What would be faster, transferring a zipped file to flash drive then decompress there or transferring the unzipped files

compressionfile-transferhard driveusb-flash-drivezip

Taking in consideration the time it would take to decompress the zip folders once copied to a flash drive, what would be faster? Copying the compressed folders to a usb flash drive then decompress them on the flash drive or just copying the uncompressed folders to the flash drive.

Don't take in consideration the time it takes to compress the files since the files are already compressed before copying. I can copy either from a USB HDD or from an SSD to a USB flash drive (both supporting USB 3.0).

In this specific case I want to transfer 9 zip files which have in total 115,518 files, most of the files are really small image files (the 9 files in total amount to 15Gb uncompressed and 10 Gb compressed).

Best Answer

Taking in consideration the time it would take to decompress the zip folders once copied to a flash drive, what would be faster? Copying the compressed folders to a usb flash drive then decompress them on the flash drive or just copying the uncompressed folders to the flash drive.

Probably the latter.

Remember that decompression and other such things are done by the computer's CPU. You can copy data into a drive (be it flash or HDD), and you can copy data out, but you cannot tell the drive itself to decompress it – or do anything else, really.

So your first plan would involve:

  1. Copying 10 GB of data from disk to flash
  2. Reading those 10 GB back from flash to RAM
  3. Decompressing it
  4. Writing 15 GB of the decompressed data from RAM to flash
  5. Deleting the useless compressed files left after step 1

The second:

  1. Reading 10 GB directly from internal disk to RAM
  2. Decompressing it
  3. Writing 15 GB of decompressed data to flash

Notice how the first plan involves twice as much reading&writing. But not only that: in reality, steps 2-3-4 wouldn't happen in order but in parallel – which makes the process faster when reading from one drive and writing to another, but much slower when the same drive is doing both reads and writes.

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