can different cards work in a PC for mining?

[Supercrit]

New to here, currently using a 5770(935/300) doing 200mh/s, getting a 6950 soon(is that a good card for mining?) and will try to unlock it.
So, If i put these 2 cards together under windows 7 will they both work at the same time?
Also, is 200mh/s worth the time doing so? what's the speed that makes mining worth it?
Thanks all.

[1713918446]

1713918446

[lolcat]

Hello, I'm Lolcat and I'll be assisting you today.

When you're second GPU arrives you are going to want to take a look at this guide: http://bitclockers.com/forums/index.php?topic=7.0
By default, Windows will not engage you're second GPU unless there is draw from a monitor. You can trick Windows and devise dummy plugs (as mentioned in the guide)

For your second question, here is a simple easy-to-use 'Profitability Calculator' you can use to determine "if it's worth it"
http://bitcoinx.com/profit/

-Lolcat

EDIT: Yes, 6950's are great
EDIT2: I'm not a mod I just like to talk like a sales representative.

[Supercrit]

Hmm so I need a dummy plug? does regular DVI->VGA adapter work?
Thanks for the fast reply

[1984]

An active DVI->VGA would but the standard ones that often come with cards are straight pass through, the post above is an excellent example of how one of these adapters can easily be turned into a dummy plug. Be careful about your choice of 6950, some aren't unlockable and in some cases won't accept rom flashes at all even though they appear to, your best bet is a proven 2GB reference design.

[Supercrit]

so I need to get some resistors at radio shack...
About the 6950, I purposely bought a reference sapphire 2GB on ebay, for 255$ CAD ship included, hope it unlocks =P, and reference cards just look better, fancy flashy cooler is not my thing, simple elegant design is better.

[lolcat]

That card should work excellent.
As for the dummy plug, you should be able to construct one for under $10

-Future customer support specialist, Lolcat

[ssateneth]

Dummy plugs didnt even cost me that much. Maybe $0.60 USD each (the dvi -> vga is "free" with all retail boxed video cards these days, the the resistors were about $1 for a pack of 5, needed 3 for each plug).

Why would they cost $10 each O_o

on topic: yes different cards will work just fine, even ati and nvidia mixed. just make sure you have dummy plugs or monitors to hook up to each card.

[Supercrit]

Another thing to add, does MSI afterburner work for 2 cards? Can I OC 2 different cards at once? Or I need another program?

[nafai]

Yeah you can use MSI afterburner to handle the OC for all your cards.

[lolcat]

Here a pack of 100 ohm resistors is like 5 dollars and this is assuming he would need to buy the adapter.

[DrHaribo]

I don't know why, but I never needed a dummy plug. Running on 64-bit Windows 7. Maybe needed only on older Windows?

Earlier the machine had a Radeon 6990 and GeForce GTX 580. Now it has a Radeon 6990 and Radeon 5970.

I've always been able to mine on all GPUs without any dummy plugs.