In all cases the flash drive was completely zeroed out and hence there was nothing to mount. I'll have a look into fio once I have time again to play with this. Might be 2-3 weeks though because of vacation... On Fri, Jun 17, 2016 at 9:02 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, Jun 17, 2016 at 08:30:47PM +0200, Michael Schaller wrote: >> Greg, for my initial tests I did a sync afterwards and it finished >> immediately on Linux and Mac OS X. Sorry for not mentioning that >> earlier. > > That's really odd, and is not normal for either OS. > >> Furthermore 270 MB/s is the advertised write rate of the flash drive. >> Mac OS X and Window can both write at the advertised speed and Linux >> only reaches ~45 MB/s (~1/6th). >> If someone is interested into digging deeper into this issue I can >> look into shipping one of these flash drives... > > Are the devices already mounted by the os? If so, your mount options > will have a huge influence on this. Try unmounting them first before > doing "raw" 'dd' copies to them. > > Also, look into using the fio tool to test the real speeds here, dd is > not the best tool for it. > > thanks, > > greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
