I’ve been testing 8GB of Mac Pro memory from two vendors: SATech and Other World Computing “Netlist Apple Certified”, for a total of 16GB—4X2GB + 4X2GB. Under full load with multiple copies of diglloydTools testing about 15GB of memory simultaneously, thus generating maximal heat, I’ve observed no ECC errors, though a test at a high ambient temperature is yet to be done. I’m not ready to endorse either vendor’s product, but I might do so when I’m certain my results are dependable. To be clear: diglloyd.com gets no commission from SATech or any other memory vendor.
If you are interested in the SATech memory, be sure to call them and specify “modules of the same quality that Lloyd Chambers of diglloyd.com is using”. Pricing on the SATech website might not be reflective of this style and quality of memory—my perspicacity in testing resulted in SATech providing me with what appear to be very high quality modules. I’ll clarify the part number and pricing with SATech sometime soon.
By swapping the two sets of 4 modules, I’ve determined that memory in slots 1 and 2 on both riser cards always runs about 10°F hotter than if the same memory is placed into slots 3 and 4. Keep this in mind if you do any comparisons of different brands.