So you went from 1867 DDR3 ECC RAM to 800MHz DDR2?
I thought DDR3 started at 1066MHz.
It's OWC memory (32GB, 240-pin SDRAM DIMM 2048M x 72, Dual Rank ECC Memory Module Data Rate = 1333MHz).
From their website about the memory utilization in the mac pro:
"Apple Mac Pro 2013 models utilizes ECC non-Registered for 4GB and 8GB per slot options and ECC Registered for 16GB (and larger) per slot options. Any existing 4GB and 8GB ECC non-Registered modules cannot be mixed with 16GB and larger ECC-Registered modules and will need to be removed in order to utilize these higher density memory upgrade options.
Special 32GB module use information: Due to processor design and memory architectures, 32GB module utilization occurs at a bus speed of 1066MHz with Apple Mac Pro 2013 E5-16XXv2 4-Core, 6-Core, and 8-Core processor equipped models, 800MHz with factory 12-Core or after-market E5-26XX equipped models. Utilization of 2 or more 32GB modules minimum is recommended and utilization of overall performance with applications and workflows able to utilize higher available memory remains exceptional."
Since my workflow uses this much memory it is worth the sacrificed memory bus speed.