Boot external ssd

Question

Boot external ssd

Hi I was wondering whether someone could help me out with this or comment whether it’s even possible…

So I’ve got a late 2015 iMac with a 1TB internal SATA drive and 8GB of memory, both of which are officially not upgradable. As my iMac takes quite a long time to boot (maybe like 7min don’t think it should be that way LoL) I was thinking that perhaps changing the boot drive to an external SSD would speed things up a bit. The only thing is I’ve decided to experiment and try boot camp on the internal drive and to my surprise Windows 10 runs better than Monterrey with all the latest updates.

So basically I’m asking whether it’s possible to have the storage on the internal SATA drive as extra space for my Mac and share that drive with a bootcamp/windows partition, while booting exclusively off the external SSD drive, and how I would go about doing that.

Thanks.

iMac (2017 – 2020)

Posted on Jul 11, 2023 11:16 AM

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Answer 1

Jul 11, 2023 1:20 PM in response to RaggedNuggetBandit

just to add to ku4hx's reply, please see Use an external SSD as your startup disk with your iMac or Mac mini - User Tip to implement that.

and FYI, I too have a Samsung T7 SSD for that purpose. but I use mine to run Catalina because of a piece of hardware that the vendor ended support for any macOS after Catalina.

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Answer 2

ku4hx

Level 7

23,694 points

Jul 11, 2023 12:24 PM in response to RaggedNuggetBandit

My late 2015 iMac 21.5" ran beautifully from an external SSD. Went from about 90 MBps read speed on the internal HDD to 450-480 MBps read speed with the external Samsung T7 SSD

I chose to erase the internal drive ands use it strictly for storage. Worked flawlessly for about 8 months when I replaced the internal HDD with an SSD.

Bootcamp I have no experience with. I use VMWare Fusion for running Windows and Linux.

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Answer 3

Jul 22, 2023 6:43 PM in response to RaggedNuggetBandit

FYI, most likely the internal hard drive is failing. macOS happens to be installed to a section of the drive currently with the bad sectors. Windows is probably using a part of the drive which does not currently have bad sectors. You can try checking the health of the internal hard drive by using DriveDx (macOS), or by using GSmartControl (Windows...portable version available so no install necessary) and posting the complete text health report here using the "Additional Text" icon which looks like a piece of paper.

Or maybe macOS has a software issue which is causing the performance issue. Maybe try booting into Safe Mode to see if it performs any better. If it does, then you may just have an issue with some third party software. Usual culprits are anti-virus apps, cleaning/optimizer apps, or third party security software.....none of which are needed on a Mac.

You can try running the Apple Diagnostics to see if any hardware issues are detected. Unfortunately most drive failures are not detected by the diagnostics....the two drive health monitoring apps I mentioned are able to identify the majority of hard drive failures.

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Answer 4

Jul 27, 2023 7:01 PM in response to RaggedNuggetBandit

If you are sure you have all your data on your external boot drive and also on one or more backup drives, then you can erase the internal drive while booted to your new external drive. Just make sure you have copies of any important data first.

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Answer 5

Jul 21, 2023 4:43 PM in response to RaggedNuggetBandit

Hi guys. Sounds great. I´m going to install Monterrey to my external SSD (150GB Kingston) and use it as my boot drive. The thing is I already have bootcamp on the internal drive set up as boot. ONce I install the OS on the SSD and use it as the boot drive, the Bootcamp install on the internal drive will no longer work (I think it has to be set up on the boot drive), or perhaps not:

https://eshop.macsales.com/blog/40947-tech-tip-how-to-use-boot-camp-on-an-external-drive/

A 240GB SSD doesnt sound like a lot of space to share with Windows. I guess I can eliminate the bootcamp install on the internal SATA drive and just leave it as extra storage, hopefully.

Thanks!

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Answer 6

Jul 27, 2023 4:24 AM in response to HWTech

Well, now I've got Monterrey installed on the external ssd drive, but now I've got two sets of Apps, LIbrary, Users, etc folders: one on the internal SATA and one on the external ssd drive. Which folders can I delete or use as-is on the internal SATA drive and which should I keep? Thanks.

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Boot external ssd

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