Bitcoin Forum

Hi guys, i'm gonna setup a mining rig. Here's my configuration. let me know if i need to change something.


Mobo: Asus crosshair v formula
cpu: Amd bulldozer 1850 black edition
gpu: 4 x sapphire 7950
psu: Real Power Pro 1250W (cooler master)
ram: 8GB


tell me if any of these is not compatible or have any other issue, i've ordered the gpu but i need to buy other stuff. mobo+cpu+psu+cpucooler, i'm getting these in a bundle from someone i know.
I think that 1250W won't be enough to run all 4 of these. anyways, tell me what do you think about this.

I would reccomend mining an scrypt coin, also your cpu does not need to be fast, nor do you need so much ram

a cheep semperon 140 will be fine

you forgot riser cable , at least 1 powered for 4 cards.

you won't cool 4 cards in a case.

You can get a cheap cpu and ram, and cheapest mobo that takes 4x pci-e.
The power draw should be under 900w.

i've underclocked (and volted) my cpu, getting around 700W with 2 7950..

Why would you suggest that, rather than just mining bitcoins? I only ask because I'm just about to set up a similar system for bitcoins. If that sort of rig is better for other coins, I'd appreciate the reasons why so I can modify my purchase if needs be.

Thanks

Bad luck we get a lot less with 2 7970  :P

I've to say it's the power draw from from the wall, i don't know how much power the psu actually gives to my system
maybe i cranked up those cards too much, i do 1400 khash/s with them
and it isn't my final setup, i've too much fans right now :P

Have a look at https://github.com/litecoin-project/litecoin/wiki/Mining-hardware-comparison for an overview. I would suggest mining scrypt based coins at the moment when you want to invest in GPUs.

You don't need 1250W for 4 7950s. 850W should be sufficient with a low-powered CPU, but you can go up to 1000W if you want to be safe. Each card shouldn't ever pull more than about 180W unless you're overvolting them significantly. I undervolt my 7950s by about .3V, which saves a bit on electricity. They're still overclocked; I get about 635khash on one and 650 khash on the other.

There is a difference between power supplied by a PSU on 12V lane and total power a PSU can supply, and if it says on a sticker that PSU has 1250W of power it means that the PSU will give you less power on 12V lane that that. Also runing a configuration that will draw 95% of your PSUs 12V lane will most likely get it killed very fast and even if not, will result in worse efficiency and higher temperatures. For example a PSU with efficiency of 80% and with system using 600W of power will use 750W while the same system with a PSU with efficiency of 90% will use 666W which gives you 60kWh less per month.
So no - buying the cheapest possible PSU and hoping it will be enough is not a good idea.

I certainly understand that, and I wouldn't recommend running up close to your PSU's limits. However, people significantly overestimate the power needed for current hardware, and have for several years. The most important thing, which you eluded to, is the amperage on the 12V line.

I never did, and never would, recommend buying the cheapest PSU available, especially an inefficient one. That's a recipe for costing you a ton of money in power consumption and fried hardware. However, I believe all of these recommendations for 1250W+ PSUs are misplaced.

Interesting rig. Im interested in getting a bigger rig as well. How are you going to handle the heat?

if you build this for mining rig only

you better get a cheaper CPU & RAM

Hi, guys, thanks for replying.
well I'm using 8gb of ram i'll be making another system for mining. so i'll just split it, i'll use 2x4GB.
and i know about the mobo and cpu, what mobo do you guys suggest? The problem is, i can't find a good gigabyte or MSI board here which has 4x PCie16x.
and i know a riser cable is a must, i already know about that. and i'm not using a chasis for this system. It'll be open, i'll make a custom table/case for this later.
I just wanted to know if i use 4x 7950 on a 1250W supply (http://www.coolermaster.com.au/product.php?product_id=3143 (http://www.coolermaster.com.au/product.php?product_id=3143)), will it be enough. cause it'll be running 24x7.

I built a mining rig with 3x 5870 and a 7850 running on 970a chipset and Sempron 140 unlocked with 4 gigs.  Heat sucks.

Hey are you buying your cards brand new?

ifso you might want to check the 7970s as they are not much more expensive in the states

yeah i'm gonna try 4 cards on this system. i might make a new system in the future on which i might use 6 cards but that's another issue.
anything else i need to know about it?

I would stay way from PSUs with multiple 12V rails unless you know what you're getting into. This Corsair 850W (12V@70A) (http://www.newegg.com/Product/Product.aspx?Item=N82E16817139015) or 1050W (12V@87.5A) (http://www.newegg.com/Product/Product.aspx?Item=N82E16817139034) should be sufficient for 4 7950s and a low-power CPU. If you insist on that Bulldozer CPU, go ahead and pick up the 1050W. Unless my calculations are way off, the 87.5A on the 12V rail should be more than enough.

If you want to run all four cards on a single board, just get PCI-E 1x to 16x risers. It won't hurt your mining and makes choosing a board a lot easier as most high-end boards have 4+ total PCI-E slots. Heck, even mid-range boards have 4 PCI-E slots.

I would definitly suggest running a scrypt coin, overall you will get more return.

whats wrong with 12V Rails???? Oo

scrypt coin??

Litecoin, FeatherCoin, CHNCoin and similar are scrypt based coins.

See this: http://www.coinwarz.com/cryptocurrency

Here's a good friendly CHNCoin pool: https://pool.chn.co.in

There's nothing wrong with 12V rails. Such are required for powering a computer. However, having multiple 12V rails splits the amperage between different sources, meaning you will need to be aware of how many amps are on each rail and how many amps are available. If you don't know what each piece of your hardware draws, that can cause problems. Having a single 12V rail means you don't need to worry about the balancing issues.