Being a stickler for performance, the first things I do with a fresh Windows install is fix the swap file size, turn off all the fancy animations and shut off unneeded services. I also make sure to switch on write-caching for all my USB drives as I use them — the option is better known by its user-friendly name "Better performance". Turns out the benefits might only be as high as five percent. At worst, it can actually hurt transfer speeds.
Benchmark images: 7Tutorials
The folks over at 7Tutorials decided to run a few benchmarks on this feature to find out if the annoyance of having to select "Safely remove device" every time you yank out a USB drive is worth the trouble. The tests were carried out with CrystalDiskMark and three drives: a Corsair Voyager GT 16GB, a LaCie 1TB external hard drive and a 2GB "no-name" thumb drive.
For the Corsair and no-name flash drives, read performance dropped less than five per cent and about one per cent, respectively. Surprisingly, both experienced a boost in read performance, but it was never larger than one per cent.
How about the hard drive? Maybe its use of traditional — and slower — magnetic media might see some bigger differences. Well, have a look for yourself.
Don't be afraid to wear your unimpressed face.
The moral of the story? If you're not completely insane about the performance of your external USB drives, save yourself some hassle and just keep them on the "Quick removal" setting.