I did not have any issues with this pair of CPUs. Both worked very well on the GIGABYTE 890GPA-UD3H. The problem actually came with the Cat 10.12 drivers. For some reason this driver set would not allow 3DMark 11 to run with either of these CPUs installed. It was driving me absolutely crazy and almost caused this review not to be ready in time to meet today's launch.
Originally I was certain that the cause was the CPU, as the test would fail at the first Physics test which is when the CPU first comes into play. In the end, though, it turned out to be the 8.80 driver that is in the Cat 10.12 package.
Thankfully there is an 8.79.1 driver that is also hiding in there. I was able to install that and miraculously things started working again. Unfortunately, as we mentioned, this issue ate up the majority of our testing time so we can only give you half of the story on the 840 today.