Bitcoin Forum

I have a friend who owns a lan house with 10 computers. Each computer has a nVidia 7600GS (512mb ram I think).

He pays a fixed price for electricity so electricity cost is out of the equation.

His idea is to use those computers to mine while the Lan House is closed. It is worth it and how much profitable it could be?

Will that hardware even mine? I thought it was too old. You could try a few different miners, or see if it is on the hardware comparison wiki.

Problem #1: this is an nVidia card
Problem #2: this is an entry-level nVidia card

Let's compare with an nVidia 8600GT. A 7600GS is a (much) slower card than the 8600GT, but let's keep things simple and assume the 7600GS will perform on par with an 8600GT.

An 8600GT has a hashrate of ~5Mhash/s.

http://www.alloscomp.com/bitcoin/calculator.php (http://www.alloscomp.com/bitcoin/calculator.php) tells us that a 5Mhash/s card will generate 0.10 bitcoins/month. That's 50 cents. Per month.

So your cluster of 10 computers will generate no more than 1 BTC PER MONTH. Maybe you don't pay extra for electricity, but by any measure this is a monumental waste of time and resources. The 'profit' of 1BTC/month will not be enough to cover the extra stress your hardware is exposed to (increased chance of hardware failure).

Bottom line: it is not worth it. Even if you don't pay for the extra electricity, this is a losing proposition because you'll most certainly experience a higher failure rate due to the stress of mining.

Decide for yourself whether 1 BTC/month ($5/month) is worth the potential loss. And remember, this analysis is based on an 8600GT; your 7600GS (assuming it can even mine at all) will be about 1/2 this speed.

I also think his calculator is assuming 24/7 mining, so you won't even get 1 BTC/month :(

Good point.

Thanks Epoch for the detailed answer.

Your friend should upgrade each machine to a modern video card, and THEN mine on them!

Pick up a brand new 5850 for each computer, overclock them so you're getting at least 350 MH/s on each, and you've got 3.5 GH/s.  Then he'd be making around $300/month.

Upgrading to suitable Radeon cards makes sense. It's an investment in gaming hardware for the daytime activity as much as it's an investment in mining equipment for night-time usage. The upgrade would make his "LAN-house" more attractive to his gamer customers, and the cards would probably pay for themselves in less than a year with mining.

What kind of LAN games can you even play with those cards? You must be into some serious retro gaming there :)

I mine on gaming computers, using 5870 cards. Especially when crossfired, those can run pretty much any game nowadays.

Right - as long as the processors/ram specs weren't terrible, they could play any of the latest, including BF3.

The concept is sound, though the calculation assumes 24/7 operation for mining. Still, with 1/3 time allocated to the LAN house and 2/3 dedicated for mining, that's $200/month. Electricity is already included, so mining is pure profit ... at least once the capital investment on the Radeon cards is recovered.

Also remember that, come early December, mining profits will drop (perhaps significantly) since the block reward gets cut in half.

With full specs of the gaming computers, people could recommend cards that would better fit the overall performance and be suitable for mining.

If the mboards are PCIe this will work.  They may be AGP thu ;)

I have been using 7600GS (AGP) in the past.
No CUDA, no OpenCL. Totally useless for mining.
If the Machines have PCIe, upgrading to a modern ATI Card would be reasonable.
As a free Solution, mining some alternative Coins like Litecoin, Solidcoin on the CPU could make Profits.

 Each computer has a nVidia 7600GS....

Seriously? Just junk that crappy hardware, seriously!