About GPU

[garethgtt]

Just because a card is more expensive does not mean it will be better for hash cracking. Graphics cards are designed for graphics, and just because a card is better than another at pushing pixels, doesn't mean it will be better for compute. With Nvidia GPUs, you have to ignore everything prior to the Maxwell microarchitecture, as they are not good for hash cracking. The GTX 980 is the first Nvidia card in 6+ years that is actually good at hash cracking, and in fact slaughters AMD in anything that involves memory.

Bus width matters, but it's not what you should be primarily looking at. What matters most is the instruction set and the number of instructions that can be executed per second, neither of which you will find in the marketing docs. Power consumption and cooling capabilities are important as well. We always buy reference design cards when possible as OEM-design cards are designed for gaming workloads and cannot keep up with compute workloads, especially in multi-GPU setups.

The best cards for hash cracking are, in order of preference:

1. Nvidia GTX 980 reference design


The 7990 and 6990 are omitted from this list because they are a nightmare to deal with.

So how does the GTX 980 compare to a 7990 - ive got one thats watercooled - but would maybe look at changing it to the 980 if its a lot better?

[KT819GM]

7990 is same like 2x7970, so it's ~1.6x as fast as GTX980 for single hash.

[garethgtt]

7990 is same like 2x7970, so it's ~1.6x as fast as GTX980 for single hash.

Hopefully cooling isnt an issue for the GTX980 as it is for the 7990?

[epixoip]

It's a 165W card, so no, cooling is absolutely not an issue.

[gpu_noob]

The best cards for hash cracking are, in order of preference:

1. Nvidia GTX 980 reference design
2. AMD R9 290X reference design
3. Nvidia GTX 970 reference design

I'm looking at building a four-way SLI password cracking machine and I'm debating between getting 4x of the GTX 970 reference design or the "Super Superclocked" version from EVGA http://www.newegg.com/Product/Product.as...6814487088. By making design improvements on the cooling system over their "Superclocked" model, it appears to be more efficient in terms of power draw and maintaining lower temperatures for potentially more overclocking potential. Since I plan on getting four of them, I would think that this would help keep the overall temps down within the case and extend the lifetime of the cards.

Would you still recommend the reference card over EVGA's SSC model? I'm trying to determine if the cooling improvements of the SSC model are worth the trade-off of potentially having a lower overclock potential. In either configuration, is investing in a water-cooled solution for the GPUs worth the price/performance gains?

[epixoip]

SLI is not used for password cracking, nor should it be enabled when using CUDA.

Always buy reference design, especially in multi-GPU setups. No exceptions. OEM cards are designed for gaming workloads, not compute workloads.

[gpu_noob]

Thank you for the info!

[fonzy35]

What's a Ati video card reference design? Is it card bought directly from AMD?
Is the board black..etc?

I got a MSI R9 270 gaming @ 950-1050 clock, but i can over clock it to 1150. Is it a reference design?
It does about 92,400 h/s on wpa2 @1050 clock and about 100.2 kh/s on wpa2 @ 1150 clock

Thanks in advance

[KT819GM]

Reference design means how it's cooled not it's performance.

[fonzy35]

Ok thanks.
I was just reading other post and that's what they're talking about.
Air flow going out the back of the card.