Password Cracking Rig: Build Critique Requested

A friend and I inherited five R9 290x to build a password cracking rig. Along with the cards, we have an open air frame and two EVGA SuperNOVA 1000 G2 power supplies. We created our builds independently but they're almost identical. I went with a different SSD that is $20 more expensive and half the capacity but has better performance.

Would you please critique our build? We are flexible on budget but would need to see significant performance gains to justify an increase in cost.

Requirements:
Mobo: 5x PCIe 3.0 (R9 290x), 1x PCIe 2.0 (SSD)

His build:
CPU: Intel i7-4770 3.4GHz - $290
Mobo: ASUS MAXIMUS VI EXTREME - $353
RAM: Crucial Ballistix Tactical 32GB - $320
SSD: Crucial M550 512GB - $368

My build:
CPU: Intel i7-4770 3.4GHz - $290
Mobo: ASUS MAXIMUS VI EXTREME - $353
RAM: Crucial Ballistix Tactical 32GB - $320
SSD: Samsung XP941 256GB - $390

I don't think you'll get much help here.

What do you want to know? That you overspent?

We haven't spent anything. What do you recommend?

You can gain useful info from this guy's experience.

https://securityledger.com/2012/12/new-25-gpu-monster-devours-passwords-in-seconds/

If the only use is cracking, SSD speed is likely irrelevant. So I would opt for the larger one.

mi7chy said:

You can gain useful info from this guy's experience.

Click to expand...

Thanks, I saw Jeremi's interview on Hak5 a while back but had forgotten about it. I don't recall any info about his storage or CPU in his interview and there doesn't appear to be any info about them in his slides.

SticKx911 said:

If the only use is cracking, SSD speed is likely irrelevant. So I would opt for the larger one.

Click to expand...

The difference was 500 MB/s read and write vs. 1000 MB/s read and 800 MB/s write. I should just look for bottlenecks to see where the slowest points for data flow would be.

Considering the gpu power applied, I could see it as an issue if doing a dictionary attack, but something like that seems more on the brute force lines which would be raw compute. I've only done wpa cracking for kicks back in high school so my experience is very limited, so I'm just throwing ideas out there as the topic intrigued me.

int0x80 said:

Thanks, I saw Jeremi's interview on Hak5 a while back but had forgotten about it. I don't recall any info about his storage or CPU in his interview and there doesn't appear to be any info about them in his slides.

Click to expand...

You can try reaching out to him on twitter with questions:

https://twitter.com/jmgosney

Storage I/O is only important if you use rainbow tables.