USB 3 write speed fluctuates in Windows 10
I am using a 1TB SSD drive for file transfer between two Windows 10 computers that i connect using a USB 3 adapter and ports. I copy files from System A to the drive and then from the drive onto System B. I've performed one transfer from A to SSD to B at relatively constant rate of 180 MB/s. Once i've emptied the drive onto System B i needed to perform another transfer from System A to the drive and the speed of writing from A to SSD started to fluctuate similar to this: USB random write speed
If the first transfer was fine then it is not a hardware limitation. Could there be a process in Windows that affects cache on an SSD/USB drive ?
One thing to note is when plugging the SSD thorough USB into System A for the second transfer it did show a second 0.5 GB drive called System Recovery that i did not create. Could this be a symptom of what could be causing it?
If not, is there a way to flush the SSD cache ?
Solution 1:
You ignored two possible bottlenecks:
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You successfully kept the type of drive of your system A a secret. If the drive is a hard disk drive you might deal with defragmentation and files of varying size in system A which could heavily affect transfer rates.
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If the first transfer was fine then it is not a hardware limitation.
Wrong. Once your SSD is filled up the write process on the SSD will slow down due to the necessary time-expensive erase functions. Your SSD firmware cannot react as fast in erasing as the operating system sends TRIM commands to the drive when you are deleting the content of your transfer SSD to be able to copy another round of data on it.