Bitcoin Forum

Hi, been following and reading for a few months, and trying to decide between getting a rig or a BFL. I have decided that I'm not interested in bringing home tons of money from all of this. I would prefer to have a bit of fun building a computer and recouping some of my costs. From reading threads of building, I've compiled a list of required items. I've left out the GPU's for the moment, as that will be an afterthought. Right now I'm interested in the cost of the machine bare bones.

List of requirements:
CPU: AMD Sempron 145 2.8GHz Single-Core Processor  ($35.98 @ Outlet PC)
Motherboard: MSI 970A-G46 ATX  AM3+ Motherboard  ($69.99 @ Amazon)
Hard Drive: Some random cheap hard drive
Memory: Crucial Ballistix sport 4GB (1 x 4GB) DDR3-1600 Memory  ($27.37 @ Newegg)
Wireless Network Adapter: Encore ENUWI-1XN42 802.11b/g/n USB 2.0 Wi-Fi Adapter  ($9.98 @ Outlet PC)
Case: Rosewill CHALLENGER ATX Mid Tower Case  ($49.99 @ Amazon)
Power Supply: Corsair TX Series v.2.3 750W  ($100 @ Newegg)
Fan: XIGMATEK Dark Knight II SD1283 Night Hawk Edition CPU Cooler ($35 @ Newegg)

Total: $325

Can anyone find any fault in this. It'd be great if there were some place to buy a cheap pre-built computer minus GPU's though, and just add them myself. I plan on just loading a Windows OS on this, as I have no experience with Linux/Ubunu/don't see the 'huge' benefit from these, I'm a mac user.

How many GPU's can fit within a single computer? Can I use up the slots within the case and then have cable leading to more?

I could get:
7970 x 2
5850 x 6
5830 x 2

Can anyone post any comments/criticism/any better recommendations?

Depending on your GPUs You night want to re-think the case - open air setup should give you better cooling.

I have not used this motherboard personally (Using asrock 970 extreme4) but I heard they are ok as long as you don't exceed 3 GPUs - some hacks are required if you do

Hope that helps you a bit

That's pretty cool. I might take some of my BTC profits and try some mining...not sure yet.

Would there be any issue buying some somewhat powerful desktop off ebay/craigslist and just swapping out the GPUs?

I'm not against open air. I could just build one of those milk carton setups. I have no idea about motherboards, I'm going in blind.

It goes back to my question though, can you 'theoretically' have as many GPUs connected to a motherboard as it can handle, regardless of the pin connections?

I would recommend you get a Kilawatt electricity usage meter. You can get one on Amazon for about 16$ and it will let you see how many watts that rig is pulling. The GPU cards will be using much more when they are all mining than when they are sitting idle. How about drivers for the cards? I am not sure, but are the drivers the same for 7xxx and 5xxx series? I think I read someone managed to make a combination like this work before, just mentioning it as something you might want to look into first.

i would look at the  cooler master HAF 912

new egg part number : N82E16811119233

it should have more than enough room for your future video cards .

also the poster who mentioned the number of video cards a mother board can support should be seriously considered .

while some mobo have 4 pci e headers on  them it does not mean  it will support 4 cards . so some research into the motherbaords that work properly with 4 or mores cards would probably save you some future headaches

and you may want to bump up the power supply to a 1000 aswell   just to ensure you have the power run those 4 cards .  coirsair series is fine .

and if you plan on using the system for anything else i would get rid of that sempron .    but thats a personal prefence .

also if you plan on keeping your wallet on this system invest in a backup  either a internal hardrive or a external harddrive with back up software.

If you have the inital capital, why not go for a FPGA instead? better investment if you're able to get one right away & can afford it. Electricity will not be an issue with it either.. Plus, some have red LEDS! :)

Are there any FPGAs that you would recommend?  How about ones to stay away from?

I haven't purchased one, but this is a good site for info: http://bitcoinfpga.com/

As far as I know, there's only BFL (ButterFly Labs) and Avalon currently planning to ship ASICS to end-users.

There's also ASICMINER in which you can invest. They're using ASICS to pay their investers with dividends.

Edit : you were talking about FPGAs, my bad.. :)

Pretty sure the drivers are different... but interesting idea mixed cards on one MB.   I read that you can mix them on a MB for multi-heading, but you can't link them with Crossfire tech for gaming.  But I haven't seen a clear tutorial/example of someone actually doing it for mining vs. gaming.

also a good read can be found in

the bitcoin talk forum   bitcoin/mining/hardware/motherboard of choice for 6 or more GPU's

some good reading there.

I just ordered 2x 7970 from gigabyte with 3GB. The only downside is that certain newer batches are voltage locked so no overclocking. You will need to mine in a pool for bitcoin or have a look at some of the altcoins. Even litecoin is getting difficult at the hashrate you will achieve with these setups. Best of luck.

well, gpu mining is barely profiable now, but once bfl launches, it will use too much electricity. also, use linux. it's free. however, the bitcoin wiki page on mining hardware is good, as is bitcoinx[.]com/profit .

dont forget if u can have good source of used GPU that also will bring down your cost.

The real issue once you consider building something with 3+ GPUs is heat dissipation. Many motherboards support 3 GPUs and many cases can fit them. There are also a good amount of PSUs out there to power them, but cooling 3x high end GPUs is a completely different matter.

For reference, there is a thread going of someone who managed 4x 7970s in a custom built case, but 3 of them get throttled due to overheating.

But maybe you live in Iceland or Canadia and can leave a rig running in a garage. :)

MTV HEHE

how many hashes u got with this rig?

Building a GPU rig will only offset your costs. Breaking even is a thing of the past, unless you're not paying for power and have a crazy cheap source for used GPUs.

Rig of VGA is out.!!!
I will make rig of FPGA Lancelot or Icarus.
Small motherboard with CPU and RAM, good ATX supply and 8 pieces of "Lancelot" .
Small consumption, high power in Mhash/s

How interesting ???

You could opt to build a Litecoin mining rig instead of a Bitcoin miner, though. A single ATI Radeon 7950 will net you approx. 630 kH/s mining LTC, which according to http://dustcoin.com/mining will net you approximately $199.13 in profit per month minus your cost of electricity. This is as of Tuesday April 30th, 2013 at 3:45 AM (GMT -4) (just for reference). If you go over to https://btc-e.com/ you can find the current exchange rate for both BTC and LTC, and some other smaller derivative coins. Right now LTC/USD is at $4.16. I bought $20 of it a week or so ago back when it was $2.59. It's considerably appreciated since then, and lots of people expect LTC to go up and up.

So, basically what I'm saying is, LTC is more profitable to mine than LTC even without assuming an appreciation in value, and an appreciation in value is highly likely when Mt. Gox starts trading LTC. A lot of the people in the BTC-E trollbox (the chat box on the right hand side of BTC-E's website), and also in /r/litecoin and /r/litecoinmining on Reddit speculate that Mt. Gox will begin trading in LTC. Mt. Gox has actually commented on this themselves in a press release, saying something about their plans regarding LTC. This caused the recent price jump which happened almost overnight from $2.50 to over $4 a coin amid the rumours.

Personally, I feel that in the coming months a lot of Bitcoin miners who have GPU based Bitcoin miners will switch over to Litecoin because they will start to see the decreased profitability of mining Bitcoin with a GPU especially amid the new FPGA/ASIC based Bitcoin miners which are much more energy efficient and have much higher returns on investment.

As per your specs that you posted in your first post, I too am trying to come up with a suitable build to get this miner of mine up and running. My budget right now is approximately $1000, so I'll only be able to afford one 7950 (or other GPU that I decide to go for instead; but I'll probably go for the 7950) initially, on top of a decent 80-Plus Platinum PSU and also a Phenom II X4 965 in lieu of the Sempron (I had that in there too, but I ultimately decided against it because I want to use this as a fileserver as well, and I want to possibly be able to resell it later as well).

Here's my wishlist so far on Newegg: http://secure.newegg.ca/WishList/PublicWishDetail.aspx?WishListNumber=22932806

Feel free to take a look. It's based heavily off of http://www.cryptobadger.com/2013/04/build-a-litecoin-mining-rig-hardware/ which is a /very/ well written (in my opinion) and recently written guide on how to get started building a good, decent mining rig.

The only things I worry about are the following: I worry if the PSU is worth it/is overkill for the price/whether I should be going for a less-efficient less-expensive PSU but of comparable wattage. I wonder how much it'll really save me at the wall in terms of electricity costs. I also wonder if I should indeed be springing for a Radeon 7970 instead of a 7950, but all of the sources I've read say that the 7950 is the way to go in terms of the hashrate/$ ratio.