When it comes to flash drives, SD cards, and usb card readers, you pay
for performance. 7gb in 25 min is about 4mb/s, which is class 4 SD
card speeds. If you look up Kingston 16gb SD cards on Newegg, you'll
find class 4 cards for $12 while class 10 cards (10mb/s) are $20.
This is a common problem for photographers. For example, a few months
ago, I upgraded from a 32gb SD card to a 16gb SD card. Sounds like a
downgrade, doesn't it? Except that the 16gb card writes at 40mb/s
while the 32gb card only did 15mb/s. I even had to upgrade to a usb
3.0 card reader, because the fastest usb 2.0 card reader I owned maxed
out at 15mb/s.
The only flash device that crapped out, all over the floor, was
Kingston's. My first and first impressions/experience. What happened
was I'd simply leave the thing plugged in for MoJo to mysteriously
appear in the NeitherWorld of SolidState. Although, to Kingston's
credit they did replace the unit (16G) promptly and largely without
pain -- I'm not actually sure with what since whatever they gave me
isn't what appears the same as ordered. For crappy "Class Standards",
I suspect, along with all my USB flashdrives, with a well-optimized
drive just prior to writing to solidstate, I can get somewhat
acceptable rates broaching 10Mb/sec. Non-photographic intents,
occasional non-networded trx <> computers, read speeds are still Lady
FutureWorld GaGa, at least for me;- wasn't that long ago the pain that
often lingers was I was writing DVDs to get something across the room.