macOS 13 Ventura on Unsupported Macs Thread

[PicklesDominic]

What version of OCLP? What brand model internal SSD have installed?

In OCLP application, select Settings > Build > General, and check Show Open Core Boot Picker and bump up Boot Picker Timeout to 20. I do this to give me time to review the disk choices. Handy if you have different boot disks available. To boot Open Core Ventura, pick the Ventura disk or wait for timeout if Ventura disk the default. In Debug section, check Verbose. This will show logging output during boot. Make sure you have selected the correct Target Host model before you Build and Install Open Core to your Ventura boot disk.

OPCL is version 2.4.1, SSD is Western Digital (CT500P2SSD8 in system information) of sorts I believe, 500GB dual booted with Windows 10.

I have the timeout set at 0 so it just goes straight into booting Ventura. No issues getting to the apple logo and loading bar, just takes forever to get to the login screen.

Correct target host model.

Verbose doesn't seem to get hung up on anything, or have any faillures. Its just slow to boot.

 

[Bigwaff]

Try disable File Vault.

 

[PicklesDominic]

Try disable File Vault.

Already disabled ):

 

[DeltaMac]

Your CT500P2SSD8 is a Crucial brand drive, not Western Digital.
You have a Crucial P2 - unfortunately not much of a speed demon.
And, I would hesitate to suggest swapping out that P2, just for more speed. New PCIe drives have all had huge price hikes recently.

 

[PicklesDominic]

Your CT500P2SSD8 is a Crucial brand drive, not Western Digital.
You have a Crucial P2 - unfortunately not much of a speed demon.
And, I would hesitate to suggest swapping out that P2, just for more speed. New PCIe drives have all had huge price hikes recently.

Ah that's right, forgot about Crutial. This drive has always been fairly speedy, not sure what you mean by not muchof a speed demon lol. Has fairly good read/write speeds given its an older drive on an older computer.

 

[DeltaMac]

Crucial swapped the P2's flash memory firmware during production, noticeably slowing the P2 down.
some more info about that here.

 

[NotABlindiSheep]

Hi all, I upgraded/updated my Late 2013 15" MBP from Big Sur 11.7.11 to Ventura 13.7.8 via OCLP version 2.4.1 last night (which turned into a very late night). Specs:

• 2.3 GHz Core i7
• 16 GB
• 512 GB SSD (350 GB MacOS partition & 150 GB Bootcamp partition)
• nVidia GT 750M

The post-install process was frustrating with EFI/USB-Free boot and boot picker screen issues so I'm explaining things here in case it helps anyone and I still have a couple of lingering issues I need to fix (if anyone can help that'd be great).

Pre-Install: I went through the documentation on Github and watched a few videos to understand the process (I never seem to have luck when tinkering with computers so wanted to make sure I knew what I was doing).

Installation: The install process went alright. Unexpectedly when the MBP restarted a few times during install it showed a boot picker screen like in this video (watch closely as the video is sped up). I didn't touch it at all when this occurred and the installation eventually finished on its own. I didn't encounter the issue where the loading bar stops at 40% due to driver problems with the GT 750M (I read online before installation that people had this issue).

Post-install problems:

1. EFI/USB-Free boot issues: When the OCLP prompt appeared asking if I'd like to not boot via USB (why would anyone not want that as default?) I clicked Yes/OK and installed OCLP to my internal SSD and disk0s1 EFI. The problem is this didn't work. During reboot I held the Option key and no "EFI Boot" (with SSD symbol) appeared, only the "EFI Boot" (with external disk symbol) appeared. At that point I still had my USB plugged in, the videos I watched didn't say when to unmount the USB and the documentation here doesn't advise to unmount USB before restarting.

I troubleshot the problem and read that supposedly the EFI Boot install can stuff up, so I created a new 200 MB MS-DOS (FAT16) partition (for some reason there was no FAT32 option) on my MacOS partition and built-and-installed OCLP again via the prompt, this time selecting the 200 MB FAT16 partition instead of the disk0s1 EFI. This allowed me to boot without the USB drive. A problem that occurred here is a 16.8 MB "Microsoft Reserved" partition disappeared when I created the FAT16 partition, I didn't delete it.

TL;DR Couldn't boot without USB, needed to create 200 MB FAT16 partition to install OCLP EFI onto.

2. Boot picker screen issues: I restarted a few times to ensure I didn't need the USB to boot but realised the boot picker screen appeared every restart which was annoying. Advice online said to uncheck the "Show OpenCore Boot Picker" setting in OCLP and then "Build and Install OpenCore" which I did (again, onto internal SSD and FAT16 partition), but for some reason the MBP booted into Windows by default instead of MacOS. Even when I restarted and held Option and selected "EFI Boot" (the icon with the SSD symbol) it weirdly booted into Windows (WTF!). I could not boot into MacOS at all, no option worked (MacOS SSD would show the 🚫 symbol). So I shutdown, booted into Ventura using the USB EFI again then went to sleep because it was really late, regretting that I cared that much about bypassing the boot picker screen.

Today I got back to it and deleted the 200 MB FAT16 partition and re-created it, then built-and-installed OCLP -- again to the internal SSD and FAT16 partition to try and fix the issue. I tried this a few times to no avail. Then I realised maybe the issue was that I didn't re-tick the "Show OpenCore Boot Picker" option when building, so after creating a fresh 200 MB FAT16 partition I ticked that option, built-and-installed OCLP to it and I was finally able to boot without USB again (but the boot picker screen came back, as expected).

TL;DR After unchecking "Show OpenCoreBoot Picker" in OCLP settings then build-and-installing to SSD and FAT16 partition, MBP boots into Bootcamp by default. Even holding Option and selecting EFI Boot (with SSD symbol) it boots into Windows. Needed USB to boot and rechecked "Show OpenCore Boot Picker" then built-and-installed to SSD and fresh FAT16 partition again. Can boot into Ventura but boot picker screen still appears.

Lingering issues:

1. The first "diskutil list" I ran after upgrading showed a 16.8 MB "Microsoft Reserved" disk0s3 on my disk0 (internal, physical). When I created the first 200 MB FAT16 partition this disappeared, I absolutely did not willingly delete it. I need to figure out how critical this was. I can still boot into Windows when I select it during startup.

2. I still dislike the boot picker screen appearing so want to fix it but I'm scared I'll have to go through the "Boot picker screen issues" process again if something messes up. I don't know why the EFI Boot (with SSD symbol) option booted into Windows instead of MacOS, that was really strange.

 

[Bigwaff]

During reboot I held the Option key

That the Mac native boot picker screen. From there, select your supported macOS disk or Windows or… select your OCLP EFI disk and you will see OC boot picker. Select your unsupported macOS disk. It has always worked this way when holding Option while booting.

 

[NotABlindiSheep]

That the Mac native boot picker screen. From there, select your supported macOS disk or Windows or… select your OCLP EFI disk and you will see OC boot picker. Select your unsupported macOS disk. It has always worked this way when holding Option while booting.

Thanks for the reply!

That's what I did but there was no OCLP EFI disk/SSD option (i.e. an OpenCore logo with SSD icon titled "EFI Boot/Boot EFI"). There was only MacOS, Windows and the USB EFI option. I don't think OCLP installed the EFI onto my internal SSD properly, that's why I had to create a 200 MB FAT16 partition and install the OCLP EFI onto it.

Only then did the OCLP EFI disk/SSD option appear, but again when I went to uncheck "Show OpenCore Boot Picker" and built and installed OCLP to my internal SSD and 200 MB partition (to stop the boot picker screen appearing every restart) it stuffed up and the OCLP EFI disk/SSD option booted into Windows by default instead (and this happened if I manually selected the OCLP EFI disk/SSD option or let it boot without selecting an option), so I had to USB boot and essentially create a new EFI partition again. Bloody frustrating, maybe it was because I upgraded from Big Sur instead of doing a clean install.

 

[Daniel Pascoal]

I never ever had to create EFI partion, it's always there after system install. It's a special partition that will not show on Disk Utilily, only through diskutil list.

It's possible that you created an additional regular FAT partition, and put OCLP there, while Windows boot was at the correct EFI. I don't know, check with diskutil.

One tip, hold Option for the offical Apple bootpicker, and hold ESC for OCLP Boot Picker to show. This way you can uncheck the "Show OpenCore Boot Picker". While at OCLP boot picker presse Space to see all options.

 

[Daniel Pascoal]

Hi all, I upgraded/updated my Late 2013 15" MBP from Big Sur 11.7.11 to Ventura 13.7.8 via OCLP version 2.4.1 last night (which turned into a very late night).

I was on Ventura on my mid 2012 15" MBP, but since Ventura is receinving security updates anymore I moved to Sonoma and some how it feels faster. Give it a try.

Your Mac can easly run Sequoia too.

 

[OKonnel]

Hi all, I upgraded/updated my Late 2013 15" MBP from Big Sur 11.7.11 to Ventura 13.7.8 via OCLP version 2.4.1 last night (which turned into a very late night). Specs:

• 2.3 GHz Core i7
• 16 GB
• 512 GB SSD (350 GB MacOS partition & 150 GB Bootcamp partition)
• nVidia GT 750M

The post-install process was frustrating with EFI/USB-Free boot and boot picker screen issues so I'm explaining things here in case it helps anyone and I still have a couple of lingering issues I need to fix (if anyone can help that'd be great).

Pre-Install: I went through the documentation on Github and watched a few videos to understand the process (I never seem to have luck when tinkering with computers so wanted to make sure I knew what I was doing).

Installation: The install process went alright. Unexpectedly when the MBP restarted a few times during install it showed a boot picker screen like in this video (watch closely as the video is sped up). I didn't touch it at all when this occurred and the installation eventually finished on its own. I didn't encounter the issue where the loading bar stops at 40% due to driver problems with the GT 750M (I read online before installation that people had this issue).

Post-install problems:

1. EFI/USB-Free boot issues: When the OCLP prompt appeared asking if I'd like to not boot via USB (why would anyone not want that as default?) I clicked Yes/OK and installed OCLP to my internal SSD and disk0s1 EFI. The problem is this didn't work. During reboot I held the Option key and no "EFI Boot" (with SSD symbol) appeared, only the "EFI Boot" (with external disk symbol) appeared. At that point I still had my USB plugged in, the videos I watched didn't say when to unmount the USB and the documentation here doesn't advise to unmount USB before restarting.

I troubleshot the problem and read that supposedly the EFI Boot install can stuff up, so I created a new 200 MB MS-DOS (FAT16) partition (for some reason there was no FAT32 option) on my MacOS partition and built-and-installed OCLP again via the prompt, this time selecting the 200 MB FAT16 partition instead of the disk0s1 EFI. This allowed me to boot without the USB drive. A problem that occurred here is a 16.8 MB "Microsoft Reserved" partition disappeared when I created the FAT16 partition, I didn't delete it.

TL;DR Couldn't boot without USB, needed to create 200 MB FAT16 partition to install OCLP EFI onto.

2. Boot picker screen issues: I restarted a few times to ensure I didn't need the USB to boot but realised the boot picker screen appeared every restart which was annoying. Advice online said to uncheck the "Show OpenCore Boot Picker" setting in OCLP and then "Build and Install OpenCore" which I did (again, onto internal SSD and FAT16 partition), but for some reason the MBP booted into Windows by default instead of MacOS. Even when I restarted and held Option and selected "EFI Boot" (the icon with the SSD symbol) it weirdly booted into Windows (WTF!). I could not boot into MacOS at all, no option worked (MacOS SSD would show the 🚫 symbol). So I shutdown, booted into Ventura using the USB EFI again then went to sleep because it was really late, regretting that I cared that much about bypassing the boot picker screen.

Today I got back to it and deleted the 200 MB FAT16 partition and re-created it, then built-and-installed OCLP -- again to the internal SSD and FAT16 partition to try and fix the issue. I tried this a few times to no avail. Then I realised maybe the issue was that I didn't re-tick the "Show OpenCore Boot Picker" option when building, so after creating a fresh 200 MB FAT16 partition I ticked that option, built-and-installed OCLP to it and I was finally able to boot without USB again (but the boot picker screen came back, as expected).

TL;DR After unchecking "Show OpenCoreBoot Picker" in OCLP settings then build-and-installing to SSD and FAT16 partition, MBP boots into Bootcamp by default. Even holding Option and selecting EFI Boot (with SSD symbol) it boots into Windows. Needed USB to boot and rechecked "Show OpenCore Boot Picker" then built-and-installed to SSD and fresh FAT16 partition again. Can boot into Ventura but boot picker screen still appears.

Lingering issues:

1. The first "diskutil list" I ran after upgrading showed a 16.8 MB "Microsoft Reserved" disk0s3 on my disk0 (internal, physical). When I created the first 200 MB FAT16 partition this disappeared, I absolutely did not willingly delete it. I need to figure out how critical this was. I can still boot into Windows when I select it during startup.

2. I still dislike the boot picker screen appearing so want to fix it but I'm scared I'll have to go through the "Boot picker screen issues" process again if something messes up. I don't know why the EFI Boot (with SSD symbol) option booted into Windows instead of MacOS, that was really strange.

Hi!
Why go through all that trouble with Ventura? Your Mac with OCLP works perfectly with Sonoma.
Ventura was almost a "transitional" system (like Big Sur), while Sonoma has reached a level of stability similar to that achieved by Monterey after Big Sur.
My late-2013 iMac with an nVidia graphics card works perfectly with Sonoma. Even resource-intensive apps all run very smoothly.
If I were you, I’d avoid Sequoia, because compared to Sonoma, it was a step backward for me. After six months with Sequoia, I went back to Sonoma because I’d had enough of all those little bugs, glitches, and instability.
The only downside is that, since Apple keeps updating Sonoma under the guise of security, starting with version 14.8.3 of Sonoma Apple has completely banned the use of Apple Compressor (as you can see online), while in version 14.4 of Sonoma Safari introduced significant changes to WebGL that prevent certain maps from loading on websites and other limitations. (for example, check out the post office search on Poste.it).
If I could do it easily, then, I’d go back to Sonoma 14.3.1 and stop updating it.
As for security, I discovered Avira, which is fantastic even in the free version and, once activated, detects threats on both web pages and in emails.

 

[Daniel Pascoal]

Hi!
Why go through all that trouble with Ventura? Your Mac with OCLP works perfectly with Sonoma.
Ventura was almost a "transitional" system (like Big Sur), while Sonoma has reached a level of stability similar to that achieved by Monterey after Big Sur.
My late-2013 iMac with an nVidia graphics card works perfectly with Sonoma. Even resource-intensive apps all run very smoothly.
If I were you, I’d avoid Sequoia, because compared to Sonoma, it was a step backward for me. After six months with Sequoia, I went back to Sonoma because I’d had enough of all those little bugs, glitches, and instability.
The only downside is that, since Apple keeps updating Sonoma under the guise of security, starting with version 14.8.3 of Sonoma Apple has completely banned the use of Apple Compressor (as you can see online), while in version 14.4 of Sonoma Safari introduced significant changes to WebGL that prevent certain maps from loading on websites and other limitations. (for example, check out the post office search on Poste.it).
If I could do it easily, then, I’d go back to Sonoma 14.3.1 and stop updating it.
As for security, I discovered Avira, which is fantastic even in the free version and, once activated, detects threats on both web pages and in emails.

Completely agree with Sonoma being a better choice than Ventura and Sequoia on these 2012-2013 Macs with nVidia graphics. Sequoia had lots of glitches and stability issues on my 2012 MBP too. From what I could gather the glitches only happens with Macs using nVidia.

Tested the poste.it map with Safari 26.4 and is really not opening. But it works fine with Firefox. Eventually Safari and Chrome will stop getting updates on Sonoma, but Firefox will continue for a very long time, it always does, it's the best option for older OSes. Still up to date on Catalina! And even has Extended Support Releases for older MacOses.

It's pretty easy to go back to Sonoma 14.3.1, here's the installer: https://archive.org/details/mac-os-sonoma-14.3.1-install-assistant

 

[OKonnel]

Completely agree with Sonoma being a better choice than Ventura and Sequoia on these 2012-2013 Macs with nVidia graphics. Sequoia had lots of glitches and stability issues on my 2012 MBP too. From what I could gather the glitches only happens with Macs using nVidia.

Tested the poste.it map with Safari 26.4 and is really not opening. But it works fine with Firefox. Eventually Safari and Chrome will stop getting updates on Sonoma, but Firefox will continue for a very long time, it always does, it's the best option for older OSes. Still up to date on Catalina! And even has Extended Support Releases for older MacOses.

It's pretty easy to go back to Sonoma 14.3.1, here's the installer: https://archive.org/details/mac-os-sonoma-14.3.1-install-assistant

That’s so kind of you! Thanks! I’ve already reverted to version 14.3.1, both because I’ve been a Mac expert for nearly thirty years (including using Terminal… ;-) and because this time (humility never hurts…) I followed Google AI’s step-by-step instructions to resolve the issues with the Photos library as well, and even though I synced with iCloud (in addition to finding a March 2024 library in Time Machine), I discovered that when launching Photos, instead of to press only Enter or clicking with the mouse, it’s better also to hold down CMD+Option to repair the database, which will then integrate with Spotlight.
I’m finding that the system has returned to a much more stable and responsive state. Apple, in fact, now assumes that everyone has the lightning-fast Apple Silicon chips and therefore feels free to load the latest versions with security measures that only slow down our Macs and cause minor issues in the background.
The AI also explained to me what happened starting with 14.4 and why Apple blocked Compressor starting with 14.8.4.
So, it fully agreed with my decision as soon as I clarified that I am a very experienced user and, above all, that I USE OCLP! In fact, it complimented me on my decision, which it finds absolutely perfect and the most ideal for my Mac

 

[NotABlindiSheep]

I never ever had to create EFI partion, it's always there after system install. It's a special partition that will not show on Disk Utilily, only through diskutil list.

It's possible that you created an additional regular FAT partition, and put OCLP there, while Windows boot was at the correct EFI. I don't know, check with diskutil.

One tip, hold Option for the offical Apple bootpicker, and hold ESC for OCLP Boot Picker to show. This way you can uncheck the "Show OpenCore Boot Picker". While at OCLP boot picker presse Space to see all options.

Yes from all the guides I saw, after the first boot into the upgraded OS OCLP asks if you want to boot without USB then you follow the instructions but it didn't work for me; the OCLP prompt kept coming up after I had built and installed OCLP to the disk and internal EFI which is why I had to make a FAT16 partition and install the EFI on there. The internal SSD's EFI did show up when I ran "diskutil list" in Terminal but it didn't show up in Disk Utility.

I will give your tip a shot the next time I reboot, thanks!

I was on Ventura on my mid 2012 15" MBP, but since Ventura is receinving security updates anymore I moved to Sonoma and some how it feels faster. Give it a try.

Your Mac can easly run Sequoia too.

Hi!
Why go through all that trouble with Ventura? Your Mac with OCLP works perfectly with Sonoma.
Ventura was almost a "transitional" system (like Big Sur), while Sonoma has reached a level of stability similar to that achieved by Monterey after Big Sur.
My late-2013 iMac with an nVidia graphics card works perfectly with Sonoma. Even resource-intensive apps all run very smoothly.
If I were you, I’d avoid Sequoia, because compared to Sonoma, it was a step backward for me. After six months with Sequoia, I went back to Sonoma because I’d had enough of all those little bugs, glitches, and instability.
The only downside is that, since Apple keeps updating Sonoma under the guise of security, starting with version 14.8.3 of Sonoma Apple has completely banned the use of Apple Compressor (as you can see online), while in version 14.4 of Sonoma Safari introduced significant changes to WebGL that prevent certain maps from loading on websites and other limitations. (for example, check out the post office search on Poste.it).
If I could do it easily, then, I’d go back to Sonoma 14.3.1 and stop updating it.
As for security, I discovered Avira, which is fantastic even in the free version and, once activated, detects threats on both web pages and in emails.

I did consider going to Sonoma but I was concerned there would be issues with the system slowing down. I had no idea Ventura was a "transitional system", I thought each MacOS update was quite large. Ventura is the MacOS I need for some software to run so I figured I would just go with that for now.

Thanks for the information though, maybe in a year's or few month's time I'll consider upgrading to Sonoma via OCLP. I'm guessing that upgrading from a non-supported MacOS to another non-supported MacOS via OCLP is the same process as a first-time OCLP upgrade?

 

[OKonnel]

Yes from all the guides I saw, after the first boot into the upgraded OS OCLP asks if you want to boot without USB then you follow the instructions but it didn't work for me; the OCLP prompt kept coming up after I had built and installed OCLP to the disk and internal EFI which is why I had to make a FAT16 partition and install the EFI on there. The internal SSD's EFI did show up when I ran "diskutil list" in Terminal but it didn't show up in Disk Utility.

I will give your tip a shot the next time I reboot, thanks!


I did consider going to Sonoma but I was concerned there would be issues with the system slowing down. I had no idea Ventura was a "transitional system", I thought each MacOS update was quite large. Ventura is the MacOS I need for some software to run so I figured I would just go with that for now.

Thanks for the information though, maybe in a year's or few month's time I'll consider upgrading to Sonoma via OCLP. I'm guessing that upgrading from a non-supported MacOS to another non-supported MacOS via OCLP is the same process as a first-time OCLP upgrade?

Hi! Better fix this before someone jumps all over me 🤣
It’s just my opinion that Ventura is a transitional system, based on my observations…
I’ve been using Macs for over thirty years, and I’ve realized that while all the various systems are complete, there are still some that are more mature and remain benchmarks.
For example, Mac OS X 10.4 Tiger was a huge leap forward compared to Puma, Jaguar, and Panther. Then came Snow Leopard. And so on.
Since macOS 11 was released, however, Monterey has been a mainstay, followed by Sonoma, which OCLP developers were in fact able to get up and running very quickly on Macs with Metal from 2013 onward.
Sequoia started to become problematic because Apple’s security measures became more aggressive. The
The drives connected to my late-2013 iMac, for example, made constant noise, or the fans kicked in frequently. Then there were minor bugs and annoying lag. Finally, Preview and AirPlay to Mac weren’t working well, and so on.
So after six months on Sequoia, in March 2025 I switched back to Sonoma, which I then immediately updated from 14.4 to 14.8.4.
At this point, a few days ago, tired of discovering that many things no longer worked (with 14.8.3, Apple added a blacklist that blocks Compressor and who knows what else…), I went back to 14.3.1, and my Mac is once again incredibly quiet and running in a way and with a smoothness I had forgotten.

 

[Peter Franks]

Would anyone know why I can't ever log in without seeing this now, OCLP Ventura on old 2011 MBP 13"

Bit annoying. Nothing is running when it's shut down. But.... every time I'm greeted with this
The main hog of my CPU is WindowServer and kernel task.

EDIT:
For the record, I've tried 'Cancel' and 'Open' when it starts up, but it always remains, every time, every day it's switched on.

 

[alphascorp]

Would anyone know why I can't ever log in without seeing this now, OCLP Ventura on old 2011 MBP 13"

Bit annoying. Nothing is running when it's shut down. But.... every time I'm greeted with this
The main hog of my CPU is WindowServer and kernel task.

EDIT:
For the record, I've tried 'Cancel' and 'Open' when it starts up, but it always remains, every time, every day it's switched on.

View attachment 2619215

Hi @Peter Franks

Maybe there are "Sleep Wake Failure" log files in /Library/Logs/DiagnosticReports/
Delete them to solve your issue.

Or running the excellent (free) Onyx utility should also resolve your issue.

Please note that there is a different version for each macOS; look in the “Old Versions” section to find the version that matches your OS. Development of older versions of OnyX has been discontinued, however you can still download them.

Edited : typo

 

[RK78]

Re. Onyx, I'm running Firefox 140.9esr on my Ventura, which can be very slow and buggy. What would be your suggestion for what exactly to run on Onyx, if that might do any good to resolve Firefox issue?

 

[alphascorp]

Re. Onyx, I'm running Firefox 140.9esr on my Ventura, which can be very slow and buggy. What would be your suggestion for what exactly to run on Onyx, if that might do any good to resolve Firefox issue?

Hi @RK78
The Onyx utility allows you to clear system caches. However, it does not directly target third-party browser caches like Chrome or Firefox in the same way as a dedicated cleaner. His action is more global on the system.

To speed-up Firefox, have you tried to clear the cache.
Click the menu button (at the top right) to open the menu panel.
Click History and select Clear Recent History…
Next to When: choose Everything from the drop-down menu, select Temporary cached files and pages in the items list, make sure other items you want to keep are not selected.
Then click the Clear button.

Have you also tried to start Firefox in a safe mode (which disables all of your add-ons) by holding down the option key while clicking on the icon to launch Firefox. If Firefox is faster in safe mode, If Firefox is faster in safe mode, one or more add-ons are likely the cause.

To exit safe mode, simply exit and restart Firefox.

 

[RK78]

Hi @RK78
The Onyx utility allows you to clear system caches. However, it does not directly target third-party browser caches like Chrome or Firefox in the same way as a dedicated cleaner. His action is more global on the system.

To speed-up Firefox, have you tried to clear the cache.
Click the menu button (at the top right) to open the menu panel.
Click History and select Clear Recent History…
Next to When: choose Everything from the drop-down menu, select Temporary cached files and pages in the items list, make sure other items you want to keep are not selected.
Then click the Clear button.

Have you also tried to start Firefox in a safe mode (which disables all of your add-ons) by holding down the option key while clicking on the icon to launch Firefox. If Firefox is faster in safe mode, If Firefox is faster in safe mode, one or more add-ons are likely the cause.

To exit safe mode, simply exit and restart Firefox.

Thanks for all that. Actually, have tried all that before, but one thing I never tried, which I just noticed occurs in Safe Mode, is the JIT Compiler is disabled. Which can be done manually after exiting Safe Mode by setting to false from true the following in about:config:

javascript.options.baselinejit
javascript.options.ion
javascript.options.asmjs

Surprisingly counter intuitive, since running the JIT Compiler disabled (as in Just In Time) should slow things down, but at least my initial impression, after running like that for a few minutes, is that FF (140.9esr) appears to be running faster. May not last, but will see how it goes for a while like that. Other than that, seem like something basic running FF in OCLP - why I thought that perhaps something in Onyx might help.

Although, kind of wary of running it in OCLP, especially anything system related, as it might inadvertently reverse something needed in OCLP?

 

[alphascorp]

Thanks for all that. Actually, have tried all that before, but one thing I never tried, which I just noticed occurs in Safe Mode, is the JIT Compiler is disabled. Which can be done manually after exiting Safe Mode by setting to false from true the following in about:config:

javascript.options.baselinejit
javascript.options.ion
javascript.options.asmjs

Surprisingly counter intuitive, since running the JIT Compiler disabled (as in Just In Time) should slow things down, but at least my initial impression, after running like that for a few minutes, is that FF (140.9esr) appears to be running faster. May not last, but will see how it goes for a while like that. Other than that, seem like something basic running FF in OCLP - why I thought that perhaps something in Onyx might help.

Although, kind of wary of running it in OCLP, especially anything system related, as it might inadvertently reverse something needed in OCLP?

Hi @RK78
In order to speed up javascript in Firefox, I changed the following two settings in about:config

javascript.options.baselinejit.threshold —> 50
javascript.options.ion.threshold —> 5000

This GitHub page is interesting to read to speed up Firefox: https://gist.github.com/RubenKelevra/fd66c2f856d703260ecdf0379c4f59db

Furthermore, the two above changes are in the middle of this page.

Edit:

This GitHub page is useful for disabling data collection and telemetry, which can also help prevent Firefox from slowing down: https://github.com/K3V1991/Disable-Firefox-Telemetry-and-Data-Collection

About Onyx:
I used Ventura for over two years, from January 2023 to November 2025, with OCLP (versions 0.6.1 through 2.4.1). After installing each update, I ran Onyx, and I never encountered any issues; on the contrary, the system actually ran faster afterward.
I've been using Sequoia with OCLP 2.4.1 since November 2025, and I continue to run Onyx after every update...

 

[RK78]

Many thanks for all that, even though my head is spinning from trying so many different options and combinations of options (can deal with that), especially the RubenKelevra linked. Good thing that I save the various profiles tried as alias to Desktop, which allows me to quickly revert. Might actually have hit on something now that works best.

Re. Onyx, which you say is safe to use in OCLP. Can you say just what you ran in Onyx? Maintenance, cleaning etc? (Btw, my supported OS is High Sierra on this iMc 10,1. Had been running Onyx there over the years, but never as yet in Ventura OCLP.)

 

[alphascorp]

Many thanks for all that, even though my head is spinning from trying so many different options and combinations of options (can deal with that), especially the RubenKelevra linked. Good thing that I save the various profiles tried as alias to Desktop, which allows me to quickly revert. Might actually have hit on something now that works best.

Re. Onyx, which you say is safe to use in OCLP. Can you say just what you ran in Onyx? Maintenance, cleaning etc? (Btw, my supported OS is High Sierra on this iMc 10,1. Had been running Onyx there over the years, but never as yet in Ventura OCLP.)

With Onyx, I only use the maintenance section with the default settings selected.

 

[RK78]

With Onyx, I only use the maintenance section with the default settings selected.

Really appreciate all the help and suggestions you’ve offered. Think it’s running far better now - fingers crossed it stays that way.