May be you have used different filesystem on the two USB stick ? unlikely, but let me ask about :-)
Both are ext4. The bootup started to slow a little and the Firefox
screens were stalling a bit, things that should be in RAM working.
On a hunch some upgrade caused a 1000 fragments I restored
from an unfragmented archive, I know most people will say Linux
doesn't have fragments, but a hunch nonetheless.
Then just increased the RAM cache on Firefox from 18MB to 100MB
to see what happens. Probably too big. Disk cache is zero.
I'll get to use it a little more over the weekend.
Thanks for the response.
Of course Linux filesystem do fragments, it also implements strategies to reduce fragmentation, but definitely do fragments.
That said, fragments should not be a performance issue when using flash memory, not like on conventional disks.
I would try to change journal behavior, data=writeback
as option in /etc/fstab or even to temporarily disable the journal using the option nointegrity
Also, the default commit time is 5 secs, (max time before to write pending blocks), you could try to increase the time to 20 secs
as option in /etc/fstab.
You can find further info about mount options using man mount
Also, I'm assuming you have performed a plain installation
on the USB stick and it's not a LiveUSB with persistence.