activity monitor - something like it for top disk usage?

[pen-helm]

Activity monitor lets me see what apps are taxing the CPU, but under Disk I don't see anything exactly similar. Is there any way to see what apps are heavily using my various disks at a given moment?
(I realize it does provide some data.)

 

[MarkC426]

iStat menus, available on the App Store, or from the developer (with more features).

 

[pen-helm]

Thanks!

 

[MarkC426]

In addition, I don't think iStat menus tells you individual apps that are using disk....
You can see which drives are being accessed though.

 

[chabig]

under Disk I don't see anything exactly similar. Is there any way to see what apps are heavily using my various disks at a given moment?
(I realize it does provide some data.)

How do you think that information would be useful for anything? AM already shows bytes written and read. From that you can infer which apps use the disk and how much. But I am curious what you think the use is of that knowledge?

 

[pen-helm]

Actually it does!

 

[pen-helm]

How do you think that information would be useful for anything? AM already shows bytes written and read. From that you can infer which apps use the disk and how much. But I am curious what you think the use is of that knowledge?

My real question is, "why is my computer slow at the moment?" So I find it useful.

 

[MarkC426]

Post your specs, maybe we can help advise.

 

[pen-helm]

That's kind of you.

It's not slow all the time, just once in a while lately. It's an Intel iMac 5k, seven years old.
EtreCheck says:
I've got a runaway process (but I don't see anything in Activity Monitor.)
SSD is showing poor performance.
There are a large number of system modifications running the background.
This computer may be considered vintage.
There are external drives connected that could be affecting performance.

Memory: 16 GB (4.5 free.)
Disk: Software disk light is on most of the time. It has a Fusion drive, two Time Machine volumes attached (hard drives,) and three other hard drive volumes attached.
Internet: I get about 25 Mbps down.

Antivirus is SentinelOne, which doesn't seem to slow things down.

 

[MarkC426]

Upgrading to 32gb ram should make a difference.
Unfortunately as it's an iMac, there is not much else to upgrade (easily).

 

[howdytom]

@pen-helm It's the Fusion Drive, which slows things down! Fusion Drives getting slow at some point. Replacing the Fusion Drive with a SSD is difficult, though. You could talk to your your local dealer.

More info iMac Intel 27" Retina 5K Display Blade SSD Replacement

 

[pen-helm]

Thanks guys, I think you were both right. Although a big chunk of memory was free, nonetheless it was using several gig of virtual memory (to my surprise.)
And EtreCheck says the fusion drive is running slower than they usually do.

 

[InuNacho]

I wonder if something like TRIM ENABLER would help. I believe it works with Fusion Drives.

 

[pen-helm]

Good idea! But I think TRIM is already on, because it's an Apple drive.

 

[InuNacho]

I've often wondered how Apple manages TRIM on Fusion drives. I wanted to make one for my old Mac Pro when SSDs were a bit more costly. I suspect given all the issues people have had using Fusion Drives and OSes that they are not entirely managed by Apple's in house TRIM software.