I get a massive dip in performance as you should be able to see in Sandra. Every day it seems to get worse when i first set it up a few days ago i was getting the massive performance dip but the average 460MB/s.
I have tried all the SSD tweaks but nothing seems to improve performance
Please make sure that your storage controller is in AHCI mode, that the sandforce firmware is at the latest revision (should be 5.0.2 for sandforce 2200 series drives but this may change by vendor) , that you have both the storage and chipset drivers installed for your motherboard (for Intel this is the chipset software utility and the Rapid Storage Technology driver). You should also use CrystalDiskInfo to check the health of your SSD. SSDs should not be run in IDE mode or placed in RAID-0, if the OS was installed in IDE mode it should be reinstalled in AHCI mode after performing a SECURE ERASE on the SSD to restore some lost performance.