I have a very simple timeline that consists of a ProRes clock and a ProRes programme (not edited in any way, just the original source file in it's entirety).
When exporting to MXF OP1a AVC Intra (matching the ProRes frame rate, frame size, field dominance, etc...) the performance is incredibly slow, I don't believe this to be a fault with the workstation but something to do with the AVC Intra encoder as if you look at the task manager, the CPU is only being utilised at 5% and the RAM usage by Premiere is at no more than 2GB max, the GPU also isn't doing anything. Exporting a 45 minutes programme takes around 80 minutes.
If I export the same timeline to another format, such as DNxHD or XDCAM, the RAM usage goes up to the maximum the system will allow for Premiere (around 12GB) and the CPU usage increases to around 50%, only being limited by the amount of RAM in the system. Export time for the 45 minute programme is around 10 minutes.
The system itself is a HP Z820, 2x 8c 2.6Ghz Xeon Processors, 16GB RAM, 3x HDD RAID0 disk array (operates at ~500MB/s) and a Quadro 6000 gfx card. All drivers and software are up to date, running Premiere 7.0.1.
Is this just a limitation of the AVC Intra encoder that Premiere uses?
Have you tried exporting the sequence using AME, if not check and see if that makes any difference.
I have tried that and the export time is the same if not very slightly quicker.