If you are using BT for ATS trading, you might consider placing the signal file in a ram disk - http://www.techsnack.net/gavotte-ramdisk-free-virtual-hardisk
1. processing is faster than disk write/read
2. prolongs hard disk life by reducing frequent write/reads
3. signals not needed once read by BT so no need for permanent storage
You might also delete the signal file first before appending the signal to reduce BT processing time.