I nearly went Office Space on my mining rig.
For a brief period of time I had three GPUs mining at 37.1 MH/s, so I tried to hook up the fourth and go for ~50 MH/s. Not only did it not work, but 2 or 3 no longer worked and I was stuck back on one GPU running at 12.4 MH/s. I spent hours tinkering until finally I was able to get two GPUs mining again. More tinkering and I was able to get three GPUs recognized and running, but only two GPUs mining.
Three GPUs detected during startup
Three GPUs beginning to run
You can see the fans spinning on all three GPUs
Yet the 3rd GPU would drop off (while still running) and 24.8 MH/s gets recorded
Another hour spent unplugging everything, plugging it all back in, switching wires around, and I got three to work: currently running at 37.1 MH/s. The fix ended up being switching the 2nd GPU with the 3rd GPU -- I have no clue why that fixes it, but welcome to the mining game.
I want to try to get 4 running, but given what I've went through to finally get three to work I'm not sure I want to deal with it. That said, my profitability with three running is likely about $0.008 per hour, so it's not like the downside is that bad. But my goal is to basically get .2 ETH mined -- to hit the minimum payout for my pool -- and to either quit, or mine different coins, so at least this way I would mine it somewhat faster. Will report back in a few days when I'm overcome by boredom and boldness and go for the 4 GPU glory again.
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Get it tweaked and maybe set it on a reliable LTC pool for a while? Might be a safe move.
I don't think it's the pool, seems like it's the motherboard/GPUs/power supply. Been messing around with getting 4 GPUs set up but keep failing and then it takes a lot of tinkering to get 3 back up and running.
I'll experiment with different coins too, will switch to ZEC sometime (mostly because I don't have a trustworthy XMR wallet)
Sounds like a lot of work for not a lot of reward, lol. Maybe easier-to-mine altcoins would give a better return rate?
It's more issues with the mining rig than the specific coin I'm mining.
According to whattomine, Ethereum is still the most profitable coin for GPU mining. I'm not sure how accurate this site is, but I'm sure it's a better heuristic than I'd come up with on my own.
I originally did this to learn more about computers and mining in general than to profit, but I did look at it as an interesting way to slowly turn fiat into crypto, and thought it would be slightly profitable. While I've learned some stuff, it's been more frustrating than anything, and I'm barely profiting at all, but at least it gives me something interesting to blog about sometimes.
I'll probably switch to different coins at some point, but I do have to mine .2 ETH before receiving a payout, and since I'm already about 6.5% of the way there (about $4 worth of ETH mined), I figured I'd at least stick it out til receiving a payout before tinkering with other coins.