I'm an old time flight sim fan who hasn't gamed in a while. When I used to upgraded my old hardware for the next and greatest version of Microsoft Flight Simulator, I would hold onto the old hardware. Fast forward 10 years and that old hardware is now mining Ethereum.
Strangely enough I wasn't planning on mining at all, I just wanted to get back into gaming, so I went out and bought what I needed, put it together and was chuffed with the results. I could play all the games I had bought on Steam over the years as they went on sale. Then I stumbled across a YouTube video explaining how to mine with an AMD graphics card. However, I didn't have one. Instead I had decided to go for a GTX 1060, but I thought whatever, let me have a go and see what happens. I ended up getting an average hash rate of 18MH/s which apparently isn't too shabby, so I bought another GTX 1060 and installed it in my games machine which doubled my hash rate.
That was as far as I could go with the games machine as it only has 2 PCI-E slots but then I thought "I wonder if some of this old hardware would be able to mine"? That lead to a lot of work configuring and testing and buying the odd part here and there to get everything up and running. To make a long story short, the old hardware works perfectly for mining and I now have 4 additional machines, besides my gaming machine, mining away quite happily. In case you are interested, here are some of the specs:
New gaming machine:
ASUS B250M-PLUS with Intel i5-7400
24GB DDR4-2400 (I was going to play X-Plane so needed loads or RAM, oops)
2 x GTX 1060
Old machine 1:
Intel D975XBX2 with Core 2 Quad Q6700
8BG DDR2-800 (as much as this motherboard can take)
1 x GTX 1060 (tried more than one but I think the motherboard runs out of PCI-E lanes and can't enable the 2nd card even though it has 3 PCI-E slots)
Old machine 2:
Intel D946GZIS with Core 2 Duo E7300 (had a D925 which uses way too much power)
4GB DDR2
1 x GTX 1060 (only has one PCI-E slot)
Old machine 3:
Gigabyte 945GCM-S2L with Core 2 Duo E7500
4GB DDR2 (but because of the chipset only sees 3.75GB)
1 x GTX1060 (also only has one PCI-E slot)
Old machine 4:
Intel D975XBX with Core 2 Quad Q6600
8BG DDR2-800
1 x GTX 1050 (because I had bought the 1050 thinking my old motherboards surely wouldn't work with a 1060)
So the moral of the story, at least for me, is never throw out old computer parts, because you just never know when you can put them to good use.