You really dont and should not mix models/densities on that platform. If you have 32GB then you need to either add 32GB more or go to 128GB which likely means replacing the current sticks. I would suggest replacement.
gotcha, that makes sense.
Fewer is (slightly) better generally as long as the config is optimized. On a dual CPU Z820, 64GB (8x 8GB ECC reg) is also a good setup along with the 128GB one Eric suggested.
Also see no problem with just adding another 32GB (8x 4GB) as long as they're matched for type (all registered or unbuffered but not mixed).
Thanks Alex, I'll probably add an additional 32GB (8x 8GB ECC reg), unless my boss will spring for the 128. I just got this system couple months ago and I'm more than impressed with the performance. And like I said earlier, I have some $$ left over and its a use it or lose it, so more Ram seemed logical. May not have capital coming my way again for a while.
Thanks again for the input, much appreciated.