Sapphire HD7970 Reference Design

[vrposter]

I am not new to oclHashcat or JtR, but lost, cause I want to build an Ubuntu based machine running oclHashcat-plus. I am using Macs for 25 years now, but being pretty new to built your own PC. I am using my friends vanilla PC with Ubuntu for general purpose work, so I am kind of familiar with setting up.
The PC should not be too expensive, I have decided to use one Sapphire Radeon HD7970. Have been reading about "reference design" and proper cooling but I am still not sure.
Would this one
http://www.amazon.de/gp/product/B006TX48...il_1p_1_ti
be a good decision? Amazon recomends a "newer" model
http://www.amazon.de/Sapphire-Grafikkart...b_title_ce
Besides that I have to decide on Mainboard and CPU. As far as I understand CPU power is not that important, could be a cheaper one, right? The PC will only be used for Hashcat etc.

I would appreciate any help, best regards, vrposter

[epixoip]

the first gpu is the reference design card, which is what you want. i would not consider the "newer" model as it suggests.

cpu only matters if you plan to use cpu hashcat as well.

[vrposter]

Thx a bunch for your quick help. I'll order the reference design card ;-)