SSSTC (Kioxia) CL4 (OEM) 512 GB vs ADATA XPG SPECTRIX S40G 256 GB
Short answer: which is best?
SSSTC (Kioxia) CL4 (OEM) 512 GB is 169.4 % stronger than ADATA XPG SPECTRIX S40G 256 GB. SSSTC (Kioxia) CL4 (OEM) 512 GB ranks #35 of 54 measured system drives at WhatFPS (7,571 Drive score over 1 verified runs). ADATA XPG SPECTRIX S40G 256 GB ranks #53 of 54 measured system drives at WhatFPS (2,810 Drive score over 1 verified runs). The numbers are measured in 2 verified WhatFPS runs — not estimated, not self-reported.
Measured comparison
| Metric | SSSTC (Kioxia) CL4 (OEM) 512 GB | ADATA XPG SPECTRIX S40G 256 GB |
|---|---|---|
| Drive score (the drive's own performance: sequential read + 4K IOPS) | 7,571 | 2,810 |
| Best rig (GAMING — whole PC) | 880 | 4,358 |
| Sequential read | 2,462 MB/s | 206 MB/s |
| 4K IOPS | 8,171 | 13,451 |
| 4K latency, median (lower is better) | 98 µs | 71 µs |
| Type | NVMe SSD | Unknown type |
| 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 SSSTC (Kioxia) CL4 (OEM) 512 GB · All measurements for ADATA XPG SPECTRIX S40G 256 GB