Bitcoin Forum

http://pcpartpicker.com/p/RxZm (http://pcpartpicker.com/p/RxZm)

CPU: AMD FX-6100 3.3GHz 6-Core Processor  ($89.99 @ Microcenter)
Motherboard: MSI 990FXA-GD80V2 ATX  AM3+ Motherboard  ($164.98 @ Outlet PC)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory  ($59.97 @ Outlet PC)
Storage: A-Data Premier Pro SP600 32GB 2.5" Solid State Disk  ($39.99 @ Newegg)
Video Card: Gigabyte Radeon HD 7950 3GB Video Card (3-Way CrossFire)  ($297.98 @ SuperBiiz)
Video Card: Gigabyte Radeon HD 7950 3GB Video Card (3-Way CrossFire)  ($297.98 @ SuperBiiz)
Video Card: Gigabyte Radeon HD 7950 3GB Video Card (3-Way CrossFire)  ($297.98 @ SuperBiiz)

Power Supply: PC Power & Cooling Silencer Mk II 950W 80 PLUS Silver Certified ATX12V / EPS12V Power Supply  ($137.98 @ Newegg)

Total: $1386.85

Nothing is absolute yet. THe motherboard I chose because it looks as though I may be able to put 3 7950s in without risers, and have enough space between to keep them kind of cool. No case yet as it will be open air, and if /when I do get one its prolly going to be a COOLER MASTER HAF XB RC-902XB-KKN1. I am going with a higher end cpu so maybe itll be a little useful after its mining days, and be somewhat desirable on the bay if I decide to sell it. Im open to comments and suggestions especially for the cards- I am wanting a 7950 thatll be able to do 625-650+ K/Hs each (for LTC), is reliable, and somewhat quiet.

Consider to buy 1200W PSU. You config is likely to drain 1000W~1100W if you will be able to cool it well.

I second the 1200w power supply. I tried running a 3x6990 rig with a 1200w power supply and even then, after adding on the fans, it ended up being too much. Ruined the PSU. Can't speak to the CPU or RAM choice, since I know LTC uses them in a way BTC doesn't. I don't have as much experience with LTC as I do with BTC.

EDIT: Looks like the 7950 is quite a bit more power efficient than my 6990s, so you might be able to get away with a smaller PSU. Still, I'd say it's better to have a little headroom if you can afford it...

Go with the AMD Sempron proc. It's only $30 at microcenter. The 6100 is going to be taking extra power and generating extra heat. When you want to get out of mining, go buy the better proc. You can use the same motherboard. AM3+ has a good upgrade tree.

Personally, i think your spending too much money on the CPU, mobo, and ram.  Not saying you can find those exact products cheaper, I'm saying you can find different products that are cheaper that will do the same thing.  (as long as you are only using them to mine bitcoin) You could also drop the SSD and just use a flashdrive.

***Earlier I mentioned that the rig would be used only for LTC- changed mind on that. The rig will be used for some BTC, LTC and other ALT coins.***

Another option I am considering is this:

http://pcpartpicker.com/p/RD3D (http://pcpartpicker.com/p/RD3D)

CPU: AMD Sempron 145 2.8GHz Single-Core Processor  ($35.98 @ Outlet PC)
Motherboard: MSI 990FXA-GD80V2 ATX  AM3+ Motherboard  ($164.98 @ Outlet PC)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory  ($59.97 @ Outlet PC)
Video Card: MSI Radeon HD 7950 3GB Video Card (4-Way CrossFire)  ($309.99 @ NCIX US)
Video Card: MSI Radeon HD 7950 3GB Video Card (4-Way CrossFire)  ($309.99 @ NCIX US)
Video Card: MSI Radeon HD 7950 3GB Video Card (4-Way CrossFire)  ($309.99 @ NCIX US)
Video Card: MSI Radeon HD 7950 3GB Video Card (4-Way CrossFire)  ($309.99 @ NCIX US)

Power Supply: SeaSonic X Series 1250W 80 PLUS Gold Certified ATX12V / EPS12V Power Supply  ($254.99 @ Amazon)

Total: $1755.88

add to this one powered riser.

HDD will be a used one I have laying around, same for DVD drive.

I would say get risers for all the cards as there is going to be some major heat on the middle card(s) being so close.

Do these cards need powered risers?    I'm about to add a card to my rig and only got regular 16x risers(installing this weekend).
I thought that the direct PSU -> GPU power connect allowed a normal riser.

btw i'm no expert - have only built 1 ltc rig recently and still learning.

I have heard that if you do more than 3 cards on a mainboard that you will want to add a powered riser. Its just to cut down on the amount of current running through the mainboard- some mainboard connectors have melted because of too much current.

You could dump the 3rd card and get 2 7970's.. they each can pump out around 660-710 or more depending on card, unlocked voltage and how you feel about overclocking.. would prob save you about $100

I ran 3 7950's on a 1200watt psu for ages