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Project Alice

macrumors 68020
Original poster
Jul 13, 2008
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Post Falls, ID
Hi all, as the title suggests I am wondering if a Core 2 Extreme QX9775 would work in a 2008, 3,1. According to this thread, any CPU with an SLA sSPec should work. The QX9775 is an SLA. The QX9775 seems to be identical to a X5482 Xeon, except it has an unlocked multiplier. Which leads me to the next question:
Assuming the QX9775 works, would the Mac Pro's EFI allow me to overclock it? It would probably be possible under Windows either way, but it would be nice for the entire machine if I could set the variables manually in the EFI.
I currently have a dual e5462 2.8Ghz Mac Pro, so overclock or not 3.2Ghz would be a nice little jump.
 
Hi all, as the title suggests I am wondering if a Core 2 Extreme QX9775 would work in a 2008, 3,1. According to this thread, any CPU with an SLA sSPec should work. The QX9775 is an SLA. The QX9775 seems to be identical to a X5482 Xeon, except it has an unlocked multiplier. Which leads me to the next question:
Assuming the QX9775 works, would the Mac Pro's EFI allow me to overclock it? It would probably be possible under Windows either way, but it would be nice for the entire machine if I could set the variables manually in the EFI.
I currently have a dual e5462 2.8Ghz Mac Pro, so overclock or not 3.2Ghz would be a nice little jump.

Mac Pro don't have any overclock support and probably don't have the ID for QX9775, at least I never saw it.

Unless you can get it really cheap elsewhere, with the price of one QX9775 on eBay ($239,99), you probably can buy a basic MP4,1 if you search a little, the price of two will get you a nice MP5,1.
 
Mac Pro don't have any overclock support and probably don't have the ID for QX9775, at least I never saw it.

Unless you can get it really cheap elsewhere, with the price of one QX9775 on eBay ($239,99), you probably can buy a basic MP4,1 if you search a little, the price of two will get you a nice MP5,1.
Yeah.. I saw that after I posted this lol. I don't understand why the Xeons are like 10 bucks a pop and the QX9775 is priced like that. I might end up just sticking a couple X5482s in it since they're cheap.
 
in theory they should work as they are C0 stepping however I dont think its ever been tested

however as @tsialex mentions they are silly expensive (mostly because they are a rare extreme edition CPU etc)

however using throttle-stop in windows you MIGHT be able to overclock them

but theres no such util for OS X AFAIK
 
MP 3,1 can be overclocked in Mac OS using the ZDNet tool. Don't quite remember the restrictions on OS support. I think you have to be in 32-bit mode to run the tool, but can reboot into 64-bit and clock speed setting sticks until shutdown. Been a few years since I had a 3,1 to use it on.

https://www.zdnet.de/39192217/exclusive-zdnet-overclocking-tool-enhances-performance-of-mac-pro/

Download link: https://downloads.zdnet.de/3494/zdnet-clock-dep0qi/


This overclocks the FB-DIMMS as well, so need to watch for ECC errors in system log. I seem to recall running 440-465MHz FSB for a 10-16% OC.
 
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MP 3,1 can be overclocked in Mac OS using the ZDNet tool. Don't quite remember the restrictions on OS support. I think you have to be in 32-bit mode to run the tool, but can reboot into 64-bit and clock speed setting sticks until shutdown. Been a few years since I had a 3,1 to use it on.

https://www.zdnet.de/39192217/exclusive-zdnet-overclocking-tool-enhances-performance-of-mac-pro/

Download link: https://downloads.zdnet.de/3494/zdnet-clock-dep0qi/


This overclocks the FB-DIMMS as well, so need to watch for ECC errors in system log. I seem to recall running 440-465MHz FSB for a 10-16% OC.

aye yeah, that attacks the clock generator

where as throttle stop attacks the multiplier, which on a QX9775 is unlocked :)

sadly I dont think any such multiplier manipulation tool like throttle stop exists for OS X
 
Mac Pro don't have any overclock support and probably don't have the ID for QX9775, at least I never saw it.

Unless you can get it really cheap elsewhere, with the price of one QX9775 on eBay ($239,99), you probably can buy a basic MP4,1 if you search a little, the price of two will get you a nice MP5,1.

If someone were able to extract the ACPI aml file from the Mac Pro's boot rom, we could edit the Speedstep table to allow for Overclocking via the multiplier and also change the voltage core.

ReggieSE can also to this manually, but I don't think it works after 10.6.

Not really worth all the trouble for a 3,1, given compatible Extreme CPU's are so pricey, but it can be done.
 
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tbh im still waiting for someone to try inject 1067A Microcode into a MacPro3,1 BootROM to see if 1067A aka E0 stepping CPUs then work :)

(I have a good feeling the MacPro3,1 does not work with E0 stepping CPUs because of the bug the E0 stepping has where when no microcode is loaded, it causes a bunch of CPU instruction sets go "missing", and I wonder if the Mac Pro firmware needs one of these to POST)
 
tbh im still waiting for someone to try inject 1067A Microcode into a MacPro3,1 BootROM to see if 1067A aka E0 stepping CPUs then work :)

(I have a good feeling the MacPro3,1 does not work with E0 stepping CPUs because of the bug the E0 stepping has where when no microcode is loaded, it causes a bunch of CPU instruction sets go "missing", and I wonder if the Mac Pro firmware needs one of these to POST)
That would be great if someone could do that. I don't even know where to begin with that sort of thing. And unfortunately no one really cares about 3,1s anymore aside from a select few...
 
That would be great if someone could do that. I don't even know where to begin with that sort of thing. And unfortunately no one really cares about 3,1s anymore aside from a select few...

id do it myself, but sadly I dont have a MacPro3,1 (or an Xserve2,1 for that matter)

however if someones willing to experiment with their MacPro3,1 im fully up for helping them :)
 
id do it myself, but sadly I dont have a MacPro3,1 (or an Xserve2,1 for that matter)

however if someones willing to experiment with their MacPro3,1 im fully up for helping them :)
You need to keep in mind that MP3,1 don't have matt cards and uses FWB flash memory in the TSOP-32 package, unbricking it is practically impossible without lab equipment and lots of practice. It's very easy to lift a pad and difficult to align the used FWB memory in the TSOP socket to reprogram it.

I personally bricked 3 MP3,1 boards and only got one reprogrammed/resoldered successfully, after that I stopped all research with MP3,1.
 
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You need to keep in mind that MP3,1 don't have matt cards and uses FWB flash memory in the TSOP-32 package, unbricking it is practically impossible without lab equipment and lots of practice. It's very easy to lift a pad and difficult to align the used FWB memory in the TSOP socket to reprogram it.

I personally bricked 3 MP3,1 boards and only got one reprogrammed/resoldered successfully, after that I stopped all research with MP3,1.

indeed, and its why Im hoping to get a MacPro3,1/Xserve2,1 myself personally so no one ends up with a dead machine if things go wrong, however if anyone does a MacPro3,1 there willing to experiment with then im all ears :)

but imagine how I felt when I was doing the first experiments with my MacPro2,1 and Xserve1,1 :)

before there where nice GUI tools to change Microcodes about and I had to do it all manually in a hex editor!

ahh fun times LOL https://forums.macrumors.com/threads/updating-a-mac-pro-s-cpu-microcode.2114187/
 
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