This is my first post, have been using FCPX from day one... and read this site all these years.
I don't have any hard facts but it seems to me that transcoding to h.264 is much slower in 4.3. I export HD 1080 timeline that is usually around 2-3 hours to 8000kbps h.264, single pass with High profile and Cabac. I have tried Main profile and Cavlc... does not seem to make much difference in speed.
It used to take about 50% less then real time before I updated to 4.3 but now it takes about 10% more then real time... that is a huge difference. I have reinstalled Compressor but that didn't make any difference... I have played with different settings but I can't figure out why it is taking much longer to transcode.
If anybody has any insight I would really appreciate it! I make 3 of these export for vimeo a week and then I actually make 3 additional export that are a little longer for archives and use the same settings.
My Computer is iMac (Retina 5K, 27-inch, Late 2015),
4 GHz Intel Core i7
32 GB 1867 MHz DDR3
AMD Radeon R9 M395X 4096 MB