Bitcoin Forum

I have come across a sales ad for someone offloading their mining equipment (not sure what the reason) for very good prices.

Here is the equipment available:
MSI 870-G45 Motherboard + AMD Sempron 130 CPU + CPU Cooler
4 x Sapphire HD 5850
various PSUs from 400-600w

If im correct, the mobo can only support 2 pci-e cards, correct? Or can the basic pci slots operate a 5850 card (ie: more cards per mobo)

Assuming only 2 cards can be used, it would be roughly:     700 Mhash/s (~350+ per card)      450w (~150 per card)      ~$200    for a single machine setup.   Electricity costs $.09/kwh

based on calculations, the ROI is about 250 days, which isnt particularly bad. However, this assumes that SIC devices dont come out for at least a few more months, which is arguable from both sides.


Is this worth the investment and time, will there be much resale value in ~6months?

You can't use a GPU in the reg PCI slots, but you can use one in the PCIe x1 slot with a riser cable.

I would be wary of investing any money into a GPU rig at this point. Current GPU rigs can still operate at a profit, but I doubt its worth it to put money into building a rig.

Yes, your profitability calc says you should receive a 100% ROI in 250 days, but that does not take into account ASICs. Regardless of your opinion on the who's-who of ASIC manufacturers, SOMEONE will deliver ASICs in the next 2-3 months, and then your rig will be mining at a loss.

You might be able to sell your hardware for close to what you bought it for 6 months from now, but that's assuming all of the hardware still works. You're already talking about GPUs that are 2 years old, and mining really pushes them to the limits. If one of your GPUs or your PSU or any component fails, you're now stuck selling that broken piece of hardware at a loss.

TL;DR I would not recommend buying a GPU mining rig at this time.

nicely put, thanks for verfying my thoughts. Ive made a lowball offer and also offered to host the equipment if interested (i have a few places in mind where i could get cheap electricity or otherwise use the rig for winter warmth)

You're too late. Difficulty is skyrocketing, rewards are halved. Don't bother. Less people mining = more profitable for me.

A low risk budget rig is probably still worth it if you can afford to run the rig off your existing income and are counting on the price of bitcoins to continue appreciating. It's just a matter of finding a pool that a budget rig will make enough to qualify for payment from.

Buy the same amount of BTC that this machine would cost.  In one year I think you will have more value.

Agreed.  Though building rigs is fun, the likelihood of getting your money back at this point is pretty slim.

Depends on your electricity price, $0.09 is pretty low.

I'd need to see BTC $16 before I'd break even.

I'm leaning toward buying an FPGA. (but like everyone else wonders if I should wait to see if ASICs will turn up)

Last winter, I could justify my mining rigs being run constantly and didn't have to consider much in the way of electricity costs because I turned off all heating devices, and turned on a single box fan to spread my GPU heat around the house. It kept everything nice and toasty (a feat that would have my heater running 24/7) and wasn't an inconvienence (actually, at times we did have to open windows to let some heat out). While running the heater full time wouldn't have been as much electricity, it still would have accounted for most of what was spent on electricity. If you can get a cheap rig and use it to not have to use someone else (in this case a heater), then it may be worth it. I've seen people use their rigs as clothes dryers (careful of the moisture though) and using them as paint dryers (when doing really fine work, a lot of artists will use hair blow dryers to speed up the drying process so they can continue painting right next to what they just painted). I've seen people use rigs as nightlights too... It all depends on what you can eliminate with a GPU setup.

Every new miner should just wait and wait and wait for the ASIC, so my ROI on my gpu farm is better that way, still 20-25gh vs 3000000 diff yeah i say this is the whole point of the ASIC vendors...they keep big gpu, farms becourse no new miner will throw in $10k - $15k to begin a gpu farm at this moment whaaaaaaaaa ;) ;)

Not worth starting GPU mining now.  We're on the cusp of ASICs coming online.  It's like starting CPU mining when GPUs were taking off.  Difficulty should be at least 10 times higher than it is today in 6 months time.

Ignore the people who recommend not mining because they smuggly state it's just more profit for them.  It's cheap trolling.

But it -does- mean I'll make more money if other people don't start mining too. Difficulty is too high and rewards are too low as it is.

I'd get 5830's instead of 5850's as well.  Your 5830's wouldn't depreciate in value as much + every single one I've ever had can run at at least 750 core @ 0.95v.  

You can save even more wattage by totally removing their fans.  If your ambient temperature is 74o or less they won't overheat.  Keep the heatsink on, ofc (but not the shroud).

I don't think some random 400-600 watt PSU could power 4 5850's, either.  Even with your OS on a USB stick.  It could (*600w), however, power four 5830's at 0.95v without fans!

(I just checked, mine is pulling 37 amps for 250mhash/s, 750/135)

that's really bad reasoning, because for the same amount of money, you can just buy bitcoins, without the hassle of setting hardware up.

+1 for the post above; if you are getting into GPU mining at this stage ... you are gonna be SOL in a month's time. Now if you feel you can get everything you spent in BTC in one month from mining (using pools / solo mining) then it may be worth it to you simply just to have the computer hardware. But IMHO, you are better off simply buy BTC or playing the ASIC waiting game.

I am in a similar situation. I'm in the middle of building a GPU mining rig, but I'm also going to use it for gaming as well. Plus, I need a new computer. My ROI is a big longer, but I have free electricity, so I'm going with it.