Best bang for the buck today?
Looking to build my first GPU setup for hashcat. I have an Asus P7P55D Evo motherboard with an i5 and 8GB of RAM. Nothing in either of the PCIe16 or 1x slots. Main focus will be on WPA2 and is what I am basing my calculations and expectations on. Power consumption is not so much a concern as it will not get a ton of use and it wont be mining bit coins.

I am getting my numbers from this site and have my eye on 2 6970's as I can get them for about $100 a piece. From what I gather two of these would crack WPA2 slightly faster than an R9 290 but a bit slower than a 290x, around 160k h/s.

Running the math it seems 2 6970's could run through a 10 digit all numbers WPA2 key in less than two hours where my i5 would take nearly 45 days.

From what I have read it sounds like I can use the 2 1x slots as well with the proper adapter if I would like to expand later. Any other options or insight would be appreciated. I could have this all wrong as I am only going off price and the estimations from the above site. If I am missing anything or there are better options please let me know.

Thanks for doing your homework before posting! You have a bright future here.

You're on the right track and you definitely have the right idea buying used. However, 'best bang for the buck' really depends on how much you can snag each card for.

6970 is a good card, but it is VLIW4. If you can, try to pick up a GCN card instead. 7950 is faster than a 6970 for most algorithms, and they are selling for sub-$100 here in the US. Of course if you can grab a 7970 or any of the R9 cards for a good price, then do it.

Also remember to buy reference design cards if possible, and don't skimp on the PSU.
Thanks epixoip, almost every thread I have read you have given great feedback.

Well, The GPU's I have been looking at are not reference cards, but have a great price.

Maybe these are a no go, maybe they are a great deal for what I am trying to do. I was unable to locate a 7950 in the same price range. I was also unable to locate a reference card in this range. I figured there was enough space in the case/board for two of these to run and stay cool. If I bump it up to 3, 4 or 5 then I would bring them out of the case.

I am new to GPU's, im not a gamer so VLIW4 vs GCN is gibberish to me LOL. My buddies looked at me cross eyed when I build this machine several years ago and put no GPU in it. Cracking vs Gaming is more my style Wink Have any sites I should keep my eye on for good deals? Referbs are no problem, i don't care if they are used. I appreciate you time.

The problem with buying used is that you might end up with almost exhausted cards from a bitcoin mining rig or similar.
That's not really a problem. All of the cards that we run in our datacenter (except for like 8 of them) are used, most all of which were bought from retired litecoin miners who realized they couldn't get rich quick.