Explenation: If a seller sells the GPU's for lower price and in high quantities, then they probably come from a mining rig. Mining rigs that are used for mining crypto currencies. In my opinion, that isn't very fatal because most of the time they have been maintained, but their life span could've been shortened because of pushing higher core clock frequencies. Also, they can be running on a mining BIOS, or in simple terms, optimised for mining only, where you have to flash an old BIOS to be able to use it as a normal GPU. That isn't a problem for some people that know how to fix it.Thanks for the heads up Joseph,
I read a little about mining and crypto currencies but, I have to say I have no idea how that relates to computers and how they would tune one specifically for that purpose.
If you have the time please explain in moronic terms for me !
Thanks for your help,
Selecting GPU: The heads up I can give you is to look for people that sell only 1 GPU. It probably has been for gaming only and hasn't done any mining and hasn't had it's BIOS tampered with. That's your safest bet with a second hand GPU.
Testing GPU: If you can, test it, see if there are any artifacts under load, any strange noise, strange screen issues. You can do that by running FurMark and Unigine Heaven Benchmark at the same time at high settings.
Hope these helped.