The Vertex 4 SSD from OCZ no longer uses a SandForce processor, but an Indilinx Everest 2 one, meaning that we do not longer have a lot of space used for over-provisioning and we should not have performance drops when using incompressible data. OCZ have also fine-tuned the firmware so performance delivery is different after the drive has been filled over 50% of it's total storage capacity.