I built my PC near the end of 2024, originally using a Radeon 6750 XT. After upgrading to an RTX 5070 and later an RTX 5080, American Truck Simulator performance improved from roughly 80 FPS with mods to over 150 FPS with mods and graphics add-ons. Recently, though, performance has collapsed to around 30 FPS with severe stuttering and occasional crashes. Other games have also become nearly unplayable unless I use low settings.
I have reinstalled Windows and the graphics drivers after each major hardware upgrade, and my drivers are currently up to date. During gameplay, GPU usage is usually around 80–90%, CPU usage is 50–70%, and neither component exceeds about 72°C. I do not see any obvious RAM or VRAM-heavy background process, and most of my files are stored on an external drive.
What should I check before resorting to another clean Windows installation? Could mods, malware, a driver issue, power settings, or hardware connections cause this kind of sudden performance loss?
5 Answers
Normal temperatures do not rule out a hardware or power problem. While gaming, watch the GPU core clock and board power rather than just utilization. If the card is stuck at a low clock, repeatedly hitting a power limit, or showing PCIe errors, reseat the card and its power cables and inspect the motherboard slot. Checking crashes in Reliability Monitor can help identify whether the driver, the game, or the hardware is failing.
Mods are worth investigating, especially since the issue appears strongest in a heavily modded game. Temporarily remove or disable every mod and test an unmodified game. A broken mod or corrupted configuration can cause crashes and severe stuttering, even if temperatures look normal. You can also verify the game files and clear its shader cache. If the clean game is still slow, test another demanding title to separate a game-specific problem from a system-wide one.
A clean Windows install probably is not the first thing to try. A system normally does not lose that much performance simply from being installed for a year or two. Monitor GPU usage, clock speed, power draw, CPU usage, RAM and VRAM while the game is running. Also check whether a frame limiter, V-Sync, resolution scale, or graphics preset changed unexpectedly. Reliability Monitor and Event Viewer may show errors that line up with the crashes.
The overlay shows the same general usage and temperatures I had before, but the frame rate is dramatically lower. I have not found another process consuming a significant amount of RAM or VRAM, so I am trying to avoid reinstalling Windows unless the other checks fail.
Check the NVIDIA driver installation and power settings before wiping the system. A bad driver update or corrupted shader cache can cause stuttering, so try a clean driver removal and install a known-stable driver version rather than automatically using the newest one. Also verify that Windows and the NVIDIA control panel are set to use the high-performance GPU, and confirm that the 5080's power connectors are fully seated. Updating the motherboard BIOS and chipset drivers is worth checking too.
Before reinstalling Windows, make sure the basics have not changed: monitor refresh rate, resolution, render scale, V-Sync, frame caps, Windows Game Mode, and the per-game NVIDIA settings. A cap or an accidental resolution setting usually will not explain every crash, but it can make one game look much worse. If several games are affected after driver cleanup, a fresh install becomes more reasonable, especially since your important files are already backed up.
I had considered malware in a mod but had not tested everything with the game completely unmodified. I will run a full Windows Defender scan and compare the stock game against the modded setup before doing a full reinstall.