Machine is a late 2009 Mac Pro, so originally a 4.1 machine that has been firmware flashed to a 5.1. It’s currently running macOS Mojave, though it can be updated further, I know Sequoia is possible with the Open Core Legacy Patcher.
The machine has the following upgrades:
Dual Hex Core X5690 (3.46 GHz) (12 cores, 24 threads)
64GB of 1333Mhz DDR3 RAM
500GB NVME SSD boot drive
NVIDIA GeForce GT 640 (metal compatible, modded for boot screen support)
4-port usb3 PCIE card
3x OWC drive sleds (needed for modern HD mounting)
My main reason for letting this go is I was using the machine as a media server 24x7 and its quite power hungry. I’ve replaced it with an m1 Mac mini that is actually not as fast, but uses less power. This is still a very capable machine despite its age and would like to see it put to use. I have still have the original graphics card that will come with the machine in case its needed. $400 OBO