Is it possible to use 4 X 6990's?

[jakkeyter]

Why does almost everybody only use 3 6990's?  Is there any limitation that would prevent four?

I have the following rig in mind.  Please advise if this will do or am I missing something.

4 X HD 6990
MSI 890FXA-GD70
2 X Corsair TX750V2
AMD Athlon II X3 450
Lian-li pc-V2010
2Gb DDR3

I believe under Windows this won't work, but it should in Linux?

[1714920500]

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[1714920500]

1714920500

[SomeoneWeird]

Should do, just be careful you don't run the power from the same line as the rest of your house, ie toaster, oven etc.

You MIGHT need 2 1000v PSU's, I don't have a 6990 but i know they drain alot of juice.

[itsagas]

and 4 of those suckers in one rig is HOT, with a capital H. 

Be prepared to cool them.

[SomeoneWeird]

and 4 of those suckers in one rig is HOT, with a capital H. 

Be prepared to cool them.

Yeah, If I were him i'd get PCI extenders and stick waterblocks (+ like 10 fans) on each one.

[jakkeyter]

Thanks

So except for heat there are no other limitations, eg. O/S (Linux will be able to run these?)

BTW, whats the biggest single slot Card available?

[SomeoneWeird]

Thanks

So except for heat there are no other limitations, eg. O/S (Linux will be able to run these?)

BTW, whats the biggest single slot Card available?

Yes, linux can, but windows won't be able to.

[piggybank]

BTW, whats the biggest single slot Card available?

Don't know which is the biggest single slot card, but does it really matter? The heat output of any decent card is so high that you really cannot slot them onto the board without getting crazy high temperatures.... even with lots of additional fans!

Much better to use risers/extenders and then just place your cards further apart... in which case single or double slot, it doesn't really matter.

[eazolan]

I'm curious to see who else is planning on venting their mining rig to the outdoors.

According to the wiki page, that's a max of 375w per card. 1500w just to power the cards.

That's converting 1500w of electricity to heat, 24/7. It's like turning on a blow dryer and just letting it sit there.

Water cooling them will just move the heat from the cards to the radiator. (water pumps also require power and generate heat.)

[SomeoneWeird]

I'm curious to see who else is planning on venting their mining rig to the outdoors.

According to the wiki page, that's a max of 375w per card. 1500w just to power the cards.

That's converting 1500w of electricity to heat, 24/7. It's like turning on a blow dryer and just letting it sit there.

Water cooling them will just move the heat from the cards to the radiator. (water pumps also require power and generate heat.)

Yes, but water cooling is alot more effective and efficient for something like this, sit your computer outside your bathroom or something and then it can heat that up

[Danijel Habek]

One could always try to plug those water blocks to the floor heating system, and save some radiators and water heaters...

[bcpokey]

I'm curious to see who else is planning on venting their mining rig to the outdoors.

According to the wiki page, that's a max of 375w per card. 1500w just to power the cards.

That's converting 1500w of electricity to heat, 24/7. It's like turning on a blow dryer and just letting it sit there.

Water cooling them will just move the heat from the cards to the radiator. (water pumps also require power and generate heat.)

Well the stock TDP is 375Watts, you will get terrible hashing rates stock though. Overclocked it can do even more wattage. In fact the ATX design limit is 375Watts to the card (75 + 150 + 150) which is closer to 450Watts from the wall per card (max).

Just dig a hole in the ground and throw your PC in there. Best cooling solution

[twitcoins]

> sit your computer outside your bathroom or something and then it can heat that up

I think you'd rapidly find that a 1500w load would turn a bathroom into a sauna.  Plus, you know, all that moisture.

[marcus_of_augustus]

Yes you can. But you will need to separate the cards somehow to stop the "stack" building up too much heat on the GPUs in the center.

Also you will need to re-route power bypass around the mobo rails or else you will start frying mobo power rails and connectors.

Lucky there is a solution!

https://forum.bitcoin.org/index.php?topic=6128.0

These PCIe ribbons lets you move cards away from each other to run cooler and also has option with power cores broken out to connect straight to molex power connector .... it bypasses around the mobo power rails ... you'll be safe now.

[dingus]

One could always try to plug those water blocks to the floor heating system, and save some radiators and water heaters...

Someone already has done this. Search the forums.

edit: Here is the post I am referring to. http://forum.bitcoin.org/index.php?topic=3707.msg53879#msg53879