Hello everyone,

Browsing the hardware forum, I have been unable to find a thread that suits my needs. I'm looking to build a machine -- which GPU should I purchase? How many should I purchase? 6900? 7970?

I'll spend $1500. Is this a good price point? I'm willing to spend up to $2000. What can I purchase with this? Is there anywhere I can receive information that lists the exact hardware to buy?

This machine will be used to crack MD5.

Thank you in advance Smile
Buy 4xhd7990 when available.
(07-15-2012, 08:44 AM)K9 Wrote: Here:

Thanks for the links, very helpful!

(07-15-2012, 10:08 AM)Mem5 Wrote: Buy 4xhd7990 when available.

I was reading about 7990 before I posted the thread, hopefully they release it in august. With 4 of those, do you have a estimate at how many it can crack per second? I read in another thread on here that 2x7990 is ~35 billion hashes a second? Is that true?
dual gpu cards clock lower, alot is depending on this. so it will be more like 30 billion/s on md5 with -lite.
if they made desktop motherboards with 8 pcie slots than definitely 8xhd7970 than say 4xhd7990. not to mention you'd have to build a custom case using pcie raiser cables, multiple power supply, etc.. can get complicated. the biggest advantage with four dual gpu cards is that you can fit them in a standard full size ATX case using a single high wattage PSU without any customization. the trade off is it won't be as fast.

on a related note, i've been reading of bitcoin miners making the switch to FPGA from GPUs. mainly due to significant cost savings on power since they run their boxes 24/7. if you plan on a lot of hash cracking and will be running your computer 24/7, then perhaps it might be an option for you. of course you'd have to look for another app that support FPGA and the hash algorithm you want to crack.
there is no such thing, for good reasons. it might work for simple incrementing generators as in SL3 or bitcoins but not like with complex stuff like rule-engines. this might change if they actually release an OpenCL runtimes like altera announced recently, but currently.. no..