On Wednesday, 25 November 2020 17:37:15 GMT Dr Rainer Woitok wrote: > Greetings, > > since my old 64 GB Verbatim USB sticks became too small, I bought two > new 128 GB Philips sticks. Because I need to read and write them on > both, a stand-alone Windows laptop (not connected to the internet) runn- > ing Windows Vista and Cygwin and my Gentoo laptop, I encrypted them with > old TrueCrypt on the Windows box, using them under Gentoo in TrueCrypt > compatibility mode. > > This worked well with the Verbatim USB sticks (which probably are USB > 2.0), but while reading the new USB 3.0 Philips USB sticks is signific- > antly faster than reading the old Verbatim USB sticks, writing to them > is slow as hell under Gentoo. And writing to the Philips USB sticks on > the old Vista laptop with USB 2.0 ports clearly outperforms writing to > them using the Gentoo laptop's USB 3.0 ports. > > This could be a problem with TrueCrypt/VeraCrypt or with somehow miscon- > figured USB ports. To check for the latter I provide below all kernel > configuration variables I regard USB related in the hope that some know- > ledgable people might find a glitch in there:
Check dmesg to see if initialisation of the USB 3.0 drive throws up any errors. Then check 'lsusb -t' to make sure it has been recognised as a USB 3.0. If write operations without TrueCrypt/VeraCrypt are equally slow, then obviously the problem is not with encryption. I've read in a number of articles the erase block size on most USB flash (NAND) is 128KB, which incurs a lot of operations on a write, when using Linux with its 4K size sectors. Partitioning the USB drive to use 128KB sectors and then aligning the fs on it should improve matters. I found this article which mentions an experiment with ext4 fs. A more effective search should hopefully bring up examples on FAT fs. HTH.
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