Slow 2015 iMac 27" don't know what to try next

flyersgl

macrumors member
Original poster
Apr 3, 2009
73
0
South Jersey, USA
I have a mid 2015 27" iMac core i5 3.3 which I purchased in late 2015 as a refurb. Seems I didn't appreciate at the time that they'd reverted from a fusion drive to a traditional hard drive, and the machine was a bit laggy from the start. The main issue is internet - initial load of Safari can take 30 seconds or more for the first page to load. Reduces to 5-10 after that, but way slower than any other machine in the house. Other stuff has also increasingly started to beachball.

To date, I have done pretty much everything I know to do to speed internet without results. A speedtest says my download speed is 49Mps, which, while slower than the 72Mps my MBP is getting, it should be adequate.

And my 1TB hard drive is only about 2/3 full. Done usual diagnostics and small fixes on hard drive usage, but there doesn't seem to be an obvious issue there either.

Did I just get a lemon, and if so, what next?

I have not yet pursued a clean install/start over because there'd be a little bit of pain in letting some stuff that I have stuck in process in Lightroom go (I think). I'd be interested to hear if people think I should go there.

I get there is also the even more painful start over and install a SSD option, which I don't have time to take on on my own right now, so I'd have to pay some real money for that, again without knowing what comes from it.

It feels like trotting it into the apple store without an obvious, acute issue isn't going to get to any helpful solution, does that seem like the right conclusion?

Or, finally, do I cut my losses, get it into selling shape (being honest) and move on? Buy something that better meets my needs? That option is more painful after leaving my 2017 10.5" iPad Pro and Pencil on a plane this week.

I'd love to hear some thoughts.

Thank you
 

jerwin

macrumors 68020
Jun 13, 2015
2,455
4,448
An SSD might help a great deal.

(The closest I can come to an apples to apples comparison is my bootcamp installation, which became a lot more usable once I moved it to an external SSD. Admittedly, this may have been because the old installation lacked free space.)

however, iirc macosx does not support TRIM on USB SSDs.
 

alien3dx

macrumors 6502a
Feb 12, 2017
809
175
off spotlight,icloud sync.Sometimes, safari tend to memory leak which osx tend to compress memory till hang the computer.Cache is good but abusing is not.
 

Fishrrman

macrumors P6
Feb 20, 2009
17,160
5,520
"Seems I didn't appreciate at the time that they'd reverted from a fusion drive to a traditional hard drive, and the machine was a bit laggy from the start."

There's a quick, easy, cheap and SAFE way to speed things up:
Buy a USB3 SSD, plug it in, and set it up to be the boot drive.
Things will then run much MUCH faster.

Set up the SSD this way:
- Put the OS onto it
- Put apps on it
- Put "basic accounts"* onto it
- Keep it "lean and clean".

*By "basic accounts", I mean that you leave the "large libraries of stuff" (such as movies, music and photos) on the internal HDD. They don't need the speed of the SSD to run well. It's easy to "direct" your apps to look for those libraries on the internal drive, instead of the boot drive (the SSD).

DOING THE ABOVE IS NOT DIFFICULT.
You just have to get used to having two drives on the desktop to manage.
You'll know "where things are" in a very short time.

Again... fastest, easiest, cheapest -- and you don't have to pry the iMac apart.
Do this, and you'll come back here saying "I never believed it could run this FAST...."
 
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alien3dx

macrumors 6502a
Feb 12, 2017
809
175
"Seems I didn't appreciate at the time that they'd reverted from a fusion drive to a traditional hard drive, and the machine was a bit laggy from the start."

There's a quick, easy, cheap and SAFE way to speed things up:
Buy a USB3 SSD, plug it in, and set it up to be the boot drive.
Things will then run much MUCH faster.

Set up the SSD this way:
- Put the OS onto it
- Put apps on it
- Put "basic accounts"* onto it
- Keep it "lean and clean".

*By "basic accounts", I mean that you leave the "large libraries of stuff" (such as movies, music and photos) on the internal HDD. They don't need the speed of the SSD to run well. It's easy to "direct" your apps to look for those libraries on the internal drive, instead of the boot drive (the SSD).

DOING THE ABOVE IS NOT DIFFICULT.
You just have to get used to having two drives on the desktop to manage.
You'll know "where things are" in a very short time.

Again... fastest, easiest, cheapest -- and you don't have to pry the iMac apart.
Do this, and you'll come back here saying "I never believed it could run this FAST...."
mojave not user friendly with bootable disk..It freakin slow boot
 

nambuccaheadsau

macrumors 68000
Oct 19, 2007
1,739
409
Nambucca Heads Australia
If the operating system is cloned to the external USB3 SSD using SuoperDuper or CarbonCopyCloner of course it will boot in about 12-15 seconds. Mojave is fast and UI is first class. Best new OS since El Capitan but strongly recommend for SSDs only.
 
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flyersgl

macrumors member
Original poster
Apr 3, 2009
73
0
South Jersey, USA
Is it just Safari?
Thanks for replies so far. Safari is the main lag but most apps take a little bit to open. In playing around a little bit over the weekend, it really DOES seem like 80%+ of the issue is apps opening and a decent amount of the beach balling is when I get impatient waiting for one app to open and try to open another at the same time. Once in an application, things mostly work, though subsequent web pages opening still lags by a few seconds.

I did some clean up of hard drive and was contemplating installing Mojave, but the comment that "Mojave is meant for SSD" stopped me in my tracks. Is that true? I don't have it in me to do an internal hard drive replacement, but might go the USB3 external route. I presently have all my photos on an external USB3, so I am comfortable with the external solution.
 

jagolden

macrumors 65816
Feb 11, 2002
1,022
673
Have you installed the latest OS update? I Don’t mean Mojave but the one before that?
That previous update makes launching apps slow as molasses and the mail app is actually painful to use.
Yes, I’ll admit some of my apps are older (Adobe CS3, MS Office), but really?!
They were snappy previously.
Once they open they run OK, it’s just getting them to start.
 

ignatius345

macrumors 68020
Aug 20, 2015
2,321
3,078
Before you do all this hardware stuff, maybe a (fairly) quick diagnostic step to isolate and make sure this isn't something particular to something running in your user account:

Go into Preferences → Users & Groups and set up a new user. You have to authenticate, so click that lock icon lower left first, then the + button to add the new account.

iMac 2018-11-12 at 2.06.47 PM.png

Once that's done, restart the machine and log into that brand new account. To speed this all up, you can probably skip tying that new account to an Apple ID. Once you're logged in, see if Safari and other apps are still slow. If they aren't, it's something in your main user account that's going sideways.

If you want to delete that account, log out of it and back into your main account and from there select it and hit the minus button in Users & Groups. You also might want to just leave it, as it can be handy to have a "virgin" account around for troubleshooting purposes.
 

Fishrrman

macrumors P6
Feb 20, 2009
17,160
5,520
alien wrote in #6 above:
"mojave not user friendly with bootable disk..It freakin slow boot"

Nope.
I have a "test copy" of Mojave on an external USB3 SSD (which is formatted in HFS+).
It boots as fast as any other external SSD I have -- actually, a smidgeon faster.
[doublepost=1542125592][/doublepost]OP wrote:
"Mojave is meant for SSD" stopped me in my tracks. Is that true? I don't have it in me to do an internal hard drive replacement, but might go the USB3 external route.

I predict that if you take the advice I gave you in reply 4 above, you will be very happy.