Brand new sandisk extreme flash drive 16gb. Not sure why it's doing this?

So i ordered 2 of these, one for me, and one for my friend. The problem is i ordered these because i spent hours researching and this one has the best reviews from all over the place and everyone talks very highly of its speed. the packaging and reviews say that they read at 230~ mb/s and write 40-50~ mb/s. Mine was only reading 200 mb/s and writing at only 20mb/s at first. 

So i thought maybe i missed the usb 3.0 drivers or something and went to asus (my motherboard’s manufacturer) website and downloaded the 2 drivers under the usb menu called “ASMedia_U3_FW_update”  and “Intel USB3.0 Controller Driver V2.5.0.19 for Windows 7,” and i also updated my bios version because I read a lot of people’s solutions were simply updating the drivers. but then i tried it again and now it’s only reading 40mb/s and writing 19mb/s. Also, i’m not using the secore crypt or whatever the program the drive came with.

I have a corsair carbide 500r case and i know i plugged into the usb 3.0 port(in fact i think they’re all usb 3.0).  What happened? What did i miss? did i do anything wrong? I’m just filled with all sorts of confusion right now.

the following is my build:

asus z87 pro
i5 4670k
windows 7 64 bit
samsung 840 pro ssd

Thanks in advance!

the packaging and reviews say that they read at 230~ mb/s and write 40-50~ mb/s. Mine was only reading 200 mb/s and writing at only 20mb/s at first. 

 

That’s normal. Those are just approximate numbers. It’s also possible that the testing made was at an ideal scenario. But you got close to it. 

Right, but the problem now is that after i updated the drivers for my cpu and bios it’s now only reading 40mb/s and writing 19mb/s. and it’s vidible too it’s not just numbers change where the speed isn’t affected because it really takes a lot longer now. 

how do i fix this? i have the older version of bios but i don’t have the older version for the drivers.

:smiley:  Hello!

Please try the Flash Drive on other Computers, to define the problem.

View all System Restore Points.

See also the CCleaner / Tools, Restore Points.

Regards, Alfred.   (Google Translate).