Can't transfer files to USB

I can't transfer any files that are bigger than 1mb to any of my flash drives. I've tried many different sizes and types of files using different USBs and different ports and even formatted the USBs. I can transfer files in between my two internal HDDs without any problems. Also it seems if the file system is FAT32 it transfers files normally. When the file system is NTFS it has a speed of...