miner an f value, but for some reason the miners will not respond correctly...at least for a long period of time. For example if I give both cards -f 0, one card will go full blast and the other will only mine at about 70%. So I figured I just can't use the same value for each card and tried -f 0 for one card and -f 1 for the other and it still does weird stuff and doesn't just keep a constant 99% on each card. If I use no f value on either, they both at least stay at 98%. I will do a little experimenting tonight to see if I can get it to work. I hope I explained my situation in enough detail and if you could help me get both the cards full throttle that would be awesome. Thanx for listening at least