This guide's intro has changed multiple times over years as the landscape has radically altered for the Mac and after four years my perspective has changed. It has been continuously updated for over four years and will continue to be updated as long as there is a community to make new discoveries. This is less a how-to guide/manual than it is a roadmap to primary sources by other brilliant people, written to be accessible to both new and advanced users. The information is out there but knowing what is possible, what questions to ask, and where to find it isn't nearly as easy. The largest/most-complete guide to all possible classic Mac Pro upgrades covering OS, Firmware, GPU, CPU, Storage, USB and Network upgrades.
Update Recovery Partition on Unsupported Macs.Fan / Heat Sink / other case part Replacement, Liquid Cooling.3D Printed Replacement Hard Drive Trays / 2.5-inch Adapters.Recommended Places to go for Monitor Recommendations.Apple Thunderbolt 27-Inch Cinema Display (and the LED 27-inch Display).Control Brightness on a 3rd Party Display.Why you can go HDMI to DisplayPort but not the inverse.Dual-Link DVI Displays & Modern GPUs (and the 30-inch Cinema Display).Summary: Getting the most out of your SSD.Making PCIe drives appear as internal Drives.Can I use a card that isn't listed that hosts multiple NVMe drives?.Installing a 2.5x height GPU (such as a Radeon 590x).I want a GPU that has a boot screen and is Metal (Mojave 10.14+) compatible.Radeon Navi 21 GPUs (Radeon 6800 - 6900 XT).OEM EFI Bootable Cards / Aftermarket EFI Bootable.Microarchitectural Data Sampling (MDS) vulnerabilities.Instruction Sets, SSE 4.2, VT-x/EPT, AVX/AVX2.Running Apps from unidentified developers.OpenCore: Codec acceleration, boot selection, and unpatched OS updates.Upgrading to Catalina: OpenCore vs DosDude1.
I figured I would reinstall my old 2.8 GHz processor (which I did) and then try to downgrade to the 2009 4,1 EFI so I could put the dual processor tray in and upgrade everything (back) to 5,1. In "About This Mac", the EFI was still 5,1 with the dual processor tray from the 4,1. The temps seemed ok for everything, but I wasn't doing anything and the computer was only on for about 10 minutes. The BoostA fan was blowing at about 1600-1700 RPM (about two times the normal rate) and it was LOUD.
When I replaced my single processor tray with the dual processor tray, all of the fans except BoostA stopped working. The problem is that the dual processor tray was from a 2009 MacPro 4,1 with 2 x 2.26 GHz.
Then I saw a dual processor tray with 2 x 2.26 GHz on eBay and figured I'd upgrade from a single processor to a dual processor, and would replace the 2 x 2.6 GHz to 2 x 3.46 GHz- from 8 core to 12 core (which I haven't done yet). Incidentally- RAM = 4 x 8 GB went from 1066 MHz to 1333 MHz. I upgraded it to the X5690 six core 3.46 GHz processor. Initially, I had a single processor tray with a 2.8 GHz quad-core Xeon processor. I have a mid-2010 MacPro 5,1 (Boot Rom version: 03).