Hello fellow Haswell/Devil's Canyon overclockers!
I made posts
in various threads on this topic but have decided to make a thread to keep information and testing from getting buried.Summary:
The latest CPU microcode 22 (released in 2017) improves overclocking for Haswell over previous microcodes. I found this out accidentally, but have found the improvement over previous microcodes to be 100% reproducible, and another user has posted similar results. To update your BIOS' microcode and try for yourself, follow the simple steps in the spoiler below.
So far this has been replicated multiple times by myself
, several users on reddit
and users in this thread. Reported voltage reduction for a given clockspeed varies from 0.04 to 0.01v with an average of 0.02v, depending on CPU and initial overclock stability. For some this is enough to increase their clockspeed beyond what was possible before, for others it means running the same clocks at lower voltages and temperatures.
For me, I went from 4.7GHz to 4.8 at the same voltage of 1.3v, and got [email protected]
, a clockspeed that originally crashed with my motherboard BIOS' stock microcode 19 on starting a x264 stress test. I even found 5GHz to be within stable reach.Steps for updating microcode:
Warning: Spoiler! (Click to show)
Newest Haswell Microcode 23 (20/11/17)
: This involves flashing your motherboard with an edited BIOS. If you don't feel comfortable with this, don't attempt it. I take no responsibility for failed BIOS flashes.
This simple process is done through the UBU tool and instructions found in this guide: https://www.win-raid.com/t154f16-Tool-Guide-News-quot-UEFI-BIOS-Updater-quot-UBU.html
. Either use the extensive guide found on the thread, or use the guide below.
1. Download the latest UBU tool from the linked thread.
2. Download MMTool.exe and put it into the folder with the UBU.bat file. A copy can be found here under the link MMTool (aptio 5): http://voltground.com/haven/threads/13/
3. Acquire a copy of your BIOS from the manufacturer's product support site or otherwise.
4. Run UBU.bat and select your saved BIOS file. Once all the modules have loaded, navigate to the CPU microcode section by pressing 7 and enter.
5. Press 1 and enter to navigate to the list of microcodes, type 17 for the latest broadwell microcode (makes no difference what you choose for broadwell) then type 22 for the Intel microcode (19 says it's the best for overclocking, but my testing says otherwise).
6. Hit 0 to exit, then hit 1 to save it with a USB BIOS Flashback compatible name. If you don't have an ASUS board it will let you keep the original BIOS name or leave it as bios.bin to be renamed as necessary.
7. *Back up your BIOS settings/profiles before flashing!* Flash the updated BIOS with your preferred method. While some motherboards allow the edited BIOS to be flashed conventionally, ASUS users must use USB BIOS Flashback to get around safety checks. Check online to see how best to update your motherboard's BIOS.
If you have an ASUS board without USB BIOS Flashback, the only known working method to flash your BIOS is with an SPI programmer (£4 on amazon) following this guide
You could also try updating your microcode in software and bypass the need to edit your BIOS, detailed below.
- worse OC potential than with 22 but protects against spectre hack:Warning: Spoiler! (Click to show)
Update microcode through software for Intel systems after sandy bridge
Killkernel found and tested an even newer microcode, 23 dated 20/11/2017 that is not currently included in the UBU package. His testing found greater improvements over 22, check out his post
for instructions on where to find it. You can use the newer microcode by specifying the file through the UBU menu (make sure there are no spaces in the filepath leading to your microcode file, or in other words, put the microcode file on the desktop and go from there).
So far I have found overclocking with 23 to be on-par or possibly a little worse
than with 22, with no additional headroom.LostParticle
observed a clear regression in overclocking headroom with microcode 23 over the previous 22.
- Needs more testing!:Warning: Spoiler! (Click to show)
Motherboards reported as successfully flashed
If BIOS flashing doesn't work for your board, try updating your microcode through windows instead. It will load the updated microcode at kernel load, so just as your computer starts to load into windows from the BIOS. It will override the BIOS' microcode so long as the BIOS' microcode version is older. It works with any SkyLake, Kaby Lake, Haswell, Ivybridge or Xeon equivalent motherboard/cpu running windows, but has not yet shown overclocking improvements in testing.In my own testing
I so far have not found software updated microcode to offer overclocking improvements as updated BIOS microcode does.
A one-click tool to do this can be found here
, along with links to guides to do it without the tool.
Thanks to THEBOSS619 for the incredibly easy to use updating tool.
(this serves as a general guide - similar motherboards will most likely work too):
Warning: Spoiler! (Click to show)
ASRock Z87 Extreme6
ASRock Z97 Extreme4
ASRock Z97 OC Formula
ASUS Maximus Hero Z87
ASUS Maximus VII ImpactAW17 R1/Ranger/R5
EVGA Z97 Classified
MSI Z97 MPOWER MAX AC
MSI Z87-GD65 Gaming
MSI Z97 Gaming 5
MSI Z97 G45 Gaming
I haven’t seen this microcode talked of anywhere else. I suspect it's because people lost interest in testing Haswell microcode by 2017 when 22 was released. In particular, this seems to be the reason why microcode 19 is stated to be the best for overclocking in the UBU tool, as not enough testing occurred to show 22's improvements. Good luck and happy overclocking!