"2009 Mac Pro CPU upgrade experience
Just thought I'd drop you a quick report on my recent CPU swap on my trusty 2009 Mac Pro.
Although I'm more a hobbyist than a true pro when upgrading (from) my Power Mac G5 back in April 09 I chose the Mac Pro dual CPU 2.26GHz model as it wasn't much more than the quad core and it was cheaper to bump up the RAM with prices at the time because of the extra slots. I've always gone with desktops (Sawtooth G4 then the G5) so I could upgrade the GPU over the years as I'm one of the small and hopefully growing number of folks who also really enjoy playing games in OS X. Although I wasn't regularly maxing them out the extra cores came in handy encoding H264 (Handbrake) and with Logic 9 then X and meant I could encode in the background whilst playing games and working in other apps.
Over the years I've owned this machine I've added loads of storage, driverless PCI-E cards for eSata Newertech (this 6G one?) and then USB 3.0 (Innatek) and swapped the GPU from the original configure to order Radeon 4870 to an Apple upgrade kit Radeon 5870 and then, around a year ago, to a Sapphire Radeon 7950 Mac Edition so I could upgrade to a 1440p display. I've tended to upgrade to a new Mac after around 5 years but the new Mac Pro cylinder is more focused to a few specific markets and only the D700's would be any upgrade over the 7950 for games which price wise would make even a CTO Quad core machine well beyond my budget. I did think long and hard about a Retina iMac as the screen on that is truly beautiful but again even increasing my typical budget and maxing the CPU and GPU it's very similar to what I already had GPU performance wise and only really offered the massive boost in single core speed and I/O with the faster SSD. (I'm currently using a Crucial M500 480GB as a boot drive myself.)
I already knew of the Mac Pro 5,1 'unofficial' firmware updater (for Mac Pro 4,1) and had read plenty of guides online and seen videos since folks started attempting these upgrades. (i.e. YouTube video on 2009 Mac Pro 2009 8 core Nehalem to 12 core Westmere upgrade) but I'd always been put off by the cost of the chips and the risk due to the taller chips with IHS (Integrated Heat Spreader) installed. The last CPU upgrade I did was on my old Sawtooth G4 so I'd no experience of swapping out Intel chips, but when keeping an eye on 5600 series Xeons for sale as these plummeted in price I came across a seller in the USA that was offering kits with the IHS removed. This sounded like a lower risk option and also means you don't have to modify the heat sink connectors so eventually I decide to risk it with the 3.06GHz x5675 kit. (Xeon X5675 specs page.) I choose these as they have a TDP of 95W (the maximum Apple used in dual CPU machines) and were even offered by Apple as a CTO option in 2012. I know the faster 5680 and 5690 chips do work but was concerned about the higher TDP of 130W in case I also upgraded the GPU again later down the line and although it is easy to do with third party apps I didn't really want to have to mess around with the cooling fans settings or add a second power supply - I liked being able to leave them all at the system defaults.
For the firmware flash I used a spare hard disk to install OS X 10.8 as I'd read it was a problem running this in later releases. Thankfully I'd already downloaded the file from Apple as it appears the web address the program uses has changed. (Here's Apple's 2010 Mac Pro EFI Update 1.5 (MP51.007F.B03) D/L page. Unofficial updater was from Netkas forums.) Simply having this disk image on the desktop allowed the program to run and this went ahead smoothly. I used my machine a few days like this before ordering the kit. These arrived fairly quickly so I cloned all my disks and removed them and installed a spare disk with a fresh copy of Yosemite installed as I figured I may have to do some force power downs.
Once the CPU tray was removed I took the opportunity to use an air duster to clear the dust - especially around the North Bridge heat-sink. I'd read the comments you had received on the heat-sink (plastic) retainers failing (notes/pix here) so looked for any sign of this - my temps always seems to be around 60 degrees Centigrade and thankfully these looked OK so far. The Torx driver supplied in the kit was easy enough to use to remove the heat sinks and following the Apple service guide I removed the old chips and applied thermal paste using the pattern shown. Probably a little foolishly I installed both CPUs together as I had no dust caps to cover the empty sockets and was concerned about dust in the rest of the case getting into an open socket. Being particularly worried about crushing the chips (a larger risk in an 09 model if you use the taller regular chips with the IHS present) I must have left the heat sinks too loose as I got a flashing LED on the front panel. What I had forgotten to do was make a note of what the LED flashes on a POST failure meant so I had to grab my iPhone to look them up online. The initial issue was a RAM error. I had taken out the dimms for CPU A when installing the heat sink to try and make sure it went on level. I found that one dimm was not seated correctly so fixing that stopped the LED flashing.
The second time I just got a black screen and fan noise. Suddenly I noticed the plastic standoff for CPU B was still on my desk...(oh no!) I figured I must have crushed that CPU for sure but on removing the heat sink I was relieved to see it look fine. I cleaned the CPU and heat sink again, re-did the thermal paste and tried again. This time I tightened both heat-sinks more - Apple's guide gives torque setting I couldn't measure but does also say finger tight and then a little more. This time the machine booted but only with one CPU and 12GB (half) of the RAM recognized. I knew now that this meant CPU B was not correctly installed. Removing the tray and tightening the second heat sink again I tried once more and success! Both CPUs were recognized and all the RAM. This was still only running at 1066MHz and I knew I had ordered 1333MHz ECC chips when last upgrading the RAM. I had already read that a PRAM reset may be required to fix this and indeed this worked fine.
I'm now putting the machine through its paces but so far the temperatures seem nearly identical to before. Handbrake is making use of the extra cores and my game tests are showing about 30-35% improvement in single core (as per the clock speed increase) and most of all better minimum fps - the original chips did remarkably well given the low stock clock speeds but you would see the odd slow down now and then. The Unigine Valley benchmark results at 1440p are now near identical (very slightly better) than what I have seen listed for the maxed out 4.0GHz Retina iMac with mobile R295x so for a fraction of the cost of upgrading to one of those machines I really can't complain!
I figure barring any major failure I should get a few years more out of this machine possibly with a GPU upgrade along the way as the latest chips that would represent a decent upgrade over the 7950 (Nvidia GTX 970 and 980) are now back to just the two 6 pin power connectors. I also see you can now install one of the blade SSDs removed from a Macbook Pro or Air using a cheap PCI-E card for faster I/O (like this Sintech M.2 Adapter Card?) and an up-to-date Airport and Bluetooth module for handoff support. I thought my Sawtooth G4 back in the day had an amazing life span though upgrades but it really has been amazing the usable life span of these machines.
Best regards, Matthew"