Installing Mac OS-X El Capitan 10.11.1 in a 2006 MacPro 1,1

Here is a little write-up on how I installed El Capitan on my 2006 MacPro 1,1.

Before reading any further, please keep in mind that all my attempts to create a bootable USB stick, with the El Capitan installer, failed miserably. So I had to follow a different path to do it, which requires access to a Mac computer, which natively supports El Capitan. In my particular case, I used my early 2009 iMac. If you do not have access to a Mac which can natively support El Capitan, this method is NOT for you.

With this disclaimer out of the way, a quick description of the issue of installing El Capitan on those old Macs.

The 2006 and 2007 MacPros were extremely powerful computers for their time. They were the top of the line, professional machines from Apple and they still are quite capable. Unfortunately, even though most of their hardware is 64-bit, their firmware is only 32 bit. At some point in time Apple decided to no longer provide their OS-X with 32-bit firmware support (I do not exactly remember what was the OS-X version that broke it). As a result, those MacPros couldn’t use the latest releases of OS-X. Thank to some enterprising souls on the Internet, patches were developed, which allowed the use of later OS-X versions on those Macs. And those patches were easy to implement, my 2006 MacPro 1,1 was running Yosemite, before I decided to upgrade it to El Capitan. While some people are quite happy running OS-X 10.6 on their MacPros, I wanted to run the latest and greatest (or so they say) of OS-X, which is El Capitan or 10.11.1.

The following paragraphs describe how I managed to install El Capitan on my MacPro 1,1 and give you some troubleshooting guide on issues you may face after the installation. Please keep in mind that I can not be blamed if something breaks in your computer, by following the instructions below. Always have a backup of your data before doing anything dangerous to your system, and the instructions below are definitely not for those who do not know their way around the Mac OS-X.

OK, let’s start, here is a description of my systems:

1. MacPro 1,1 already running Yosemite (MP for short, from now on).
2. iMac early 2009, also running Yosemite and

All lines starting with a – are commands you should enter in a terminal window. Do not enter the “- “, only what follows it.

My MP boot disk is an SSD which is twice a day backed up to an external SSD disk, for security reasons. So I got this second SSD disk, let’s call it SSD_Ext, and move it to the iMac. I run App Store on the iMac and downloaded El Capitan installer. However, I didn’t allow it to install on the iMac internal disk. Instead I asked it to install the new software to the SSD_Ext disk, which was now connected to the iMac.

The installer went through it process and ended up by upgrading the SSD_Ext disk to El Capitan. I verified that by allowing the iMac to boot from SSD_Ext. I then changed the System Properties, instructing the iMac to boot from its internal disk (which I remind you has Yosemite installed) and removed the SSD_Ext from it.

I took the SDD_Ext disk to my MP (still running Yosemite). I opened a terminal window and issued the following commands.

– su

The system will ask you for your root password, enter it.

– cd /Volumes/SSD_Ext/System/Library/CoreServices

This will take you to the first place where the boot.efi needs to be replaced.

– chflags nouchg boot.efi

The above command will remove the protection from boot.efi

At this moment, I visited the following URL and downloaded the patched boot.efi needed to have the MacPro run El Capitan:

Scroll down until you find the “Download” paragraph and download either of the two boot.efi’s mentioned there. One is for a black background with a white apple and the other is for a white background with a black apple. Pick your choice, both work. I saved the boot.efi on my Desktop folder. I then went back to terminal and issued the following commands:

– cp /Users/john/Desktop/boot.efi .

That will copy the new boot.efi to CoreServices, overwriting the standard one. I then issued:

– chflags uchg boot.efi

This will protect boot.efi again.

While in the CoreServices directory, I then used Property List Editor to edit the file called PlatformSupport.plist . Since not all of the readers have this program, you can also edit the file with your favorite editor. I use vi, so here are the instructions on how to do it. Enter the following command:

– vi PlatformSupport.plist

Move your cursor down, until it is on the line saying “<array>”. Then press the letter “o”. A new empty line will open below the line your cursor was on. In the new line, enter the following:


Press Esc (the Esc button) and then enter:


This will save the file and take you back to the prompt. Now enter:

– cd ../../../usr/standalone/i386

This will take you to the second location, where you need to copy the boot.efi file. Just enter the following command:

– cp /Users/john/Desktop/boot.efi .

You are all done now. All that remains is to reboot your system from the SSD_Ext disk, to have El Capitan running. To do that, go to your System Preferences, Startup Disk and select the SSD_Ext as your boot disk. You may need to enter your administrator password two or three times, but that’s OK. Then click on the small apple sign, on the top left corner of your screen and your computer will restart.

There is an alternative way to select what disk to boot from. You simply restart your computer and when the boot sound is heard, press and hold the Option key on your keyboard, until a gray screen appears with all your bootable drives. Select the SSD_Ext (or whatever your external disk is called) using your mouse or your arrow keys and press Enter. The system will boot from that disk, in El Capitan.

Some remarks regarding El Capitan on your MacPro 1,1.

1. It is possible that some of your Internet Accounts are not copied correctly. So please check them out in your System Preferences. In my case, a CardDav account didn’t survive the upgrade, but that was easily fixable.

2. Most probably, you will not be able to boot from your Recovery Partition, which the installer has created on your SSD_Ext drive. The reason is that the boot.efi file installed in it, is the standard one, not the patched one. You can change that (and gain access to the Recovery Partition) by following these instructions.

Boot from your internal disk again, not from SSD_Ext. Open a terminal window and enter:

– diskutil list

This will show you all the partitions on all your disks. Find a partition called “Apple_Boot Recovery HD” which is on the SSD_Ext disk. Notice the last word in that line, something like “disk1s3”. Now issue the following command:

– diskutil mount /dev/disk1s3

The program will tell you that the disk is mounted. Enter this command to verify that:

– ls -l /Volumes

You should see a “Recovery HD” disk there. Issue the following commands:

– cd /Volumes/Recovery\ HD

This will take you into the Recovery HD disk. Issue:

– cd
– ls -l

In the directory, you will see a boot.efi file. You need to replace it with the patched one, so issue the following commands:

– chflags nouchg boot.efi
– cp /Users/john/Desktop/boot.efi .
– chflags uchg boot.efi

These will unprotect the boot.efi from the directory you are in, replace it with the patched one and protect the file again (just like we did above).

Then edit the PlatformSupport.plist file found in that same directory, following the instructions above.

You can now restart your computer and try booting from the Recovery HD.

3. El Capitan comes with a strange protection scheme called SIP, which is supposed to prevent overwrite of critical system files. That protection however, may prevent you from running certain programs, which may be crucial for you. In my case, the program XtraFinder which I use, couldn’t run due to that protection. To make it work, you need to disable the protection scheme. To do that, you have to boot from your Recovery HD partition, and from the menu on the top, select Utilities and then Terminal. When you are in the terminal window, enter the following command:

– csrutil disable

For the XtraFinder, it is not necessary to disable SIP completely, so you can enter the following command, instead:

– csrutil enable –without debug

4. An interesting side-effect of El Capitan, for those using two monitors connected to your MP, is the fact that now, the log in screen appears on your primary display, instead of the secondary one. For me, that’s a good thing.

5. Something strange I discovered yesterday night, is that the upgrade to El Capitan erased my trusty Airport Utility 5.6.1, which was inside a directory in /Applications/Utilities. So it seems that Apple doesn’t like us using the old but powerful 5.6.1 version. Thank God, it is easily available on the net, together with the Loader required for it to run on recent Mac OS-X versions.

6. I’ve been using the MP with El Capitan for three or four days now, and I haven’t noticed any significant issues. My Chronosynch scheduler has been disabled, after the El Capitan installation, but that was easily fixed. Also, a strange error message appears, from time to time, which is due to SuperDuper!, again nothing serious, google that issues, easily fixable.

I hope you’ll find these guidelines interesting and useful.

Addendum for problems with my second MacPro (December 25th, 2016)

A few days ago, I got my hands on a second MacPro 1,1. Same computer as the MacPro I’ve been using with El Capitan for some months now. The new computer came with OS-X 10.7.5 installed. The initial plan was to just make a copy of the boot disk from my old MacPro (let’s call it MacPro1 from now on) and install it in the new MacPro (let’s call it MacPro2 from now on) and have two similar MacPros.

Unfortunatelly, this didn’t work out as planned. The disk booted MacPro2 fine, but after a while, the computer hanged up. I tried to figure out what the problem was, but no luck. So I tried the next best thing. I had a copy of El Capitan install file saved, so I used that to create a bootable disk. The version of that install file was 10.11.4. Tried that, but that didn’t work either. So I downloaded El Capitan from the App Store again, and created a boot disk. That download was also 10.11.4, so I updated it to 10.11.6. But I asked the program to import all my settings from my MacBook. Well, that disk didn’t work either, so right now, I am in the process of redownloading and reinstalling 10.11.4 again. I’ll update it to 10.11.6 but won’t import the user settings from any computer. I’ll set it up from scratch. Wish me luck! I’ve had better ways to spend Christmas and next day, than playing with a crazy El Capitan!

Addendum of the addendum

Well, am I stupid or not? The MacPro2 came with only 4GB of RAM. Upgrading that to 8GB solved all my problems!