Btest - more than 50% consumes flash in tools-profile, why?

I do btest from rb750up to rb2011, Download is ok and also speeds are ok. But when I do upload test, the speed goes from 40mbit/s to 1mbit/s, interface doesnt shows speed…
When I looked in tools-profile during upload test, it showed that more than 50% of cpu is consumed by flash.
What it means? It doesnt shos this during download, which shows right speeds…

Nobody can explain? why flash consumes so much CPU during btest?

Bump!!!

there is a problem with flash using a lot of cpu but mikrotik is not doing anything.

Maybe its logging a ton of errors? Would explain why it slows down too…

yeah sure, two truck of errors…

Is that problem of rb750up alone, or other routerboards are also affected?