Imac painfully slow after installing Sierra OS

[halbitton]

Hi guys,
I have a late 2009 imac 27" i5 chip 4gb ram 1TB HD that came originally with snow leopard. When support for that OS ceased, I installed Sierra 10.12.6. Ever since, my machine has been extremely slow, and seems clogged with spam and adware. Do I need more RAM?, do I need to install a later OS?, is there something else I can do?, is this a known issue? Any help would be greatly appreciated. Thanks and best regards, Hal

 

[Dopeyman]

1. Did you do a clean install or did you just "update"?
- I would recommend a clean install

2. Remove the 1TB HD and install an SSD

 

[curmudgeonette]

4gb ram ... Do I need more RAM?

Yes!

 

[nambuccaheadsau]

And after that the SSD. Give your iMac a new lease of life.

 

[Fishrrman]

OP wrote:
"Do I need more RAM?, do I need to install a later OS?, is there something else I can do?, is this a known issue?"

Adding RAM probably won't help much, or at all. Could be a waste of money.

There's ONE THING that is slowing the iMac down:
THE PLATTER-BASED HARD DRIVE.

Modern OS's run like molasses on platter-based hard drives.
They need SSD's, or at the very minimum, a "fusion" drive.

Your options:
1. Open the iMac and install an SSD (can be a tricky job, things can get broken if you're not careful).
2. Add an EXTERNAL USB3 SSD. You have only USB2, so the boot times won't be faster, but once up-and-running it will help somewhat.
3. Look for a newer Mac.

Since a 2009 iMac is now approaching 9 years old, I'd say that "door number three" is your best choice...

(Then again, you could always "go back" to the previous OS install you had that [I assume] was running OK...)

 

[h9826790]

2. Add an EXTERNAL USB3 SSD. You have only USB2, so the boot times won't be faster, but once up-and-running it will help somewhat.

Actually, the boot time, apps loading time, overall system responsiveness will be much better even with just USB 2.0. I tried that myself. The boot time just few more seconds than internal SATA connection. For sequential read / write, USB 2.0 is a huge bottleneck, but boot time is not that bad. OP can still greatly benefit from the SSD's high IOPS.

 

[nambuccaheadsau]

It don't have no USB3 fisho being a 2009.

Bite the bullet and toss an SSD in it., Suggest avoiding a Samsung EVO model as they do not play nice with pre 2010 Macs, not completely backwards compabible. Posted a linjk on another thread about this from ifixit.

 

[chscag]

3. Look for a newer Mac.

This. You can "juice" up that old horse, but it's still an old horse.

 

[Krayzkat]

Upgrading to SSD will certainly increase your speed, but if you have only just upgrade the OS in last week or so then your computer might be going through all your saved photos etc and archiving them under key words etc.

I know when i upgraded my 2010 iMac from the OS immediately before Sierra, to High Sierra, if took about a week for the 'archiving' and very slow processing speed to finish. After that was done, everything was fine. I moaned on this forum at the time, especially about not even having a warning telling me what would happen.