I appologize if it's been covered before, but nothing came up when I searched the forums for iDCT. I am using xilisoft DVD ripper platinum to transcode some of our dvd's to wmv files for their Windows MCE computer and our Xbox360. Everything works fine, but while looking through the settings I noticed several options for iDCT and it got me to wondering which is best. The options are as follows: MMX (Intel P2, AMD K-6) Reference IEEE1180 (all processors) FPU (best quality, all processors) SSE2 (Intel P4) SSE/3DNow+ (Intel P3, AMD Athlon) I am mainly interested in the differences between Reference and FPU, but currently it defaults to SSE2. I'm guessing that I should just go for FPU since I would favor quality over speed, but was wondering if anyone had anymore info on this. I'm also not sure if this belongs in the dvd ripping section of the encoding section. It's ripping software but iDCT is an encoding setting.