Definitely recommend getting an SSD/NVMe to make thing thing more useable. Even though the SATA ports on these things are capped at SATA 2 speeds, they still feel plenty fast. Throwing in more RAM would be good too, depending on what you have already in there. I think you can do a max of 48GB triple channel or I think 64GB dual channel on the single CPU one.
If you don’t have a good video card, I would recommend getting one—specifically an AMD one since Nvidia drivers don’t exist past High Sierra. While I have wanted a little more performance from mine, I have a 4GB low profile RX560 and it does the job (just don’t expect to play any newer AAA games at high settings past 1080p). There are also two plugs on the motherboard that you can plug in power if you get a card that needs more power than just the 75W off the PCIe slot.
Quality of life upgrades you can get:
- Wi-Fi/Bluetooth card: you’ll have to see what/if your tower has one. I didn’t think mine did but it was useable up until Monterey. Guess they dropped drivers that this card uses past Big Sur.
- CPU upgrade: you can get these CPUs pretty cheap(~$20), but you’ll need certain tools to take the heat sink(s) off. Make sure you get the right ones for the right Mac Pro config. I tried to use one of the dual CPU chips in my single CPU config and it ran the fans at 100% all the time. Ended up just putting the stock one back in. While these chips are cheap, don’t expect anything to compete with the current CPUs.
- USB cards: you can definitely put more USBs in via the PCIe slots. Don’t know if they support power while sleeping though.
I love my Mac Pro 2009, and I’m definitely going to keep it as a plex server or something… but I’m ultimately looking to get an M-series MacBook to replace my current 2014 MacBook Pro. Can’t beat portability lol. You can definitely squeeze more life out of these things by going with the OpenCore route (Google Martin Lo OpenCore—they are a godsend) and getting them up to current, but it how far are you willing to go to make a decade old machine run things designed for this decade’s machines? That’s where I threw in the towel—I don’t have the time anymore to keep trying to tinker making sure an update won’t brick my computer because of driver/kext support.