Hi, all! I aquired this Mac Pro, which happened to come without a HDD. I haven't been able to install either Yosemite, El Capitan, or Sierra on it (using several guides), so I'm kind of curious which version this actually is. This is what I can find about it: First ricer board has: 2x 2GB RAM 2x PCIe ports Second ricer board has: 4x 2GB RAM Looks like they came from the factory like this. The motherboard has a sticker which says: 9N735003QVNBA 630-7608 The bottom of the case says absolutely nothing of value. I hope you can help me, so I can get some kind of OS installed on this Mac Pro. Thanks a lot!