A Radeon HD 6990 for hash cracking. Good or bad idea?

[epixoip]

Completely disagree. As stated above, we had 24x 6990 and we couldn't get rid of them fast enough. The only card I've loathed more than the 6990 is the 295X2.

The 280X is just a re-branded 7970 that is only sold as an OEM design. And as you should know by now, we never recommend OEM design cards. Instead of recommending a 280X, you should recommend a reference design 7970.

[Forezza]

The issue with the newer cards is that they're quite expensive in my country. The reason being is that I live in NZ and the graphics card market is small enough here that people will still buy the better and more recent graphics cards for gaming. There is only one auction site and it has 300 listings (mostly filled with shitty, old cards). I saw a R9 270 go for $150 US the other day. Buying internationally is always a possibility although decent shipping is upwards of $50 for the larger cards if the seller would even ship internationally.

This is why I'm opting for the older cards that nobody particularly wants although I'm also wondering if there may be issues later on with compatibility with drivers and so on.

[10fi]

Completely disagree. As stated above, we had 24x 6990 and we couldn't get rid of them fast enough. The only card I've loathed more than the 6990 is the 295X2.

Hi,

what is wrong with 295x2? Looks perfectly good - 1 PCB, 2 fast GPU, WC. Apart from power drain, that is.

[Flomac]

The temp limit is verly low with 75°C, the card will overheat under heavy load like Hashcat, start throttling and all the theoretical power is gone. Except the cooling is WAY better then standard.

[10fi]

The temp limit is verly low with 75°C, the card will overheat under heavy load like Hashcat, start throttling and all the theoretical power is gone. Except the cooling is WAY better then standard.

Thank you for that, haven't been aware of such ultra low critical temperature.

I guess that would take some research why it is so, and probably the BIOS modification would be needed here - what obviously could lead to problems with RMA and bricked card in the end.

Plus, I'm bothered about the extra investments in power supply and electricity bills - I guess that it is important if we are building something near 24/7 or rather from time to time password cracker.

Regarding the 7970 - I guess it can be only accepted as an option if you have somehow soundproof room in which the machine will operate. I had 7970 (with some kind of "ultra silent" non reference cooler) and it was hard to sleep in the room behind the wall when I did computing on it :-)

Not exactly sure why we talk only ATI/AMD - what would you guys say about the nVidia propositions, like 970 or even a 750Ti?

[Flomac]

That's the problem with the 295X under stress (comparable to hashcat):
https://www.youtube.com/watch?v=YCIZJW-aPaE

There is a serious design problem with the voltage regulators which reach up to 107°C. They are neither properly designed or cooled for these loads. Look in the middle of the card:




And how it's done right (1-slot ASUS ARESIII):




Buying Nvidia for Hashcat is clever, GTX970 has a good price/performance value, the GTX980 very well and the GTX960 is great value for half the 980-performance. It outperformes the 750Ti clearly and is merely more expensive. All these cards run much more efficient than comparable AMDs, so less power and less heat.

The 390X might be a game changer again, although I read it'll come with a stock water cooler.

[10fi]

I'm amazed about such an expensive card being messed up so badly. Thanks Flamac for such verbose info.