Fluctuating performance

[mauricev]

I see a lot of fluctuating performance in copying from a share (1Gb/s) to a USB 3 drive under Windows 10 x64, 1903 with 10.23. Sometimes, it can be pushing 70MB/s; other times, it seems stuck at 0. What might be causing this?

[mumen2]

It depends on the number of files.
USB Flash Drives have two types of memory: a little bit fast at the beginning for FAT and a slow one for data which produces a lot of latency and retrying to write. When you have too many files, the FAT ends up writing to the slow memory.

Each file comes to write the fat, so if you copy a lot of files to a USB stick, it's the disaster waiting to happen.

[xCSxXenon]

It's more likely overhead operations that are invisible to you. It's hard to say exactly what the cause is without trying some stuff

[mauricev]

"It's more likely overhead operations that are invisible to you. "

If I had been using Explorer, this wouldn't be happening. There's a bug in these overhead operations.

The overall copy speed is about .14 MB/s.

[Plerry]

... There's a bug in these overhead operations.

That's a bold statement.
You may very well be "suffering" a side effect of FFS's safe file-copying.

[mauricev]

It's also a very wrong statement and I apologize. The computer I was using has DLP software on it and that was tripping up the USB copying. Moved to another computer and now it's copying way better.