To get to the RAM, we had to open the case and remove the fan assembly—one more step than the Mac Pro, so we'll kick a point to Apple for being slightly easier in this respect.

Once you do get to the treasure chamber, the Z820 has some mighty impressive upgrade opportunities.

16 DIMM slots are laid out with 4 individual channels over 8 slots per CPU. Fully loaded, you'll be sporting 512 GB of 8-channel ECC DDR3, up to 1866 MHz.

You'll also be out over $10,000 for your efforts.

For what it's worth, our unit came loaded with 4 sticks of Micron 4 GB DDR3, for 16 GB total.