Bitcoin Forum

Hey guys!

I have a simple question, i know this thread isn't where it belongs but considering my newbie status i have no other choice but to post here.

I got a midtower with a GTX560ti (384cores) clocked at 1GHz (105MHps), a Phenom II X4 for about 14MHps
and an extra GTX 260 (estimated for around 46-47MHps)
I run Guiminer to get everything running

now my problem is the following:  I can't run both GPUs at the same time :/

either one or the other will start mining while the other stays idle.
furthermore, my OpenCL miner is blocked (gos knows why, I have the latest drivers, the CUDA toolit, drivers,  the works..)
I've heard of Dummy-plugging a GPU to fool it to be plugged into a screen to be active?

Any ideas to help me out?

thanks so much in advance!

Keep calm and mine on!

I've never tried to mine on Nvidia cards or a CPU since neither are recommended.
At the very least only try mining with the Two GPU's, not the CPU.
Yes I have heard dummy plugging does or did work.

Keep in mind, that mining with your current setup will not produce that many bitcoins and electricity wise will probably cost you more than it produces. If you okay with that, good luck.

don't worry, electricity is dirt cheap where i'm from ;)
and as for hardware,  i'm in the process of getting new stuff,  this is just my gaming rig and a friend's old gpu so i can get a (small) head's start

and that's the thing,  i CAN'T run both at once,  OpenCL is disabled for some obscure reason and with the CUDA miner i can only run one at a time. Is there some specific flag I have to append?

You sure you have enough power in the box to run both cards? Maybe the secondary card isn't getting enough juice....

...I have a 1kW PSU,  i think it would be the least of my worries ;)

True dat. Just askin :D

Hmm. your OS sees/recognizes both cards? try running the a separate instance of the mining software in a "sandbox" OS shell and point it to the second card?

I've done this. You can actually get the parts for this:
http://www.geeks3d.com/20091230/vga-hack-how-to-make-a-vga-dummy-plug/
at Radio Shack of all places. Remember the line "Any resistor between 50 and 150 ohms is okay." I think the ones I got were 65 ohms. The VGA plug itself probably came with the card as an adapter to VGA that you plug into the new style video port.

sweet, a DVI hack! I wasn't sure which leads were which! :D

Also,   sandbox?  are you talking about an isolated VM?

I recommend switching to pooler's cpuminer for the cpu and using either reaper or cgminer for your gpu's.

pooler's cpuminer won't require more than the username and password to get the best hashrates out of your cpu.

Using reaper with the right settings will most likely give you the best speeds but it can take some time and serious effort to dial in your settings. If you're not too technically inclined, go with cgminer for gpu's as it gives the best hashrate aside from reaper and is much simpler to use and will give you great hashrates with very little configuration.

If you go with any of these programs and need help getting setup, shoot me a message and I will be more than happy to help out!