12 Core Upgrade - 2009>2010 Mac Pro 4,1 - El Capitan


macrumors newbie
Original poster
Dec 10, 2015

Just wanted to share my experience with a 12 core upgrade on a Mac Pro 4,1.

Using El Capitan the 2009-2010 firmware tool would not run, kept getting 5570

Downloaded the Mac Pro EFI 1.5 Firwamre (https://support.apple.com/kb/DL1321?locale=en_US)

Mounted this on the desktop, then ran he 2009-2010 Firmware tool. Shutdown Mac Pro and then powered on holding down the Power button then releasing at the end of the Tone.

This did not work. Checked /var/log/system.log, discovered some permissions issues.

Booted in Recovery Mode - Shutdown Mac and then Powered up Pressing Cmd + R

Once in Recovery mode, run the Terminal App from the Top menu.

ran the following command to disable enhanced security, this is apparently default in El Capitan.

# csrutil disable

Then rebooted back into OSX. Mounted Mac Pro EFI Firmware, then ran the 2009-2010 tool successfully.

Powered Mac off and powered on holding down the Power button then releasing at the end of the Tone.

I could see now that the firmware was taking place, boot screen bar was enlarged and CD tray ejected.

Could see the system was now at 5,1 after update after booting back into OSX and checking About Mac/More Info.

As for the processor upgrade, I used 2x 1mm Nylon washers on each bolt/screw to sort of match the height of heatspreader on the X5680 CPU's.

Added some extra 1mm thick thermal heat padding to the edges of the heatsinks to make up the gap to the board.

Squirted on some fresh thermal grease/compound (pea size) onto the CPU after installing in socket. Cleaned the copper bases of the heatsinks, with some rubbing alcohol.

Slowly lowered down the heatsink fan plug side first. Tightened the screws with 3mm Hex Wrench (Allen Key), to finger tip tight.

Put ram back in and slotted board back in.

Now shows 12 cores in About Mac/More Info :)


macrumors 68000
Jan 12, 2014
Congratulations for having upgraded your Mac Pro. Multicore performance until the cows come home.

I would propose in addition an Apple/Samsung PCI Express-SSD so you can get adequate i/o performance.


macrumors newbie
Apr 25, 2018
You wouldn't believe what people
charge for delidding. It's not that hard.