Newly bought Kingston 3.0 flash drive stops at times

I just bought a USB flash drive kingston data traveler 3.0 16gb recently , and when i format it as NTFS , and start storing some files in it , i start to see its writing speed is very low , just like 25 or so per sec , 33.6 with Asus 3.0 USB boost , and while im transfering files , i noticed that it stops every once a while , then continue. And this problem only occur when its formatted as NTFS , its fine when its FAT32 .... but if its using FAT32 i cant use more than 4gb for readyboost ... and i have tried to test the speed while its being used for readyboost and not , same result , same problem , only thing is the speed is faster while its free from any duty , should i worry about it or this is very normal and have nothing to worry about ? i just bought it for 7 days , mainly for readyboost , i can totally exchange it for a new one .... but i bought it from my aunt , she sells these things for a living so i needed to ask first before i blame her for it.

I have a Kingston 64GB and experience extremely slow transfers. Thought the drive was bad but after searching found it to be a pretty common problem with many complaints. Mine is so slow I won't even use it.

........ kk .... guess i'll never buy kingston stuffs ever again , ty ....and i dont even think its running on 3.0 system , when i plug it on 2.0 port it give me the same speed , same problem