Development log of a life-long coder

How to benchmark disk drives on Windows

My computer (running Windows) has multiple drives in it and I was wondering which drive is actually the fastest. Fortunately, there's an app for that.


In the past, I kept up to date on computer hardware (because, let's be honest, games), but I've been lazy for the past decade or so.

I recently inherited some new parts and now I've got 3 drives:

  1. Cheapo solid state drive I bought off Newegg a few years back
  2. 1 TB rotational drive I salvaged from a discarded Western Digital My Book
  3. Fancy new non-volatile memory (NVMe) drive

My limited understanding tells me that the NVMe drive should be the fastest and that the rotational drive should be incredibly slow in comparison.

Benchmarking with DiskSpd

Enter DiskSpd, an official disk benchmarking tool from Microsoft. It's just an executable that you download and run (as administrator).

It has a lot of command line options, but a random article I found directed me to the most relevant ones.

In my case, I'm just interested in read performance, so I ran the following two commands (the first, -s, is for sequential reads and the second, -r, is for random reads):

diskspd -d10 -c128M -t1 -o1 -Sh -w0 -s d:\tmp.dat
diskspd -d10 -c128M -t1 -o1 -Sh -w0 -r d:\tmp.dat

These tests run:


Drive Sequential (MB/s) Random (MB/s)
SATA SSD 190 130
Rotational 55 8
NVMe 550 530

As expected, the NVMe drive was the fastest and the rotational drive was the slowest (especially for random reads)... but the actual gaps are enormous!

I guess if I ever get to a point where I have a project that is big enough that disks become the bottleneck, I can just throw everything over onto the NVMe and enjoy a ~3x speedup. Good to know!