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Mr. 123

macrumors 6502
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Sep 20, 2016
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Hello,
I have an iMac 27 inch from 2017. It's the 3,5 Ghz model with 40GBs of RAM and a 1TB SSD. I am running Mojave and the computer is very fast on that system. Does anyone have experience with Big Sur running on this computer?

I have often noticed how new systems generally slow down the computer, contributing to a lack of longevity, so would stay on Big Sur if there is a slowdown.

Any user experience would be helpful!
 
I'm running Big Sur 11.4 on my 2017 27" iMac 5K and have absolutely no problems with it. No slowdowns going from Mojave to Catalina and now to Big Sur.

Your mileage may be different however. Keep in mind that upgrading to Big Sur will kill off all your 32 bit apps that still run with Mojave.
 
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Hello,
I have an iMac 27 inch from 2017. It's the 3,5 Ghz model with 40GBs of RAM and a 1TB SSD. I am running Mojave and the computer is very fast on that system. Does anyone have experience with Big Sur running on this computer?

I have often noticed how new systems generally slow down the computer, contributing to a lack of longevity, so would stay on Big Sur if there is a slowdown.

Any user experience would be helpful!
Yeah it should run fine. I have this system (with the 3.8) and it doesn't really feel any different than any prior update.
 
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Thanks for the replies!

I might updating this year! I’ve been a bit weary about updating because of a huge slowdown happening with my old
MBP and Sierra but based on your replies it seems that Big Sur should be running well!

I do have a few 32 bit apps so would need to see if there are alternatives.

thanks!
 
Hello,
I have an iMac 27 inch from 2017. It's the 3,5 Ghz model with 40GBs of RAM and a 1TB SSD. I am running Mojave and the computer is very fast on that system. Does anyone have experience with Big Sur running on this computer?

I have often noticed how new systems generally slow down the computer, contributing to a lack of longevity, so would stay on Big Sur if there is a slowdown.

Any user experience would be helpful!

That iMac is beefy enough that you ought to not notice any performance slowdowns at all. I might advise a clean installation of Big Sur, rather than an upgrade, however.

Thanks for the replies!

I might updating this year! I’ve been a bit weary about updating because of a huge slowdown happening with my old
MBP and Sierra but based on your replies it seems that Big Sur should be running well!

I do have a few 32 bit apps so would need to see if there are alternatives.

thanks!

And, actually, given this, I'd probably recommend you either do a clean install Big Sur on a separate APFS container to run side-by-side with your existing Mojave installation. Or back up your Mojave installation, wipe your drive, create two APFS containers, one for Big Sur, one for Mojave, load all 64-bit Intel apps onto the Big Sur volume and reserve the Mojave installation solely for 32-bit apps that can't run in anything newer than Mojave. I'm doing this practice myself, albeit with two different Macs (rather than one Mac with a split volume).
 
That iMac is beefy enough that you ought to not notice any performance slowdowns at all. I might advise a clean installation of Big Sur, rather than an upgrade, however.
Sounds good as I bought this computer in 2018 for longevity and I plan on using it for many years!

Doing a clean install would be difficult as I have several apps that work on Catalina and Big Sur but whose installers do not so I’d need those apps pre installed from my current install. Would it work to do a clean install and then restore from a time machine backup? (I’m thinking that that would reinstall El Capitan though)
 
Big Sur 11.4 is just fine for me. In some cases I have the impression it's a bit faster.
2017 27" iMac (Retina 5K), 1TB SSD, 4.2GHz Quad-Core Intel Core I7, 16GB 2400MHz DDR4, Radeon Pro 575 w 4GB
 
Sounds good as I bought this computer in 2018 for longevity and I plan on using it for many years!

Doing a clean install would be difficult as I have several apps that work on Catalina and Big Sur but whose installers do not so I’d need those apps pre installed from my current install. Would it work to do a clean install and then restore from a time machine backup? (I’m thinking that that would reinstall El Capitan though)

FWIW my current install dates back to OS X 10.7.5 and has been upgraded through each beta release from 10.8 on. I’d make a backup, but you’ll probably be just fine upgrading from 10.14 to 11.0.
 
Sounds good as I bought this computer in 2018 for longevity and I plan on using it for many years!

Doing a clean install would be difficult as I have several apps that work on Catalina and Big Sur but whose installers do not so I’d need those apps pre installed from my current install. Would it work to do a clean install and then restore from a time machine backup? (I’m thinking that that would reinstall El Capitan though)
If you're running Mojave, create a brand new Time Machine back-up from that. Again, I'd probably just go the clean installation of both Mojave and Big Sur route and treat the apps that work in Catalina and Big Sur but can't install in those (likely due to a 32-bit installer, I'm guessing) as though they don't work in Catalina or Big Sur (which is to say, just have them installed on your Mojave partition). But, certainly, if your Mojave installation is otherwise running fine, you could leave it alone, make a Big Sur partition/container and then install it afresh. Hell, you could probably run the installer app from within Mojave and just target the partition/container you make for Big Sur. Easy Peasy.
 
FWIW my current install dates back to OS X 10.7.5 and has been upgraded through each beta release from 10.8 on. I’d make a backup, but you’ll probably be just fine upgrading from 10.14 to 11.0.
My install is from 2018 when I bough the computer. It came with High Sierra and then I installed to a late version of Mojave.
 
If you're running Mojave, create a brand new Time Machine back-up from that. Again, I'd probably just go the clean installation of both Mojave and Big Sur route and treat the apps that work in Catalina and Big Sur but can't install in those (likely due to a 32-bit installer, I'm guessing) as though they don't work in Catalina or Big Sur (which is to say, just have them installed on your Mojave partition). But, certainly, if your Mojave installation is otherwise running fine, you could leave it alone, make a Big Sur partition/container and then install it afresh. Hell, you could probably run the installer app from within Mojave and just target the partition/container you make for Big Sur. Easy Peasy.
I've never dealt with portions and multiple OS installs. Would I need to do some kind of switch / restart of the iMac to be able to use Adobe apps then (if they're installed on the Mojave partion?

I think there is a way to do a clean install and then bring over files via time machine or do you need to restore the whole system? Either way maybe wouldn't work with the pre installed adobe apps.
 
I've never dealt with portions and multiple OS installs. Would I need to do some kind of switch / restart of the iMac to be able to use Adobe apps then (if they're installed on the Mojave partion?

It's basically the same as using Boot Camp to boot Windows 10. The only difference is that you add the second container/partition in Disk Utility instead of the Boot Camp Assistant, and when you install your second operating system, you won't need drivers. You'll still use 'Startup Disk' to switch between which OS boots by default. This would become tedious if you were frequently going between apps that are on one OS versus another. But you could at least have the best of both worlds that way. Another option is to get either Parallels Desktop or VMware Fusion and create a virtual machine that is running your secondary macOS version. Though, only Big Sur has any 3D acceleration when running as a virtual machine. All of the earlier macOS releases don't have that support when run as a virtual machine.

I think there is a way to do a clean install and then bring over files via time machine or do you need to restore the whole system? Either way maybe wouldn't work with the pre installed adobe apps.
You absolutely can do it this way. In fact, this is Apple's preferred method, for the most part. However, I strongly recommend against doing this across different systems and/or versions of macOS. It quickly gets messier unless you're dealing with the exact same version of the OS on the exact same Mac (i.e. if you've just replaced your internal drive).
 
It's basically the same as using Boot Camp to boot Windows 10. The only difference is that you add the second container/partition in Disk Utility instead of the Boot Camp Assistant, and when you install your second operating system, you won't need drivers. You'll still use 'Startup Disk' to switch between which OS boots by default. This would become tedious if you were frequently going between apps that are on one OS versus another. But you could at least have the best of both worlds that way. Another option is to get either Parallels Desktop or VMware Fusion and create a virtual machine that is running your secondary macOS version. Though, only Big Sur has any 3D acceleration when running as a virtual machine. All of the earlier macOS releases don't have that support when run as a virtual machine.
Yes, this does sound a bit too complicated as I often use Adobe apps while listening to music in iTunes etc so I think Iäll stay with using only one OS.
You absolutely can do it this way. In fact, this is Apple's preferred method, for the most part. However, I strongly recommend against doing this across different systems and/or versions of macOS. It quickly gets messier unless you're dealing with the exact same version of the OS on the exact same Mac (i.e. if you've just replaced your internal drive).
Maybe I'll just install Big Sur over my existing Mojave install as I really need some of those pre installed apps with 32bit installers. I am also planning on using iTunes on Big Sur via Retroactive so updating might be more trouble than it's worth 😂
 
Yes, this does sound a bit too complicated as I often use Adobe apps while listening to music in iTunes etc so I think Iäll stay with using only one OS.

Here's where I'm confused. Adobe's apps are all 64-bit. "Music" is functionally identical to iTunes (as far as music collection and playback is concerned). You shouldn't need to stay behind on Mojave for that particular functionality. My suggestion was more predicated on the notion that you only have a few 32-bit only apps. 64-bit apps with 32-bit installers isn't that tricky to pull off, especially since you could likely install them onto the Big Sur system FROM the Mojave system. I'd still give it a go if you still need 32-bit support in your Mac life (but, I'd imagine that, as Mojave inches closer to total deprecation, these needs will go down over time).

Maybe I'll just install Big Sur over my existing Mojave install as I really need some of those pre installed apps with 32bit installers. I am also planning on using iTunes on Big Sur via Retroactive so updating might be more trouble than it's worth 😂
What's the need for iTunes in Big Sur? I'm not saying that I don't miss iTunes myself, but from a functional standpoint, the split-up of apps seems to cover all the bases. Again, you can probably run those installers on a Mojave system but targeting a Big Sur system. It depends on the installers being used though. Admittedly, I don't know what you're working with.
 
Here's where I'm confused. Adobe's apps are all 64-bit. "Music" is functionally identical to iTunes (as far as music collection and playback is concerned). You shouldn't need to stay behind on Mojave for that particular functionality. My suggestion was more predicated on the notion that you only have a few 32-bit only apps. 64-bit apps with 32-bit installers isn't that tricky to pull off, especially since you could likely install them onto the Big Sur system FROM the Mojave system. I'd still give it a go if you still need 32-bit support in your Mac life (but, I'd imagine that, as Mojave inches closer to total deprecation, these needs will go down over time).
Yes the Adobe apps all work on Big Sur, but just can't be installed (which wouldn't be a problem if I don't do a clean install of Big Sur). I have one 32bit app that I use but it's an audio converter (XLD) and there are decent alternatives to that like dBPoweramp. Running 32bit installers on a Mojave system is of course a possibility but I have never done that before.
What's the need for iTunes in Big Sur? I'm not saying that I don't miss iTunes myself, but from a functional standpoint, the split-up of apps seems to cover all the bases. Again, you can probably run those installers on a Mojave system but targeting a Big Sur system. It depends on the installers being used though. Admittedly, I don't know what you're working with.
The need for iTunes is because the new Music app isn't very stable and is still missing a lot of iTunes functionality. I am running Big Sur on my MacBook Air so I have used the music app there. But this shouldn't be much of an issue as you can use Retroactive to install iTunes on Big Sur without problems!
 
As well as considering the dual booting and making steps to do that, you could also look into seeing if a Mojave or High Sierra (or earlier) Virtual Machine would meet your needs for running 32-bit apps and if necessary upgrade the RAM in your machine so that you have enough RAM to do that and your existing workflow. The 27" 2017 iMac can take up to 64GB of RAM which is a lot more than the 40GB you currently have installed.

Some apps run better than others in a Virtual Machine so YMMV.

Edit: I see using a VM was already mentioned.
 
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As well as considering the dual booting and making steps to do that, you could also look into seeing if a Mojave or High Sierra (or earlier) Virtual Machine would meet your needs for running 32-bit apps and if necessary upgrade the RAM in your machine so that you have enough RAM to do that and your existing workflow. The 27" 2017 iMac can take up to 64GB of RAM which is a lot more than the 40GB you currently have installed.

Some apps run better than others in a Virtual Machine so YMMV.

Edit: I see using a VM was already mentioned.
Yes, considering that I only have one app that is actually 32bit, which can be replaced, I think I'll either install Big Sur over my current Mojave install or do a clean install and find a way of launching the 32bit installers and pointing the installs to Big Sur. I might also wait a bit and stay on Mojave for another couple of months before Monterey is released.
 
Yes the Adobe apps all work on Big Sur, but just can't be installed (which wouldn't be a problem if I don't do a clean install of Big Sur). I have one 32bit app that I use but it's an audio converter (XLD) and there are decent alternatives to that like dBPoweramp. Running 32bit installers on a Mojave system is of course a possibility but I have never done that before.

The need for iTunes is because the new Music app isn't very stable and is still missing a lot of iTunes functionality. I am running Big Sur on my MacBook Air so I have used the music app there. But this shouldn't be much of an issue as you can use Retroactive to install iTunes on Big Sur without problems!
So I had a couple of 32-bit apps that I essentially completely lost when I got this iMac (which already had Catalina installed on it). I'd been on High Sierra literally precisely for this reason, so my (2013) MacBook is my 32-bit machine. That said, I've personally moved on from Adobe (I refuse to subscribe to their software, and I *bought* CS6); but if you're unable to do that for your workflow, I'm honestly not sure what the upgrade would even provide. I only upgraded to Big Sur because I was already on Catalina.
 
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