Understanding CrystalDiskMark Results
After you run a benchmark, you see numbers in the grid (e.g. SEQ 1M Q8T1, RND 4K Q32T1). This page explains what those labels mean and what typical results look like for different drive types.
Sections are ordered as: units used, test types, what to expect by drive, and profiles. Use the table as a rough reference when comparing your SSD or HDD to others.
Units Used
- MB/s (GB/s): 1 MB/s = 1,000,000 bytes/sec in CrystalDiskMark (decimal).
- IOPS: Input/output operations per second — important for random workload.
- μs (latency): Average response time in microseconds; lower is better.
1 GB = 1000 MB = 1000×1000 KB (decimal). 1 GiB = 1024 MiB (binary).
Test 種類s
SEQ（シーケンシャル）
Reads or writes large blocks in order. Reflects throughput for big files (videos, installers, backups). Block size 1 MiB (default) or 128 KiB for NVMe profile.
RND (Random)
4 KiB random read/write. Simulates OS and apps (many small I/Os). Q32T1 = queue 32, 1 thread; Q32T16 = 32 queue, 16 threads (stresses NVMe).
Rough Expectations (varies by drive)
| ドライブタイプ | SEQ read (typical) | RND 4K (typical) |
|---|---|---|
| NVMe Gen4 SSD | 5000–7000+ MB/s | High IOPS, low μs |
| NVMe Gen3 SSD | 2000–3500 MB/s | High IOPS |
| SATA SSD | 500–560 MB/s | Tens of thousands IOPS |
| HDD 7200 rpm | 150–200 MB/s | Low IOPS, high μs |
| USB 3.0 flash | 50–400 MB/s | Varies widely |
Results depend on test size, file position, fragmentation, controller, and CPU. Don't compare across different major versions of CrystalDiskMark.
Profiles: Peak vs リアルワールド vs Demo
- ピークパフォーマンス: Pushes the drive for maximum numbers; may not reflect daily use.
- リアルワールド Performance: Settings tuned to reflect more typical usage patterns.
- Demo: Short run for quick demos; not for strict comparison.
Next steps
To run a test: 使い方. For common questions: よくある質問. For real-user tips: ユーザーの声.