Why is my USB 3.0 flash drive so slow?

[Jerry_82]

I purchased a 128gb Sandisk Extreme USB 3.0 flash drive a few days ago. It's advertised up to 245 MB/s read speeds and up to 190 MB/s write speeds. I understand it says up to but I'm getting a consistent 75-78MB/s write speed. I'm using a USB 3.0 port but the highest I've hit was around 84 MB/s. It's not even close to what it's advertised. Some people say the larger the file, the harder the USB will work thus faster the speeds. I'm getting these numbers from transferring a 110gb folder. That's the whole freaking USB storage. How can it possibly get bigger? I'm not sure if this is supposed to be the speed and the "up to" is just a test speed not a real consumer use speed or if something is wrong.

I just found out after I finished, the USB was very warm if that affects anything or if it's a heat problem? I mean I did just copy a 110gb file over

Someone also brought up the format. When I plugged my USB in I noticed it said Fat32 if that helps.

 

[Emerald]

It could also have to do with the transfer speed of your source.

 

[rkzhao]

I think someone else had posted about temperature concerns with these flash drives. I don't have any personal experience so I don't know.

From my limited understanding of these drives, they are set up pretty similar to a SSD. Thermal throttling due to heat could be a factor. The drive working "harder" only means that it's going to get hotter.

Also, I'm assuming this is the first time you've transferred anything to the drive? The drive might need to be preconditioned before hitting closer to the claimed performance. Now that you've pretty much written over the full drive, you could try transferring something again and seeing what the speed looks like.

 

[Jerry_82]

So I transferred a 2gb movie to my flash drive now to see if it's changed it was the same. I deleted it and tried again but it was a little different. It hit a speed of 120+ MB/s for like a second or two then dropped to a speed of 53-59MB/s. any ideas how to increase the speed closer to the advertised max?

 

[Jerry_82]

Ok I just tried the movie again a few more times and now I'm hitting 170MB/a speeds. Thanks so much guys. I guess the preconditioned theory was correct.