I have never been able to write more than about 3 MB/second to any USB 3.0 flash drive with a USB 3.0 host computer. USB 2 sometimes reached about 5 MB/second. Not quite usually that "fast" though. 2 MB/second would be a real speed machine. I am currently writing at 18 KB/second which for me is pretty standard with USB flash drives. I will only need another 14 hours to copy a 1 GB file.

If I could time travel back to 1996 I could get a nice USB 1.1 drive which would blow this one out of the water. Or maybe an Iomega ZIP or Jazz drive with parallel port interface would destroy this drive.

Do you think USB 4 will go back to stone tablet writing speed? Are there any USB flash drives with a GUARANTEED write speed or your money back?

My USB3a speeds are far higher than USB2 speeds. You have something wrong. Have you tried a different USB3 port on the same machine?

A lot of USB3 pendrives do have slow write speeds, around 10, whilst read speeds are 100+.

I've always found this an odd situation.

I too find that writing to USB2 pendrives is faster, so tend not to use my 32GB USB3 much at all.

It's totally different when using an external USB3 HDD/SSD though, the write speed is massive compared to USB2.

Sorry you guys know I go off on a rant sometimes. The copy did eventually complete. The way flash drives copy is really bursty and annoying going from stalled back to a few MB per second. I wanted to add that I had to move my Pi 4 staging server over to a high speed Micro SD card because Samba transfers were moving at a monumental speed of perhaps 13 MB second at best with a USB 3 flash drive - on a gigabit network. The high quality micro SD card does 34 MB/second at worst. I think one factor in this may be the brand. I would stay away from PNY because that is where a lot of my problems are coming from. Anyway I do not trust any flash drives. Even an old hard drive in a USB 2 enclosure can get about as much as 60 MB/sec from what I remember.

Consider buying more expensive thumb drives.

Those little usb sticks vary a lot. I have some cheep ones, and get around 7-8 MBps on both usb2 and usb3 ports. (According to gkrellm) That's just all the faster they write to.

Depends on what file system that you have on them. Also depends on how you mount them. Talked about that in other threads. Not necessarily how fast they write, but how even they write.

You have something really wrong. What file system is on it, what are you using to write to it, how big is the cache size in RAM while you are writing to it, what are your mount flags, how large is the dirty bits size, dirty background bytes size, all of that effects write speed/even write speed. Just one stick or all of them?

Different kernels even affect the usb stick write speed. Could be just a junky stick too, why I asked if just one or all sticks.

Something is wrong when the write speed to them fluctuates all over. Something weird about the way bits are being cached and then dumped to the stick.

Do you get the same thing if you make a little RAM disk, a little larger than your files, then write from RAM to the stick?

Example:
That eliminates any other bottleneck.

Also look at the async and flush options for mount.

Answer to question: Not usually .

Only thing I use a 'thumb' drive for is as a new Live OS boot drive, or for Clonezilla. Seem fast enough write/read for that purpose. Yes, they are 'bursty'. Seems to stall while writing files (probably no cache as cheap as they are).

However for everything else, I've simply moved on to external SSDs. Small (almost as small as thumb drive anymore), plenty of storage, reliable, and fast. Something like the Samsung T5 or T7. But yes, the trade off is quite a bit more expensive if moving a limited number of small files. On the other hand, big files, small files, the SSD doesn't seem to care...

BTW, speaking of RPI4s, a 500GB T5/T7 makes for a dandy reliable BOOT/Storage drive for the RPI-4. Eliminate the SD card completely.

It appears the 'thumb drive' is on the way out (from my point of view). I used to buy a lot of them and used them in the past. Not any more. I can't use them to bring work home or back to work (good security reasons). Internally at work, in 'very' special circumstances can we use a usb drive. And at home I have my external SSDs for whatever use I want to put them.

I tend to buy the highest quality and fastest models.

The conclusion is that while some may be faster than a few megabyte per second they ALL are in fact terrible. No SMART support, no manufacturer guarantees, no easy way to do low level recovery. They are ultra trashy consumer gear - Grandmas's storage interface of choice. As I and others have mentioned USB 2 or 3 hard drives or SSDs are better in every way except size and power consumption. Micro SD cards are usually better as seen in my example and are way better on power consumption. Why would I need to buy the very best one when USB 3 speeds should have been plenty? You do 18 KB/second or hundreds of megabytes per second when you get the extra special model? No. Just say no to flash drives.

Basically, I only use pendrives as install media, (or, sometimes, music & videos storage media).

18K transfer speed? I have not seen data transfer so slow since I had dial up! Something must be wrong with the drive or the port. You should be getting 100 MB read speed and maybe 25MB write. How old is the drive? I remember reading an article a while ago saying that over time flash drives slowly lose memory over time. There is a good chance that the drive might be corrupt. I have gotten away from flash drives. I don't even think I have one around here. I use external SSD's. They are cheap enough, but not quite as portable as one that will fit on a key ring. If you insist on a flash drive, make sure it has a warranty. I have had a few that have had a 3 year warranty. Odds are you will upgrade to a bigger drive with a better protocol before it goes south. If you want to go the SSD route, here is an adapter that I use. These are more stable and faster. Star Tec also makes adapters. If you have an extra SSD laying around it's worth the $9!

https://www.amazon.com/Cable-Benfei-...%2C273&sr=8-11