CPU Overload on Export

I see there are multiple post regarding this subject but couldn’t find an answer. I am getting a CPU overload error during Real Time Export only. I do real time while using outboard gear in mix. If I delete all outboard gear from mix and do in box there are no issues. On this last mix Task Manager in win 8 says I am using 25% of memory and highest CPU peak is 37%. I am currently using cubase 8.02 but was also happening in 8.01.

I probably have 25-30 tracks in this project all but one are Audio and I use a lot of UAD plugins. The interface I am using is Steinberg MR816csx and it is word clocked to Behringer ADA8200 which runs my compressors.

It seems that if I constantly change my buffer size either up or down I can get through export (no science used just change it) I started Buffer at 216 and now I am at 1600 during mix down 40ms input latency 41ms output latency.

Also: Using 1 Vsti (Vienna Imperial Grand)

Any one besides me still with this issue? Anyone have ideas as to solutions? Is it a cubase version issue?

I am Borrowing to Motu 2408 MK3 interfaces to see if the issue is the MR816.