iMac running of external SSD - freezing / slow boot / crashing

[WaffleMXM]

Hello everyone,
I’m running a Late 2015 27” iMac with 16GB of ram, i5-6500, R9 390m with a Fusion Drive and macOS Monterey.

The Fusion Drive has proven to be a bit problematic - it suffers loads of freezes and the read speed falls to below 1mbps.

I decided to get a Netac Z Slim usb SSD to run the iMac until I can save some money and do an inside upgrade(Nvme cpu ssd).

At first it was great, it worked like a charm - even though the boot was always weirdly long. Approx 2/5 mins at first.

After using it for some time - the boot time goes up to over 10 mins even 15 mins sometimes - which obviously is very problematic.

What makes this unbearable is that the computer does not wake from sleep. When I try to wake it up - the backlight goes on - no image - and then it crashes. Sometimes I get a message “your computer has been restarted because of an error” sometimes not.

I tried running commands to turn off hibernation and sleep hoping it would fix the issue - it didn’t.

I have been trying to find out more information about these issues but I couldn’t really find anyone experiencing similar issues to me.

At one point I thought maybe the ram was to blame ? But I run memtest86 on each of the ram sticks and no errors were found.

I would appreciate any help!

 

[DeltaMac]

You added the external drive because the internal drives (the fusion drive is two separate devices, seen by the system as a single storage drive) were causing problems.
I suspect that the fusion drive continues to disappoint. If you did not open the iMac to remove either device, they are still in place, and the hard drive, at least, would continue to spin, even though you may not use it at all. You may not get improvement until you remove the fusion drive devices. At this point, it will be challenging to determine which fusion drive device is the problem, although the spinning hard drive, being a mechanical drive, is the usual culprit, but you won't really know until you dig in to it a bit.

 

[WaffleMXM]

You added the external drive because the internal drives (the fusion drive is two separate devices, seen by the system as a single storage drive) were causing problems.
I suspect that the fusion drive continues to disappoint. If you did not open the iMac to remove either device, they are still in place, and the hard drive, at least, would continue to spin, even though you may not use it at all. You may not get improvement until you remove the fusion drive devices. At this point, it will be challenging to determine which fusion drive device is the problem, although the spinning hard drive, being a mechanical drive, is the usual culprit, but you won't really know until you dig in to it a bit.

I have Monterey on both the external SSD and internal Fusion Drive - the internal boots within 30 seconds. The external over 15 mins.
Id imagine if the internal was the issue it would go both ways?

 

[DeltaMac]

Did you get external and internal reversed in your last post? Thought you were having problems with the internal, and that you didn't use that now after going with the external.
So, long boots, even from the external... You would then want to try disconnecting the internal HDD, just as a test, to see if the external boot is faster without the internal drive. That is an issue, of course, because of the challenge to open the iMac just to disconnect the drive.
Have you tried "verbose boot", which can possibly tell you where in the boot process is lagging. Restart, holding Command-V. You will see text on the screen, showing you the progress of the boot, listing the name of each process that loads. You would be watching for individual processes that simply sit for an extended time (most simply flash by, in a normal boot.)
If you don't see anything of note - it might be worthwhile to try reinstalling your Monterey system. Reinstalling the system does not mean erasing and reinstalling all your apps.. Just a reload of the system software, which, as a result of the reinstall, can prune your system, and may correct problems that involve improperly installed system components, or even corrupted/damaged system files -- might help your issues that you are having with the slow boots.
How much space is free on that external drive, now?

 

[Nguyen Duc Hieu]

Hello everyone,
I’m running a Late 2015 27” iMac with 16GB of ram, i5-6500, R9 390m with a Fusion Drive and macOS Monterey.

The Fusion Drive has proven to be a bit problematic - it suffers loads of freezes and the read speed falls to below 1mbps.

I decided to get a Netac Z Slim usb SSD to run the iMac until I can save some money and do an inside upgrade(Nvme cpu ssd).

At first it was great, it worked like a charm - even though the boot was always weirdly long. Approx 2/5 mins at first.

After using it for some time - the boot time goes up to over 10 mins even 15 mins sometimes - which obviously is very problematic.

What makes this unbearable is that the computer does not wake from sleep. When I try to wake it up - the backlight goes on - no image - and then it crashes. Sometimes I get a message “your computer has been restarted because of an error” sometimes not.

I tried running commands to turn off hibernation and sleep hoping it would fix the issue - it didn’t.

I have been trying to find out more information about these issues but I couldn’t really find anyone experiencing similar issues to me.

At one point I thought maybe the ram was to blame ? But I run memtest86 on each of the ram sticks and no errors were found.

I would appreciate any help!

I guess your external nVME blade or the box (protocol controlling chip) has issues.
Detect the issue further by swapping:
- The box
- the nVME blade

Or save yourself a headache by ditching the Netac and use a well-branded SSD. I myself never use strange brand like Netac. Just stick to Samsung, SkHynix, Intel etc.

 

[WaffleMXM]

I guess your external nVME blade or the box (protocol controlling chip) has issues.
Detect the issue further by swapping:
- The box
- the nVME blade

Or save yourself a headache by ditching the Netac and use a well-branded SSD. I myself never use strange brand like Netac. Just stick to Samsung, SkHynix, Intel etc.

I was going to get a usb drive case and a ssd in the first place but then I saw a sale on amazon… I’ll go back to my original idea. I have an ssd in my old MacBook that I don’t use and a case.
I’m hoping that fixes the issues!

 

[Danhusker95]

I was going to get a usb drive case and a ssd in the first place but then I saw a sale on amazon… I’ll go back to my original idea. I have an ssd in my old MacBook that I don’t use and a case.
I’m hoping that fixes the issues!

hi! i've been having similar issues -2017 iMac with 16GB RAM and internal 1TB HDD which boots quickly but runs poorly. I have been booting from an external 500GB SSD which generally runs fine, but takes 5-10 minutes to boot, randomly won't wake from sleep (like you mentioned above) and frequently struggles to open apps or load. but when it works well, it works.

did you try your original method that you mention above? did it work better for you?

 

[Fishrrman]

danhusker wrote:
"I have been booting from an external 500GB SSD which generally runs fine, but takes 5-10 minutes to boot, randomly won't wake from sleep (like you mentioned above) and frequently struggles to open apps or load"

Pardon my temerity for asking, but are you SURE that you're actually booting from the external SSD and not from the internal HDD by accident?

Do you have the SSD set to be the boot drive (by using the startup disk preference pane)?

Other things I would check:
- try a different connecting cable
- if the SSD can be removed from the enclosure, try a different enclosure.

 

[Danhusker95]

Temerity fully welcomed.

I'm fairly positive I'm booting from the intended external SSD (see attached - Mac SSD is the bootable external).

The external SSD is an all-in-one drive/enclosure, it cannot be removed. So I'll have to go with a different cable. I'm using the one that came with the drive - USBC 3.1 to USBC (see package image attached).

Pardon my lack of knowledge on the subject, is it possible that:
1. I have the cable reversed? Would using one side into the SSD vs the other side have an impact?
2. Plugging into a lightning port on my iMac would be making things slower?
3. I should NOT use the USBC port for a bootable?

Thanks for all the guidance and patience!

 

[Fishrrman]

"I'm fairly positive I'm booting from the intended external SSD (see attached - Mac SSD is the bootable external)."

Hmmmm...
Just because it's listed as being bootable and external, doesn't mean that it's the drive that's actually being booted FROM.

Is the internal drive still bootable to the Mac OS, as well?

Do this:
Go up to the menu bar, click on the Apple, and choose "About this Mac".
It will tell you what the startup disk is.

Are the external SSD and the tm backup the only external drives that are connected?

 

[Danhusker95]

About this Mac indicates Mac SSD is the startup disk.

The internal drive is no longer bootable. I have it partitioned for Bootcamp, storage (as MacOS Journaled), as well as OSXReserved.

Other than that, the external SSD and the TM backup (also partitioned) are the only drives connected, yes.

HOWEVER - I just upgraded to the Samsung 980 with the OWC Envoy Enclosure as my bootable, and transferred everything from the tm. things (so far) are running SO MUCH better. 20 second boot time (which is fine for me, compared to the 15 minutes I was getting earlier). no lagging to open apps.

we'll see how things progress. but perhaps the 500 mb/s from the Gigastone drive wasn't sufficient for booting and daily use?

 

[Fishrrman]

Dan wrote:
"perhaps the 500 mb/s from the Gigastone drive wasn't sufficient for booting and daily use?"

I have a small 128gb SSD I use for experimenting with Ventura on my 2018 Mini.
It boots and runs just fine. I don't think that 500mb (size alone) was "the issue"... it was something else.

 

[Danhusker95]

Dan wrote:
"perhaps the 500 mb/s from the Gigastone drive wasn't sufficient for booting and daily use?"

I have a small 128gb SSD I use for experimenting with Ventura on my 2018 Mini.
It boots and runs just fine. I don't think that 500mb (size alone) was "the issue"... it was something else.

oh, i'm sorry. i meant that as the read/write speed. it's a 500GB drive. but yeah, who is to say. all i know is the NVMe is doing a lot better. i'm not gonna mess with anything for right now haha

thanks for your help!