In DOS mode there is no DMA. so the writing/reading is not fast.smartdrive does some optimization in hdd reading or writing. it z kind of buffering. instead of writing into the disk, it is written into the buffer (RAM). so it speeds up things. hope u understand.
just copy the file from Win98 /win me installation disk. File name is smartdrv.exe . and just run it.
then go to i386 folder. then type winnt to start the installation.