Samsung PM9B1 (OEM) 512 GB vs Samsung PM981a (OEM) 1 TB
Short answer: which is best?
Samsung PM9B1 (OEM) 512 GB is 14.9 % stronger than Samsung PM981a (OEM) 1 TB. Samsung PM9B1 (OEM) 512 GB ranks #29 of 54 measured system drives at WhatFPS (8,373 Drive score over 3 verified runs). Samsung PM981a (OEM) 1 TB ranks #38 of 54 measured system drives at WhatFPS (7,285 Drive score over 1 verified runs). The numbers are measured in 4 verified WhatFPS runs — not estimated, not self-reported.
Measured comparison
| Metric | Samsung PM9B1 (OEM) 512 GB | Samsung PM981a (OEM) 1 TB |
|---|---|---|
| Drive score (the drive's own performance: sequential read + 4K IOPS) | 8,373 | 7,285 |
| Best rig (GAMING — whole PC) | 3,718 | 4,752 |
| Sequential read | 1,895 MB/s | 2,113 MB/s |
| 4K IOPS | 10,418 | 8,815 |
| 4K latency, median (lower is better) | 89 µs | 108 µs |
| Type | NVMe SSD | NVMe SSD |
| Size | 512 GB | 1 TB |
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 PM9B1 (OEM) 512 GB · All measurements for Samsung PM981a (OEM) 1 TB