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Compare storage performance

Choose two Models, then select Compare. You can compare different storage capacities.

Model A

NVMe SAMSUNG MZVLB256 SCSI Disk Device

238 GB · Windows

Sample count: 1

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Model B

PM991a NVMe Samsung 512GB

476 GB · Windows

Sample count: 3

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Your comparison

Storage performance

Swap A & B

Sequential read

MiB/s · higher is faster
A NVMe SAMSUNG MZVLB256 SCSI Disk Device · 238 GB2,226.09
B PM991a NVMe Samsung 512GB · 476 GB2,220.48

B is 0.25% lower than A

Sequential write

MiB/s · higher is faster
A NVMe SAMSUNG MZVLB256 SCSI Disk Device · 238 GB1,398.91
B PM991a NVMe Samsung 512GB · 476 GB474.82

B is 66.06% lower than A

4 KiB random read

MiB/s · higher is faster
A NVMe SAMSUNG MZVLB256 SCSI Disk Device · 238 GB39.16
B PM991a NVMe Samsung 512GB · 476 GB28.80

B is 26.44% lower than A

4 KiB random write

MiB/s · higher is faster
A NVMe SAMSUNG MZVLB256 SCSI Disk Device · 238 GB59.48
B PM991a NVMe Samsung 512GB · 476 GB61.93

B is 4.12% higher than A

Configuration details

DetailA · NVMe SAMSUNG MZVLB256 SCSI Disk Device · 238 GBB · PM991a NVMe Samsung 512GB · 476 GB
PlatformWindowsWindows
Sample count13
Latest measurement2026-04-112023-08-29
Random read IOPS10,0247,374
Random write IOPS15,22715,854
All capacitiesView Model →View Model →

Results checked · Speeds in MiB/s · About these measurements

Four tests. A clearer comparison.

Compare sequential and 4 KiB random read/write speeds side by side. Every option includes its Model, capacity and platform. You can compare 512 GB with 256 GB, including two capacities of the same Model.

How the tests work · Browse all results