Raspberry Pi USB Boot - UASP, TRIM, and performance

In the past few weeks, I reviewed USB drive performance on the Raspberry Pi 4, and the importance of UASP support for USB drive performance.

Both posts generated great discussion, and there were three things I wanted to cover in this follow-up, namely:

  1. Which drives support UASP
  2. Real-world performance benchmarks
  3. TRIM support

For reference, here are all the products I'm testing in this post (product links are to their Amazon product page, starting from top middle, clockwise):

USB Performance testing - SATA SSD, NVMe, and Flash drives

Enabling TRIM on an external SSD on a Raspberry Pi

I've been doing a lot of benchmarking and testing with the Raspberry Pi 4 and SSDs connected via USB. I explored UASP Support, which USB SSDs are the fastest, and I'm now booting my Pis from USB SSDs.

Anyways, one thing that I have wondered about—and some people have asked me about—is TRIM support.

I'm working on a new video for my YouTube channel that will go into some more detail on which of the drives I tested support TRIM, but while I was researching for that video, I also found that TRIM support in Linux is not as simple as it seems at first glance—it's definitely not plug-and-play, in my experience.

While internal microSD cards seem to support TRIM out of the box, none of the external USB drives I tested supported it out of the box. They all needed a little help!

UASP makes Raspberry Pi 4 disk IO 50% faster

You can view a video related to this blog post here: Does UASP make the Raspberry Pi faster?.

A couple weeks ago, I did some testing with my Raspberry Pi 4 and external USB SSD drives. I found a USB 3.0 SSD was ten times faster than the fastest microSD card I tested.

In the comments on the video associated with that post, Brad Manske mentioned something I never even thought about. He noticed that I had linked to an Inateck USB 3.0 SATA case that didn't have UASP.

What's UASP, you might ask?