One housekeeping note first. MakeUseOf's original roundup numbers five tools: Unigine, 3DMark, OCCT, FurMark and MSI Kombustor. It mentions GravityMark from Tellusim only as a free alternative inside the Unigine entry. The sixth tool below is therefore GravityMark, so the full set is all six.
What a stress test can and can't tell you
A stress test applies sustained graphics load so that instability shows up on your terms, not mid-game. 3DMark's own guidance describes the symptoms to watch for. Crashes, hangs or visual artifacts during a run can point to a reliability or stability problem, and an overheat-and-shutdown suggests you need better cooling.
There is a catch. Passing a synthetic test doesn't certify your card for every game. Workload, power draw, memory use and graphics API all differ from one program to the next. Treat a pass as "this configuration survived this test under these conditions," nothing more.
The FurMark problem: very heavy, deliberately
FurMark deserves a special warning. NVIDIA's guidance describes it as an application designed to stress the GPU by maximizing power draw well beyond any real world application or game. In some cases this can slow the card down when it hits over-temperature or over-current protection. The same guidance adds that using such tools to disable those protections can cause permanent damage and void the warranty.
That is a warning about disabling protections, not a claim that ordinary FurMark runs wreck modern cards. Community discussion on Overclock.net makes a related point. Modern GPUs are power-limited, so FurMark is unlikely to harm a healthy card with its limits intact. The same thread notes that heavy throttling says little about stability at more typical clocks. That is a forum opinion, not vendor documentation. It fits the practical advice, though. Use FurMark to see worst-case heat and power, and use a more game-like test to judge overclock stability.
The six tools
1. Unigine Superposition
Superposition is a visual benchmark with a looped stress mode. Unigine's page lists GPU temperature and clock monitoring among its features and offers a free download for Windows and Linux. The Basic edition is free. Features such as the looped stress test and custom settings sit in paid editions, with Advanced listed at $19.95 for personal use. Commercial use needs a higher tier.
MakeUseOf says custom presets run from 720p to 8K and that the benchmark has 17 scenes. Unigine's page lists version 1.1 from 2019, so this is a mature tool, not a fresh one. Check the options in the build you download before relying on specifics.
2. 3DMark
3DMark is a benchmark suite first and a stress-test tool second. UL's page describes Steel Nomad as the successor to Time Spy, running at 4K with new techniques like volumetric skies and procedural grass. UL also offers a lighter Steel Nomad Light for portable systems. Per MakeUseOf, the free Demo includes Steel Nomad, Steel Nomad Light, Time Spy, Fire Strike and Night Raid. Stress Test mode, custom settings and the ray tracing and feature tests require the paid edition, which MakeUseOf lists from $34.99.
Keep the distinction clear. A benchmark score tells you how fast the card is. A stress-test loop tells you whether it stays stable. They aren't interchangeable. UL also says that all currently supported 3DMark benchmarks and feature tests are compatible with Windows 11.
3. OCCT
OCCT is the error-hunting specialist. It's a good fit for overclocked or undervolted setups. MakeUseOf says the GPU test lets you set a duration and a video memory usage range. It also offers a critical-temperature limit and a stop-on-error option. Confirm the exact labels in your build before following them step by step.
On licensing, OCBASE's download page says OCCT Personal delivers all the core features of OCCT, free of charge, but it can't be used in a commercial or business environment. Pro, Enterprise or Enterprise+ licenses are required there. Paid Supporter access, via Patreon or Steam, adds unlimited test duration, no wait time between tests, and access to test reports and stability certificates. The page listed v17.1.10, dated 2026-10-21, as the current stable release when checked.
4. FurMark
FurMark is the classic worst-case load. MakeUseOf says FurMark 2 supports OpenGL and Vulkan on Windows and Linux and bundles GPU-Z and GPU Shark. XDA Developers notes it displays a warning dialog that it is very GPU intensive and can lead to crashes or instabilities. The dialog is real, so take it seriously.
Use it for thermals and power, run it supervised, and stop if anything looks wrong. XDA suggests running it for at least 10 minutes while watching temperature and usage. Other guides suggest 15 to 30 minutes. Those are one writer's suggestions, not rules. A shorter run may be wiser if your cooling is marginal.
5. MSI Kombustor
Kombustor is built on the FurMark engine. MakeUseOf says it supports OpenGL and Vulkan, includes an artifact scanner for rendering errors, and offers presets from 1080p to 2160p. It also includes dedicated VRAM tests and a PhysX-based test. The reviewer groups it with FurMark as a tool for enthusiasts who want to push hardware to its limits. I couldn't confirm these feature details against an MSI product page, so they rest on MakeUseOf's description. Expect FurMark-like power draw and heat.
6. GravityMark
GravityMark comes from Tellusim, and MakeUseOf describes it as a free option. Tellusim's site calls it a GPU stress/stability/efficiency test and API performance verification tool, with command-line presets for automation. It lists Vulkan, Direct3D, OpenGL and Metal support. Windows installers include v1.89, with an ARM64 build. Tellusim says you can raise GPU load by increasing the number of rendered objects.
I couldn't confirm the "free" claim from Tellusim's page, so check the license terms before using it. Compare results only between runs with identical API and settings.
Quick comparison
| Tool | Best for | Main caveat |
|---|---|---|
| Unigine Superposition | Visual benchmark plus looped stability test | Stress mode is in paid editions |
| 3DMark | Scored benchmarks and comparison | Stress Test mode needs the paid edition |
| OCCT | Error detection on tuned systems | Free tier limits duration; business use needs a license |
| FurMark | Worst-case heat and power | Far heavier than games; throttling is common |
| MSI Kombustor | Artifact scanning, VRAM tests | Same heavy-load caveat as FurMark |
| GravityMark | Configurable, API-flexible load | Check licensing; compare only matching settings |
A safer testing routine
- Start from stock. Run a baseline at factory settings before you tune anything. A card that fails at stock has a different problem than an unstable overclock.
- Change one variable at a time. Adjust the core offset, memory offset, power limit or voltage curve separately, then retest.
- Monitor while it runs. MakeUseOf says NVIDIA's app overlay opens with Alt+R. Radeon users can use Adrenalin's overlay, which MakeUseOf says also includes a stress test under Performance Tuning. MSI Afterburner is a third-party alternative. Vendors change these interfaces, so confirm in your driver software.
- Watch more than temperature. Also track clock speed, power draw and fan behavior.
- Stay at the PC. Don't leave a heavy load running unattended.
- Stop on trouble. Visual artifacts, driver resets, crashes, odd fan behavior or temperatures beyond the maker's guidance all mean stop.
- Back off the tuning. If a test fails after an overclock, reduce the offset or raise cooling, then retest.
About temperature numbers
MakeUseOf suggests 65–85°C as a typical gaming range and calls sustained temperatures above 90°C a sign of overheating. Treat those as rough guides, not universal limits. Some GPUs are rated higher, and laptops differ from desktops. Check your GPU or laptop maker's specifications. A sudden drop in clock speed at a given temperature is itself a useful sign that the card is throttling.
Which should you pick?
- Checking a new build: a 3DMark or Superposition run shows whether performance is where it should be, and a looped test, where available, checks stability.
- Validating an overclock or undervolt: OCCT's error detection is the best fit.
- Testing cooling and power delivery: FurMark or Kombustor, carefully and briefly.
- Scripted or API-specific testing: GravityMark's command-line options suit it.
There's no single best tool. A sensible approach is to combine a game-like benchmark for stability with one heavy load for thermals. Then confirm with the games you actually play.