There's nothing wrong with pre-built PCs, but for mining, usually, we built rigs with motherboard with 5 or more slots of PCIe to maximize the profits and waste less energy with cpu, memory etc
Another thing is the PSUs, usually we buy strong PSUs, to let run with maximum of 80%, and it's good to be at least Gold, because you'll have more efficiency, remember, less watts is more profit
But, you can mine with your PC, and to maximize the 1080ti you already have, put 60% os power limit, set the maximum overclock0 on memory you can, until crash or have a lot of reject shares
Use a updated miner, because they have straps option and your card can achieve 50Mhs more or less
If your motherboard have another PCIe, you can buy another GPU and mine together, check the wattage of your PSU first
About your paragraph, I don't recommend motherboards with only 1 PCIe, this is the most limit factor to maximize the profits, remember we are in a bull market, almost every card can make profits even with expensive electricity, but in a few weeks or months the market and difficulty will probably be different, and it's better to be efficient to stay on business.
Yes that was why I asked, so its more efficient to just go with a single rig than multiple single PCIE pcs? Is 700 watts bad (it would be plugged in the same room as my 800 watt everyday pc)
My 1080ti has never truly preformed as it should, even in gaming. Its always close, but never what it needs to be. It seems a little bit better now that im using "minerstat". the only thing im having issues with is the pool is generating far less than it estimates in miner stat.
What were profits like before? I think I walked into this at the peak, and every day the prices have fallen.
edit: Would it be possible to use an amd and nvidia gpu in the same rig? i guess i do have an extra slot in my current. Its just crossfire, and its only the one. The only reason i dont buy sli motherboards is because ibuypower does not sell more than 1 gpu. I want to get a true mining rig, I just cant afford much right now. I might skip over the prebuilt idea. Honestly, untill I can figure out how to get the actual money im mining, and not what seems to be half what the program promises.
Copy and pasted from my ether mine dashboard.
Workers Active / Inactive
1/0
Unpaid Balance
0.72
Estimated Earnings
1.82
Hashrate
Current
12.2 MH/s (Not true its 45)
Average
480.5 kH/s (not true its 45)
Reported
45.0 MH/s
Shares
Valid 100%
11
Stale
0
Number of stale shares submitted during the last hour.
Invalid
0