IDE Flash Disk Longevity

Hi,

My company has been using DiskOnModules from Nagasaki for the past two
years and recently we have discovered we are writing to the device way
to much (every second) and we are destroying these things in a matter of
months. (They have a limit of 100,000 writes and have wear levelling
build in).

We have been sourcing some other manufacturers as well as modifiying our
software to write only when we really have to.

I'm writing a test program where I want to write like 5MB at once to the
disk, read it back, verify it and keep doing this until destruction of
the device. This is in order to test the best product and if in fact any
are better than our current Nagasaki provider.

My question is that if I create a 5MB buffer and write it directly to
say /dev/hdc1 or something, then read it, is there a way to ensure that
this is actually written to the disk and not just cached in memory??

If this is more of a programming question than I'll post elsewhere.

Thanks for any help

Colin Goudie