Tips & Tricks for Shopping Used PC Parts

by turbolence1988MAR 24TH, 2019

Are "Mined" Graphics Cards Safe to Buy?

The most common question we field in the OzTalksHW community is whether someone should buy a previously “mined” graphics card.

For those unaware, the cyrptocurrency boom a couple years ago was spurred by a slew of programs that let consumer graphics cards process blockchain hashes many times faster than CPUs. The reward for a successful hash on the Bitcoin blockchain is 12.5 bitcoins (hence where the “mining” term started), which was worth nearly $250,000 at one point in December 2017. This led to an unprecedented demand for these graphics cards from prospective “miners” and sent prices catapulting to double or even triple their MSRP. Both AMD and Nvidia ramped up production to pump out as many as they could, and it was only within the last year that prices came back down to earth as miners start to unload their unprofitable cards.

It’s a good assumption that any “mined” graphics card will have been run for long hours, if not 24/7, since miners would most often work on contract for a larger outfit that would divide the workload among thousands of contractor-provided GPUs for a steady payday. The issue is that not everyone treated their GPUs the same - while a professional mining operation could have undervolted, underclocked, and properly cooled their GPUs like delicate IT equipment, a hobbyist looking for a quick buck might have overclocked their cards to the stratosphere and let them run at or above their thermal limits.

So should we skip the mined ones altogether? When asked whether “heavily used” GPUs are risky purchases, Phil from PhilsComputerLab says he has never had an issue with used graphics cards purchased from similar high-usage environments, and suggests making sure that any such GPUs are properly tested and are sold at an appropriate discount due to their unusually high past workload.

Bryan from Tech YES City mirrored Phil’s sentiments, saying in his experience that used mined GPUs have a high success rate. Though he adds:

The thing to look out for on a mining GPU is is corrosion and whether that person had them in a properly cooled environment. If the corrosion is too heavy on the cards then treat with caution.

While corrosion is usually not a major concern for used graphics cards, his reasoning in the case of mined cards is valid. Mining farms will generate a lot of heat, and if the environment is not properly cooled there will be much higher ambient humidity, accelerating corrosion. Seller pictures may show this but it’ll always be easier to tell if corrosion has set in once the card is in your hands. Check the screws and take the cooler shroud off to look for any signs of early corrosion - it may not be in obvious places.

We also want to briefly mention that any seller offering up mining cards should be able to answer whether the card’s BIOS was flashed back to stock. Professional miners often flashed custom BIOS files that unlocked voltage controls far beyond what Afterburner or AMD WattMan would allow, which could cause errors when attempted to be used with common graphics drivers. It’s possible to re-flash the BIOS yourself using GPU-Z, but this carries the risk of bricking your card if you don’t use the correct file or an unexpected error occurs.

All things considered, mined GPUs are generally going to be no more or less risky on the whole than any other used part. A little extra due diligence is warranted, but as with buying anything secondhand, it’ll come down to the seller and their willingness to be open and honest with prospective buyers.