Samsung PM991 (OEM) 512 GB vs Crucial MX300 256 GB
Short answer: which is best?
Samsung PM991 (OEM) 512 GB is 53.8 % stronger than Crucial MX300 256 GB. Samsung PM991 (OEM) 512 GB ranks #50 of 54 measured system drives at WhatFPS (4,385 Drive score over 1 verified runs). Crucial MX300 256 GB ranks #52 of 54 measured system drives at WhatFPS (2,851 Drive score over 1 verified runs). The numbers are measured in 2 verified WhatFPS runs — not estimated, not self-reported.
Measured comparison
| Metric | Samsung PM991 (OEM) 512 GB | Crucial MX300 256 GB |
|---|---|---|
| Drive score (the drive's own performance: sequential read + 4K IOPS) | 4,385 | 2,851 |
| Best rig (GAMING — whole PC) | 4,283 | 2,105 |
| Sequential read | 1,237 MB/s | 490 MB/s |
| 4K IOPS | 5,455 | 5,821 |
| 4K latency, median (lower is better) | 176 µs | 168 µs |
| Type | SATA SSD | SATA SSD |
| Size | 512 GB | 256 GB |
What the numbers mean
The drive score is the system drive's measured performance in the rigs it sat in — sequential read and 4K IOPS, unbuffered. PCIe generation, fill level and driver affect it. GAMING is the whole rig's score. We show both and never mix them.
All numbers come from our benchmark suite, the same test on every PC, written in Rust with no middleware. The methodology is open at https://whatfps.com/metodik
All measurements for Samsung PM991 (OEM) 512 GB · All measurements for Crucial MX300 256 GB