Require a little help here.

[SolidSnake]

Thanks all for the infos, really appreciate.

Yes I will start with only budget stuff and take the time to test/learn password cracking.

When I'll have more money to invest I'll go for a server case with 8x pci slot mobo so I can add gpus gradually.

[rurapenthe]

The general rule i use is that if it has 2 (or more) fans, usually centered and advertising "turbo, superfan, ultra-fan, ultra-cooling, super-cooling, twin-frozr, ice-whatever" etc it is NOT reference.

If its MSI and says "Gaming Edition and/or LE" avoid it like the plague.

Finally, the reference tend to be more expensive than the non-reference cards.

[fonzy35]

Well my MSI R9 270 OC Gaming, on only one connector(75 watts) , with after burner it will takes the overclock @1050MHz easily
and it's doing 92,300H/s wpa in open case, compare to 69737 H/s wpa @ 900Mhz
http://golubev.com/gpuest.htm

No offence but you don't have to bash everyone video card, because we don't buy "Reference cards"

Works with Oclhascat64 1.31 and 1.32

It's energy efficient compare to the 270X (watts burner)

[undeath]

No offence but you don't have to bash everyone video card, because we don't buy "Reference cards"

nobody bashed anyone. This is a thread about a mulit-gpu cracking server, not and end user PC. For such servers non-reference design cards are simply unsuited.

[epixoip]

Right, in systems with only one GPU a reference card might do okay. But the fact that the 270 is only a 75W card is the real reason why it's able to cool itself well. You realize that's nearly half the power draw of a CPU, yeah?

[fonzy35]

my cpu draw 77w (full Load)
I3770k
i was just making a point , because i compare the 270(150watts) and 270X(225watts)
I returned the 270X to the store

the 270X pic up about 102kh/s(wpa2) easily run hot up to 88 C (watts burner)
the 270 pic up about 92kh/s(wpa2) easily run less hot 73C (energy efficient)

I don't think its worth the extra cost of Video Card $$ and extra cost in watts for a 10 kh/s gains

i order another MSI r9 270 to crossfire it, I'm expecting a good 184,000 - 200,000 H/s combine for to low energy card

I wish they were all reference card , but there not.. :-)

[Flomac]

The 270 and the 270X use the exact same chip with 1280 shaders. The 270 has a TDP of 150W and the 270X of 180W, but if you clock them at the same rate, they will perform identical and use the same amount of watts. If one card gets 15 degrees hotter, well, the cooling systems of graphic cards differ a lot and the poor ones show under extreme stress like an oclhashcat run.

The reason why the other guys perfer reference design is the fact that reference design cards use an radial cooler while OEM designs use axial coolers. Hence more effective the axial cooler just spins a lot of air around and does not care where it came from and where it goes to. The radial cooler tries to get the hot air out of the system at the back of the GC. If you stuff two GCs with an axial cooler next to each other the one with its cooler next to the back of the other is heating that card up. If you can leave a lot of space between those two and you bring a full package of air flow into the case then these cooling solutions might even work. But with four or even eight cards you have no other chance then using reference cards with a radial cooler.

[fonzy35]

The 270 and the 270X use the exact same chip with 1280 shaders. The 270 has a TDP of 150W and the 270X of 180W, but if you clock them at the same rate, they will perform identical and use the same amount of watts. If one card gets 15 degrees hotter, well, the cooling systems of graphic cards differ a lot and the poor ones show under extreme stress like an oclhashcat run.

The reason why the other guys perfer reference design is the fact that reference design cards use an radial cooler while OEM designs use axial coolers. Hence more effective the axial cooler just spins a lot of air around and does not care where it came from and where it goes to. The radial cooler tries to get the hot air out of the system at the back of the GC. If you stuff two GCs with an axial cooler next to each other the one with its cooler next to the back of the other is heating that card up. If you can leave a lot of space between those two and you bring a full package of air flow into the case then these cooling solutions might even work. But with four or even eight cards you have no other chance then using reference cards with a radial cooler.

it make sense for more then 3-4-6 cards, thanks for that good explanation

My case is open when i do oclHasdcat64
My second Video Card arriving tomorrow, i probably going to have to put a extra CFM case fan, for the front intake.

Thanks

[Flomac]

Proper airstream happens in closed cases, not in open ones. If you remove the front cap of a hairdryer it gets less effective. Same with fans in cases, the air streams through if there are fans in the front and back. Open cases only prevent you from areas where hot air gots stuck and heats up more and more. But for effectively cooling GCs a case should be closed.