AS SSD Benchmark Explained: What Each Metric Really Means

AS SSD Benchmark: Complete Guide to Interpreting Your SSD Scores

What AS SSD measures

• Sequential Read/Write (MB/s): performance for large contiguous files; reflects real-world large-file transfers.
• 4K Random Read/Write (IOPS): small-block performance for OS and application responsiveness.
• 4K-64Thrd Read/Write (IOPS): random performance under queue depth and multithreaded workloads (server/multi-tasking scenarios).
• Access Time (ms): latency for read and write operations; lower is better for snappier performance.
• Score: aggregated number combining the above metrics to give an overall performance indicator.

How to run AS SSD (concise steps)

1. Download and unzip AS SSD Benchmark.
2. Close background applications and disable disk-intensive tasks (virus scans, backups).
3. Select the target SSD in the tool.
4. Click “Start” and wait for the tests to complete.
5. Record results and, if desired, rerun 2–3 times and use the best consistent run.

Interpreting key results

• High sequential MB/s but low 4K IOPS: drive is good for large transfers but may feel sluggish for OS/apps.
• High 4K IOPS but low sequential: excellent system responsiveness; less ideal for bulk file copying.
• Large gap between 4K and 4K-64Thrd: drive struggles under multithreaded loads—may indicate controller or firmware limitations.
• High access times (>1 ms): noticeable lag; likely issues with drive mode (e.g., SATA AHCI vs IDE), drivers, or SSD health.
• Overall score: useful for quick comparison but don’t rely on it alone—compare individual metrics relevant to your workload.

Common causes of poor scores and fixes

• SATA mode or drivers: enable AHCI and install latest chipset/NVMe drivers.
• Full drive / low spare area: free up space or secure erase to restore performance.
• Firmware outdated: update SSD firmware per manufacturer instructions.
• Background tasks / thermal throttling: pause heavy tasks and ensure proper cooling.
• Incorrect benchmarking conditions: run tests with cold drive (reboot first) and avoid trim/influence from caching.

Quick workflow to diagnose low scores (3 steps)

1. Verify AHCI/NVMe drivers and firmware.
2. Check free space and run secure erase if appropriate.
3. Re-test in clean boot; if still poor, compare to manufacturer specs and consider RMA.

When to trust AS SSD vs other tools

• Use AS SSD when you want raw device-limited results without caching effects. For broader context, compare with CrystalDiskMark (different test patterns and optional mixed/random tests) and real-world file-copy tests.

Final tips

• Run multiple benchmarks and average or use best consistent run.
• Focus on metrics matching your use case (4K/IOPS for OS; sequential MB/s for transfers).
• Keep firmware and drivers updated and maintain adequate free space and cooling.