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.

Background

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:

• For 10 seconds
• On a 128 MB test file (which DiskSpd leaves behind after it finishes)
• On a single thread
• With one operation outstanding
• Without write caching (probably unnecessary for read tests)
• 0% of operations are writes
• In sequential or random access, as indicated
• On a file named d:\tmp.dat (I change the drive letter for each drive, obviously)

Results

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!