How to test ex-mining GPUs before selling them
A card that mined for two years at a steady undervolt can be in better shape than one that was gamed hard — but mining leaves settings behind that make a healthy card look faulty. Undo those first, then run the checks that matter most for mined cards.
1. Put every card back to stock
- Clocks and undervolts. Reset any overclock, memory offset, power limit or undervolt in MSI Afterburner or the driver’s tuning page, and remove any tool that applies them at startup.
- Modified BIOS. Many AMD cards were flashed with a mining BIOS with tightened memory timings. Flash back the original BIOS you saved, or the stock BIOS for that exact board. A modded BIOS can cause crashes in games that look like a hardware fault.
- Drivers. Test in Windows with the standard gaming driver, not a mining OS.
2. Clean and look them over
Blow the dust out of the heatsink with compressed air, holding the fans still. Then check each card for corrosion on the board or connectors — common in damp farms — bent brackets, and wear on the gold edge connector from years in risers.
3. Check the fans
Mining ran fans at a constant speed for months, so fan bearings are the part most likely to be worn. Under load, every fan should spin smoothly without grinding, rattling or a wobble. A worn fan is a known, cheap fix, but say so when you sell.
4. Memory temperatures and VRAM
Cards with GDDR6X memory — the RTX 3080, 3080 Ti, 3090 and 3070 Ti among them — report a memory junction temperature, which HWiNFO shows. Readings pushing past 100 °C under load usually mean the thermal pads have worn. Then test the memory itself with OCCT’s VRAM test or the free memtest_vulkan; any reported error is a faulty memory chip.
5. A load test in a normal PC
Test each card on its own in a normal desktop, in the PCIe slot rather than a riser, with a monitor on each output in turn. Run a 3DMark stress test or a demanding game for 15 to 30 minutes and watch for artifacts, driver resets or black screens. Our full GPU testing guide goes through each check.
Testing a whole rig’s worth
With six or more cards, label each one as you test it and write down what you found. Cards that pass sell as working; a card that fails gets no offer from us, but can go in the same box to be recycled. List the working cards and their counts on the mining rig page for an instant offer, then pack them for shipping.