Head-to-head · PC Stress Testing Tools
HeavyLoad vs Prime95
HeavyLoad leads on 0 checks, Prime95 on 0, and 5 are even. Who comes out ahead on the 5 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.
Our verdict
- Highest scoreHeavyLoad · 8.4/10
- Free planboth
- Most featuresHeavyLoad · 4 of 5
HeavyLoad scores higher on our rubric for pc stress testing tools: 8.4 against 8.0 out of 10; our editors rank them #4 and #7.
HeavyLoad is the better fit for free Windows tests across CPU, GPU, RAM, and disks. Prime95 is the better fit for established CPU and cache stability testing.
- HeavyLoad fits best
Free Windows tests across CPU, GPU, RAM, and disks
- Prime95 fits best
Established CPU and cache stability testing
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Side by side
| Feature | HeavyLoad 8.4/10 Visit ↗ | Prime95 8.0/10 Visit ↗ |
|---|---|---|
| At a glance | ||
| Editor score | 8.4 | 8.0 |
| Ranking | #4 in PC Stress Testing Tools | #7 in PC Stress Testing Tools |
| Best for | Free Windows tests across CPU, GPU, RAM, and disks | Established CPU and cache stability testing |
| Pricing model | Free | Free |
| Starting price | Free plan | Free plan |
| Free plan | ✓ | ✓ |
| Free trial | — | — |
| Deployment | Desktop | Desktop |
| Platforms | Windows | Windows, macOS, Linux |
| Support | Docs | Community, Docs |
| Built for | Solo, Small business, Mid-market, Enterprise | Solo, Small business, Mid-market |
| Features HeavyLoad 4/5 · Prime95 0/5 | ||
| CPU stress testing | ✓ (best) | Not checked yet |
| GPU stress testing | ✓ (best) | Not checked yet |
| Memory stress testing | ✓ (best) | Not checked yet |
| Combined system workload | ✓ (best) | Not checked yet |
| Error detection | Not checked yet | Not checked yet |
| Specs | ||
| Platform support | Windows | Not checked yet |
| Our review | ||
| Pros |
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| Cons |
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| Our verdict | HeavyLoad is a free Windows utility from JAM Software GmbH for checking how PCs and server systems behave under resource-intensive conditions. It suits people who need to apply load to individual components or combine several workloads to… Read the review → |
Prime95 is free desktop software for computer stability testing and participation in distributed Mersenne-prime searches. It suits people who want to put sustained load on a CPU, check cache stability, or run primality and factoring… Read the review → |
Strengths and trade-offs
HeavyLoad — where it wins
- Tests CPU, GPU, memory, and disk activity individually or together
- Runs continuously or for a specified duration, with command-line controls
- Offers an installer and portable version for USB use
Where it doesn't
- Windows-only, with no support for other listed platforms
- Provides stress workloads, not the deeper reporting and error detection some buyers need
- Documentation is the only listed support channel
Prime95 — where it wins
- Runs high-load torture tests across multiple CPU cores
- Tests CPU and L1, L2, and L3 cache stability
- Free on Windows, macOS, and Linux
Where it doesn't
- Does not cover GPU or storage stress testing
- Focuses on CPU and cache workloads rather than broad component testing
- Support is through community resources and documentation
- HeavyLoad8.4/10 · Free plan
A free Windows utility for combined or targeted PC stress tests.
Visit JAM SoftwareFull verdict → - Prime958.0/10 · Free plan
A focused, free option for CPU and cache stability testing across Windows, macOS, and Linux.
Visit Prime95Full verdict →
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Last updated · How we research and update