The potential to have reduced gaming performance from a used mining card has been a long-debated question. YouTube channel Testing Games posted a new video to look into the matter. Testing Games benchmarked a used RTX 2080 Ti that's been mining hard for 1.5 years, compared to a fresh new RTX 2080 Ti.
When graphics cards are subjected to long durations of mining time, this can cause accelerated wear and tear on the card's components and cooling system. All these changes can cause some deterioration to the card's performance in the long run.
In the video, Testing Games ran an assortment of gaming benchmarks, including Cyberpunk 2077, Battlefield V, and Forza Horizon 4. On average, the used mining 2080 Ti was about 10% slower than the brand new 2080 Ti. One outlier was Forza Horizon 4, which showed the mining card as 20% slower than the new card.
The main culprits for the reduced performance are GPU clock speed and temperatures. On average, the heavily used RTX 2080 Ti mining card was 16C hotter than the brand new RTX 2080 Ti. This caused over a 100MHz drop in boost frequency for the mining card, creating the performance losses. This is totally normal as Nvidia's GPU Boost 4.0 algorithm (equipped on Turing and Ampere-based cards) is tuned to be very sensitive to GPU temperature.
Unfortunately, Testing Games didn't benchmark the used mining card with replacement thermal pads and a fresh new application of thermal paste. Oh, and cleaning — dust buildup in the heatsink fins can also greatly hinder cooling performance. Theoretically, this should be all that it takes to bring GPU temperatures back down to normal and gain all that performance back.
Even if you aren't a miner, this test shows why it's a great idea to dust out your computer every now and then, and even apply a fresh coat of thermal paste to your CPU and GPU after several years. Thermal paste is known to get dry (especially on laptops) after years of use, which will reduce its thermal performance. Typically the hotter the CPU or GPU is, the faster the TIM will dry out. Besides, after three years, the warranty period on the card has likely expired so you've got nothing to lose.
This also applies to gamers buying used mining cards on eBay or from some other retailer. If you find the used graphics card underperforms, all it might need is a bit of maintenance to bring the card back up to full speed. Just be sure to factor in the costs (time and thermal pads) when bidding.