iM 4,1-14,4 iMac 2011 (see more) UEFI Firmware Mod

[JohnPascololo]

Happy to share the results of my christmas holiday iMac 12,2 modding session with @m0bil 's peace of tremendously cool work.

Having the native bootpicker and the ability to boot windows without further problems and opencore is really cool!

Geekbench 5 Results (with RAM frequency set to 1600MHz)

Unpatched boost multiplier

x40 boost multiplier

x44 boost multiplier

3D Mark Time Spy (all results with RAM frequency set to 1600MHz)

Unpatched Firmware & GPU Bios

No firmware patch & GPU Memory Frequency Clock set to 1750MHz and slightly increased power limit

Firmware patch with multiplier x40 & GPU Memory Frequency Clock set to 1750MHz and slightly increased power limit

Firmware patch with multiplier x44 & GPU Memory Frequency Clock set to 1750MHz and slightly increased power limit

oops, forgot to take a screenshot...

 

[ChrizLoud]

Tanks for posting results John!
Have you tried to go over x44 Boost Multiplier?
It would be fun to know the limits of the iMac cooling system.

 

[Maggehagge]

Aquired new iMac 2011 mpcb.. This time I used the leveler. 2700k is in. Compared to my other iMac 2011 with 2600s temps are actually the same besides 2600s iMac needs to ramp up fans to about 1100 rpm instead of 940 rpm keeping 82C on intel power gadget all threads load test. Now time for some overclocking magic

Edit: After some thinking this might be the 2600s original 13 year old thermal paste vs 2 hours old Arctic MX-4
Let's see what this Apple CPU cooling unit can do when overclocking.

a bit lower on the temps would be healthy. try increasing rpm slightly

 

[ChrizLoud]

Im talking about 82 degrees package temp (shown in Intel power gadget).
It seems that this is around here it peaks under full load in the Multithread test. It will not go higher with stock multiplier.

It also looks like the iMacs SMC wants it to be at 82c if it goes over this it will start to ramp up the fans (as seen on my 2600s thats needs a slightly higher cpu rpm to keep it at 82c). Since this behavior is stock and my 2600s is 12 years old now and always been on auto-fan setting im sure this will not be a problem.

When overclocking it will probably still try to keep it at 82c but i guess the cpu fan will ramp up more to keep it cool.

I will report back when i have more time for testing

 

[Maggehagge]

Apple is notorius for trading a single decibel for like having 10c hotter components.

 

[ChrizLoud]

I totally understand what you mean. The CPU cooling system impresses me in the 2011 iMac. Just to try it out what it can do in comparison to 930rpm 82c under full load, i raised the fan speed to 2600rpm (strange that my other iMac 2011 only can do 2100rpm with MacFans Control) temperature dropped to 57c under same test in Intel Power Gadget

 

[ChrizLoud]

Ive read out the bios with GRML but i can not find it on the USB? Please help me

Edit: Found it. Run the command saving it to the persistence folder = now i can see it in MacOS

 

[JohnPascololo]

@ChrizLoud I haven't tried higher multipliers but would be interested in your findings. For some reason I cannot program the BIOS from macOS. I had to use a programmer. I'm a little concerned about the total power draw when overclocking too much...

 

[ChrizLoud]

Total power draw? You mean the cpu voltage? I do not know if the voltage is on auto or not but CPU-Z under Windows will show it

 

[ChrizLoud]

Ok, first try with the patch set to patch standard 40 Multiplier. Its starts throttling down to 3.9ghz already at 65c and 3.8ghz at 72c? Is something wrong with the patch?

 

[ChrizLoud]

Update: x50 does not boot, windows, mac os or Linux

 

[ChrizLoud]

x48 no MAC OS boot BSOD in windows and no boot in Linux

 

[ChrizLoud]

x46 boots and seems stable.

x47 Put the Clip upside down.. No more LED on the mother board when clip is connected. Did i kill the programmer, the chip or the whole mother board..

Edit: Computer boots halfway into Mac OS before freezing so i guess BIOS chip is ok and i fried the programmer.

Second Edit: Ordered a new programmer from China. Please wait 2-4 weeks for x47 results...

Third Edit: I can actually boot Mac OS Ventura in Safe Mode on x48 . Since my programmer died, is it possible to flash bios from Mac OS?

 

[ChrizLoud]

Since it only boots in Mac OS and Safe Mode, is there any way i can write the bios from mac os?

 

[m0bil]

Since it only boots in Mac OS and Safe Mode, is there any way i can write the bios from mac os?

Did you apply eeprom flash protection removal patch?? If so, you can software flash the firmware, otherwise a hardware programmer is required.
If in a hurry, usually you can buy a ch341a in Amazon for a slightly higher price

 

[ChrizLoud]

Yes the eprom flash protection removal patch is applyed and i used the USB GRML Flashrom USB Stick to flash several times. Is it possible to run it from Mac OS since it will not boot anything else than Mac OS in Safe Mode?

No not really in a hurry But testing is fun

 

[m0bil]

Yes the eprom flash protection removal patch is applyed and i used the USB GRML Flashrom USB Stick to flash several times. Is it possible to run it from Mac OS since it will not boot anything else than Mac OS in Safe Mode?

No not really in a hurry But testing is fun

Good. While flashing from macOS is possible, you'll need to install the flashrom package using homebrew, I'm not sure your current config is stable enough to do that.

I think your best bet could be flashing from UEFI shell, no need to boot an OS. Try to create an OCLP/Opencore usb and boot from it, when the OCLP bootpicker shows press space to see if you can enter UEFI shell. If it works I'll give instructions on how to flash from there.

 

[ChrizLoud]

Thanks. Yes, Uefi Shell seems to boot ok.

 

[m0bil]

Thanks. Yes, Uefi Shell seems to boot ok.

ok, grab UEFI version of Intel Flash Programming Tool (FPT) from here, extract and copy both files along with the rom you want to flash to the root of some fat32 formatted usb drive (or even the OCLP/Opencore one), and navigate there from inside UEFI Shell. You should then be able to use fpt.efi command to read or write the firmware (I thing option /f for write and /d for read, speaking from memory...)

 

[ChrizLoud]

ok, grab UEFI version of Intel Flash Programming Tool (FPT) from here, extract and copy both files along with the rom you want to flash to the root of some fat32 formatted usb drive (or even the OCLP/Opencore one), and navigate there from inside UEFI Shell. You should then be able to use fpt.efi command to read or write the firmware (I thing option /f for write and /d for read, speaking from memory...)

Thanks! It flashed via UEFI Shell without problems.
Now running x47. It seems a bit unstable. Mac Os Freezes some times and windows gives Blue Screens.
I wonder what rasing the CPU Voltage can do?

Also it still throttles the CPU over 65c. Now running IPG Stress test Allt-threads at only 3.8 Ghz while 4.7 Ghz is requested.

Temperature stabile at 72c with CPU fan @1600 rpm-

 

[m0bil]

Thanks! It flashed via UEFI Shell without problems.
Now running x47. It seems a bit unstable. Mac Os Freezes some times and windows gives Blue Screens.
I wonder what rasing the CPU Voltage can do?

Also it still throttles the CPU over 65c. Now running IPG Stress test Allt-threads at only 3.8 Ghz while 4.7 Ghz is requested.

Temperature stabile at 72c with CPU fan @1600 rpm-

Nice! I won't consider it stable unless able to run some torture test like Prime95 for about an hour without issues. In my tests I got x45 stable but x46 sometimes freezes, anyway not all this second-hand CPUs behave the same.

Besides unlocking the Turbo overclock and setting the max multipliers, the patch does not change or limit any other power settings, I wonder if ACPI or some other OS power feature is responsible for throttling. Can you try ThrottleStop in Windows?, I think this overrides ACPI/Power settings and just lets CPU thermal throttle in place.

My lab iMac is broken right now (I killed the GPU), but I'll make an overvolting patch if you want to test (also I think in Throttlestop there is an overvolt setting, but I'm not sure if it works in Sandy Bridge - meaning you can change the value but I'm not sure if it takes effect).

 

[ChrizLoud]

Nice! I won't consider it stable unless able to run some torture test like Prime95 for about an hour without issues. In my tests I got x45 stable but x46 sometimes freezes, anyway not all this second-hand CPUs behave the same.

Besides unlocking the Turbo overclock and setting the max multipliers, the patch does not change or limit any other power settings, I wonder if ACPI or some other OS power feature is responsible for throttling. Can you try ThrottleStop in Windows?, I think this overrides ACPI/Power settings and just lets CPU thermal throttle in place.

My lab iMac is broken right now (I killed the GPU), but I'll make an overvolting patch if you want to test (also I think in Throttlestop there is an overvolt setting, but I'm not sure if it works in Sandy Bridge - meaning you can change the value but I'm not sure if it takes effect).

Overvolting was not possible in ThrottleStop. It is just dimmed out. I think 100% stable at 4.6-4.7 ghz should not be a problem with a over voltage patch but over that the iMac cooling system will probably not be able to keep the temps down. Im ready to try if you want to make one

 

[ChrizLoud]

4.6 Ghz Seems stable. No problems benchmarking or stress testing.
Here is my GeekbBench 5 results with 32 GB 1600mhz RAM.

 

[ChrizLoud]

If you compare this to my other stock iMac 2011 i7 2600 the upgrade is well worth it.

My father has an 2017 iMac i5 and my 2011 kicks its ass now

 

[JohnPascololo]

Little off topic, but maybe someone can help:

Since we have the native boot picker available now and the firmware plays nicely with windows thanks to the patches I would prefer to run Windows natively without opencore. Currently I have 3 options in the apple boot picker:

EFI Boot / Monterey / Windows 11

Since Monterey requires opencore it will not boot natively. Is there a known way to hide it from apples bootpicker? Also can i rename the open core entry called "EFI Boot" to Monterey?