ReforgePC Blog

How to Check a Used Graphics Card Before You Buy: The 10-Minute Test

A used GPU can look perfect and still be weeks from dying. Here is the 10-minute test we run on every card, and what each result means for you as a buyer.

A used graphics card is the best value in PC gaming, and it's also where buyers lose the most money. Most bad cards don't look bad. They boot, show a desktop and often run a game for a few minutes. The problems show up when the card gets hot, and by then you've already paid.

This is the test we run on our bench before any card goes up for sale. You can do all of it in front of the seller in about ten minutes, with free software and a phone torch.

The rule: if the seller won't let you run a stress test, don't buy the card. A seller with a good card has nothing to hide.

What to bring

• A laptop or pen drive with GPU-Z, HWiNFO and a stress test such as FurMark or OCCT (all free)
• Your phone torch
• If you're testing on the seller's PC, ask them beforehand to have a monitor and a decent power supply ready

Minute 0–2: look before you plug in

Turn the card over and use the torch. You're looking for signs of a hard life or a repair that nobody told you about.

• Oily marks around the edges of the board or on the backplate. Old thermal pads leak oil when they've been cooked for a long time.
• Dust packed deep in the heatsink fins. Surface dust is normal. A solid wall of it means the card ran hot for a long time.
• Screw heads and warranty stickers. Chewed screws or a torn sticker mean the card has been opened. That isn't always bad, but ask why.
• Brown or dark patches on the board, especially near the power connectors. That's heat damage.
• The gold PCIe contacts along the bottom. They should be clean and even, with no deep scratches or burn marks.
• Fans. Spin each one by hand. They should turn freely and stay level, with no wobble or grinding.

Minute 2–4: check the card is what the seller says it is

Install the card, boot up and open GPU-Z.

• Check the GPU name, memory size and memory type against the official specs for that model. Old cards are sometimes flashed with a modified BIOS so Windows reports them as something newer. GPU-Z flags many of these fakes, and their shader count and release date won't match the real model.
• Note the BIOS version. A BIOS that doesn't belong to that brand and model means the card has been flashed, often after mining.
• Check that the bus interface runs at the speed the card and the motherboard support. A card stuck at a much lower link speed can have damaged contacts.

Minute 4–14: the stress test (this is the one that matters)

Start the stress test and keep HWiNFO open on its sensors page. Let it run for at least ten minutes. A card that has been "revived" usually behaves when it's cold and fails once it heats up.

While it runs, watch for these:

1. Artifacts. Coloured dots, flickering lines or checkerboard patterns on screen. Any of these means walk away.
2. Crashes or black screens. Same answer.
3. Core temperature vs hotspot. On cards that report a hotspot temperature, look at the gap between the two. A gap that keeps growing, or one much larger than reviews of the same model show, usually means dried paste or a cooler that isn't sitting properly on the chip.
4. Memory temperature. Many cards report a "memory junction" temperature in HWiNFO. Memory can be cooking while the core looks fine, especially on cards that were mined on.
5. Clock speed. If the core clock keeps dropping while the temperature sits at its maximum, the card is throttling, which means its cooling is struggling.
6. Fans. Listen for rattling or grinding once they're spinning at full speed.

Minute 14–15: one real game

Close the stress test and launch a game the seller has installed, at settings that load the card. Stress tests and games stress a card differently, and a minute of real gameplay sometimes shows stutter or crashes the stress test missed.

The paperwork

• Ask for the original invoice. Check the serial number on the card's sticker against the box and the invoice, then check it on the manufacturer's warranty page. Some brands honour the remaining warranty for a second owner and some don't, so read that brand's policy before you count on it.
• A "sealed box" means nothing. Shrink-wrap can be redone in minutes. Trust the serial number and the stress test.

What about ex-mining cards?

Mining isn't an automatic no. A card that mined at sensible temperatures in a clean, cool room can be in better shape than one that gamed in a dusty cabinet. What matters is how it tests: memory temperature, fan health, a clean stress test and a price that reflects its history. If you want the full answer, read why used GPUs die in 90 days.

The short version

Look closely, run GPU-Z, stress-test for ten minutes while you watch temperatures and clocks, then play one game. If the seller won't allow any of that, the answer is already no.

Every graphics card in our GPU section has been through this test on our bench, and its readings are published on the listing.