buying four 6950's quick question please!!

[bitcoinnoob13]

I'm planning on buying 3-4 Ati 6950's cards for mining:

1) The card requires A 500 watts..does that mean i need a 2000 Watts PSU? What am i missing here? How many watts are really needed to run 4 of these cards

2) Also requires two 75W 6-pin PCI Express® power connectors.... does that mean that i need a PSU that has eight 6-pin PCI express power connectors?? Most PSU come with 1 6-pin PCI express...How do I hook up the other 3 videocards then?

3)What motherboard will allow me to just throw the cards in there and get them up and running without having to use risers/extenders/etc?

4)is it better to put this all in a case or have an open air solution(if so, how exactly do i keep these cards cool...no fans need to be added?)

Sorry for all the newbie questions. i am trying my very best to setup a ring and its my first time.

[DrG]

You have too many questions to just jump into a 4 card rig - especially 4 6950s which would get pretty hot.

1) That 500W requirement is for laymen.  Each 6950 will use 120-200W depending on how you clock it and what coin you mine.

2) Most good PSUs will have 2-8 6/8 connectors.  If you want 4 cards on a rig, you should have 800+ and the PSU should have 4-8 plugs.  Any missing plugs you can use 4 pin molex to PCIe connectors.

3) No motherboard lets 4 cards sit in there (think about how big the board would be) except maybe one of those MSI Big Bangers.  You'll need/want to use risers unless you live in a very cold area

4) For 4 card you want open or custom made rack.  You can either run the GPU fans fast or use a box fan aimed at the open system.

I suggest you build a 2 card rig and learn from the heat issues since that's the biggest problem with mining.  Once you learn that then go on to build a 4 card rig.

[bitcoinnoob13]

You have too many questions to just jump into a 4 card rig - especially 4 6950s which would get pretty hot.

1) That 500W requirement is for laymen.  Each 6950 will use 120-200W depending on how you clock it and what coin you mine.

2) Most good PSUs will have 2-8 6/8 connectors.  If you want 4 cards on a rig, you should have 800+ and the PSU should have 4-8 plugs.  Any missing plugs you can use 4 pin molex to PCIe connectors.

3) No motherboard lets 4 cards sit in there (think about how big the board would be) except maybe one of those MSI Big Bangers.  You'll need/want to use risers unless you live in a very cold area

4) For 4 card you want open or custom made rack.  You can either run the GPU fans fast or use a box fan aimed at the open system.

I suggest you build a 2 card rig and learn from the heat issues since that's the biggest problem with mining.  Once you learn that then go on to build a 4 card rig.

Thanks for your answers. Whats the different between a riser and an extender? will a riser allow me to buy a cheap motherboard and use its regular 1x pci ports to connect my cards(pci-e 16X )

[DrG]

I believe riser and extender are used interchangeably - ie they're the same thing.

There are 1x to 16x risers, and 16x to 16x risers.  Some risers have power taken from 4 pin molex so the card doesn't stress the Mobo (critical on 5+ card rigs).  Some mobos won't allow all slots to be used (they shut down some slots if other slots are populated).  Some boards need a pin mod to detect the video card.  You need to do the research on which board to buy.  Many users have posted success stories here.  These easiest would be to buy from somebody who is trustted in the for sale section though since then you know you probably won't get a DOA or picky board.

In an field where profits change every 3.5 days or 14days or less, time is literally money - so mining sooner and less efficiently is better than latter and more efficiently (a lesson lost on BFL).