I just changed my power supply and when I boot it says till i use 40 conductors wire and not 80 cond. w. it will be switching from d2 to ultra33 mode what does it mean and what should I do
This is not a bad thing. 80-conductor cables have better signal integrity, and both drives and controllers can sense (by the additional ground wires) that such cables are in use. The d2 reference is not one I'm familiar with, though. Normally, 40-conductor cables will support Ultra-33 mode. Most new hard drives are Ultra-100 or 133, but nearly all CD/DVD drives are still Ultra-33 (a 52X CD drive is still under 8 MB/second data transfer). Still, I use 80-conductor cables for better signal quality, where possible.