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Sdahe

macrumors 68000
Original poster
Oct 26, 2007
1,723
23
San Juan, PR
Hello,

My 2017 Retina 5K iMac had 16gb (4x4gb sticks) and I took out 2x4gb memory sticks and replaced them with 2x16gb sticks for a total of 40gb of ram. I still feel the computer runs a bit slow. Is there something else I can do to make it work smoother?.. Im running MacOS Catalina 10.15.6 and the hard drive is SD.
 

G5isAlive

Contributor
Aug 28, 2003
2,724
4,675
What do you do that it feels slow to you? Just curious, agree with pldelisle that it might be the applications. very few applications actually need more than 16 gb ram so not terribly surprised that doesn't make a big change for you.

Do you have an external back up drive hooked up to it (you should)? I have a regular external for time machine and I notice that when it spins down that if I do anything file manipulation related that apple first spins up the external drive and that reliably slows down the interface for me.
 
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thekev

macrumors 604
Aug 5, 2010
7,005
3,343
Did you actually try to track down the bottleneck before purchasing it? More ram only helps if you're actually saturating what you already have. Generic advice is unlikely to help here, especially when you are not providing any relevant information. If your ui just seems laggy or something, it probably had nothing to do with your ram.

The hard drive is what ?

If it's a fusion drive, the problem is there.

If it's a SSD, it has no reason to feel slow. It might be software related.

Are fusion drives actually that bad on the latest versions of OSX or something? The op has plenty of ram, so they shouldn't be a problem, given that things will just end up cached in memory.
 

Sdahe

macrumors 68000
Original poster
Oct 26, 2007
1,723
23
San Juan, PR
What do you do that it feels slow to you? Just curious, agree with pldelisle that it might be the applications. very few applications actually need more than 16 gb ram so not terribly surprised that doesn't make a big change for you.

Do you have an external back up drive hooked up to it (you should)? I have a regular external for time machine and I notice that when it spins down that if I do anything file manipulation related that apple first spins up the external drive and that reliably slows down the interface for me.
I'm working files that are in an external HD connected through usb. Maybe that's why it feels slow when opening files
 

Sdahe

macrumors 68000
Original poster
Oct 26, 2007
1,723
23
San Juan, PR
Did you actually try to track down the bottleneck before purchasing it? More ram only helps if you're actually saturating what you already have. Generic advice is unlikely to help here, especially when you are not providing any relevant information. If your ui just seems laggy or something, it probably had nothing to do with your ram.



Are fusion drives actually that bad on the latest versions of OSX or something? The op has plenty of ram, so they shouldn't be a problem, given that things will just end up cached in memory.
I guess not because I don't know what the bottleneck is?.. don't know what you mean by that. What relevant information you'll need to give me advise?.. I'll look it up
 

Sdahe

macrumors 68000
Original poster
Oct 26, 2007
1,723
23
San Juan, PR
Pretty sure it's this. You are dependant of the USB bus. Hopefully it's UBS3.0 at least ......



Did you pay for the SSD upgrade or not ? Or go in System Report -> Storage. You'll know.
This is what I get under System Report -> Storage

Screen Shot 2020-09-09 at 4.40.46 PM.png
 

Nicole1980

macrumors 6502a
Mar 19, 2010
686
1,512
Hello,

My 2017 Retina 5K iMac had 16gb (4x4gb sticks) and I took out 2x4gb memory sticks and replaced them with 2x16gb sticks for a total of 40gb of ram. I still feel the computer runs a bit slow. Is there something else I can do to make it work smoother?.. Im running MacOS Catalina 10.15.6 and the hard drive is SD.

Ram is not going to noticeably 'speed up' your computer. Ram only matters if you generally do something that requires a lot of it and it's using all the ram you have. My guess is the programs you were using prior to the upgrade weren't really maxing out the ram, so going from 16 to 40 gigs would be virtually meaningless in that case.
 

thekev

macrumors 604
Aug 5, 2010
7,005
3,343
I guess not because I don't know what the bottleneck is?.. don't know what you mean by that. What relevant information you'll need to give me advise?.. I'll look it up

Well, you didn't mention what was lagging exactly. Is it ui elements and system animations? Do things load too slowly? Is it framerates in a game? Are you rendering videos that take too long? Being specific about what software is good. You didn't mention what you're using when you spot lag or if this is a constant issue.

Targeting the wrong thing just doesn't do much to improve your quality of life. I would generally suggest mentioning what OSX version you're running too, in case of known software issues. I don't know of any outstanding software issues at the moment that would cause lag.

This is what I get under System Report -> Storage

View attachment 951592

Even if you didn't have an SSD, reads are more frequent than writes. If you have excess memory, a lot of small frequently accessed stuff ends up cached in memory and you won't notice it outside of large reads anyway. I think people overstate the SSD issue sometimes.
 

profcutter

macrumors 65816
Mar 28, 2019
1,476
1,190
Sounds to me like the lag is the external drive. Try copying some work files from the external drive to the internal drive, and working on those files from there. Be sure to detach the external drive for this test, to be sure it’s out of the equation. If it speeds up, you know the external drive is the problem. “bottleneck” means that the system is only as fast as the slowest part you’re using, in this case, you have a very fast machine, but if it has to wait for the external hard drive to find a file and transfer it, that slows down the whole process, much like the neck of a bottle slows down liquid leaving the bottle when turned upside down. Remove the neck of the bottle, and the liquid all falls out at once.
 

G5isAlive

Contributor
Aug 28, 2003
2,724
4,675
I'm working files that are in an external HD connected through usb. Maybe that's why it feels slow when opening files

This is your problem. My passport drives are slow and frequently power down as they are usb powered. When you click on a file the drive has to wake up first. You can either live with it, or buy a faster external drive that is externally powered and doesn’t spin down, or a SSD external drive.
 
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BrianBaughn

macrumors G3
Feb 13, 2011
9,691
2,445
Baltimore, Maryland
An external SSD will shorten file access and transfer times.

There are several on the market or you can buy a USB 3 housing and bare SSD and put one together yourself.

Don't bother getting a more expensive USB 3.2 device…your iMac cannot take advantage of the maximum speed.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,588
12,697
OP:

Get a 1tb 2.5" "bare" SATA SSD.
I like Crucial and Sandisk -- they're not expensive.

Then, put it into an enclosure like this:
(it snaps right in, you don't even need tools)

Use disk utility to initialize (erase) it to HFS+ (Mac OS extended with journaling enabled, GUID partition format).

You could use either CarbonCopyCloner or SuperDuper to clone over the contents of the Passport drive to the new SSD.

I would then use the Passport drive for a backup for the INTERNAL SSD.
You might consider partitioning it 50/50.
Use the "first half" for the backup.
Use the other partition to backup your external for now.
Now... BOTH drives are backed up.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,588
12,697
"External HDDs and SSDs can run APFS".

Yes they can.
But they'll run BETTER with HFS+.
Particularly platter based drives, which suffer from terrible performance problems under APFS...
 

pldelisle

macrumors 68020
May 4, 2020
2,248
1,505
Montreal, Quebec, Canada
"External HDDs and SSDs can run APFS".

Yes they can.
But they'll run BETTER with HFS+.
Particularly platter based drives, which suffer from terrible performance problems under APFS...
True. APFS fit better with SSDs, but I haven't heard any problem with APFS for platter based HDDs. Fusion Drive have been running APFS for a couple of macOS versions and seems flawless.
 
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