iMac slow suddenly. Three question marks (???) next to RAM

Tempoheart

macrumors newbie
Original poster
Mar 3, 2017
7
0
SoCal
Hi everyone!
I have a pretty strange situation and hoping someone can help before I cry (LOL jk)
For the past few days I have been transferring files from all my external drives (I have 4) and placing them on a new 5TB External HD for a backup.

I checked on the iMac this morning and everything was working great with all files transferred. All of a sudden when I opened Chrome to go to a website, the iMac gave me the rolling beach ball and eventually wouldn't load the webpage. I went to close Chrome and it took at least 30 secs to close.
After that, everything that I go to open is taking at least 1 minute or more to open. I disconnected all external HDs, restarted several times, unplugged from wall to no avail.
I've tried looking at system preferences to see if the fan was not working but it took too long to open.

Heres the thing: I have 20GB of RAM in my iMac. It has been really fast until now.
I was able to finally open "About this Mac" and next to the memory it says "20 GB ???". I don't know what the three question marks mean and have never seen it before.

I was able to click "system report" and all RAM says "OK" next to it. I'm really confused why all of a sudden this is happening. And of course, while I'm in the middle of a huge project

Anyone that can help?? :-/
 

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casperes1996

macrumors 603
Jan 26, 2014
5,022
2,926
Horsens, Denmark
Hi everyone!
I have a pretty strange situation and hoping someone can help before I cry (LOL jk)
For the past few days I have been transferring files from all my external drives (I have 4) and placing them on a new 5TB External HD for a backup.

I checked on the iMac this morning and everything was working great with all files transferred. All of a sudden when I opened Chrome to go to a website, the iMac gave me the rolling beach ball and eventually wouldn't load the webpage. I went to close Chrome and it took at least 30 secs to close.
After that, everything that I go to open is taking at least 1 minute or more to open. I disconnected all external HDs, restarted several times, unplugged from wall to no avail.
I've tried looking at system preferences to see if the fan was not working but it took too long to open.

Heres the thing: I have 20GB of RAM in my iMac. It has been really fast until now.
I was able to finally open "About this Mac" and next to the memory it says "20 GB ???". I don't know what the three question marks mean and have never seen it before.

I was able to click "system report" and all RAM says "OK" next to it. I'm really confused why all of a sudden this is happening. And of course, while I'm in the middle of a huge project

Anyone that can help?? :-/
Never seen it before either, but here are three suggestions (and one half suggestion that is always mentioned though I don't think it'll affect this situation, though it might still)

1) Run the extended hardware test/diagnostics.
2) Keep a close eye on Activity Monitor and see how it treats your resources - i.e. does it use the RAM, go to swap, is the CPU running at high load and so on.
3) Reboot into single user mode and run fsck -fy

4) SMC and NVRAM resetting
 

Tempoheart

macrumors newbie
Original poster
Mar 3, 2017
7
0
SoCal
Thanks Casperes, I'll give those 4 things a try. I left it over night to see if it would hopefully restore itself but that didn't work. I'll try the things you said.
 

kohlson

macrumors 68020
Apr 23, 2010
2,356
696
If it worked before and doesn't now, I would try reseating the RAM. Depending on the environment (humidity/vibration) they may not be making optimal contact. And the hardware/diagnostics cited above should highlight if this is the case, and/or the RAM has become defective.
 

Tempoheart

macrumors newbie
Original poster
Mar 3, 2017
7
0
SoCal
Hmm I'm not sure if the RAM has become defective because I'm able to see it under system report and status says "OK" but I also notice it saying ECC disabled. Not really sure what that means. I'm About to run diagnostics hope I can find a solution.
 

kschendel

macrumors 65816
Dec 9, 2014
1,061
334
I think the ??? is where the memory speed and type would normally display. I don't know why it would turn into ?'s though. "ECC disabled" is normal, as far as I know ECC is only supported on the Xeon's. I agree with the poster who suggested re-seating the RAM - should be easy to do and might solve the problem.
 

DeltaMac

macrumors G4
Jul 30, 2003
10,338
2,736
Delaware
"ECC: Disabled" is normal when you don't have ECC memory sticks installed. The iMac doesn't support ECC anyway, so the notice is simply informational.

Have you tried the Diagnostics test? (Reboot, while holding the "D" key)
 

Tempoheart

macrumors newbie
Original poster
Mar 3, 2017
7
0
SoCal
I just tried Diagnostics by holding down the D key but when it would finally boot it would just take me to the login portion. It never opened Diagnostics :-/
When reseting RAM is this something you do internally within the system or do you physically taking out the RAM and reinstalling?
 

Tempoheart

macrumors newbie
Original poster
Mar 3, 2017
7
0
SoCal
Just Re-installed RAM and was a little faster loading osx but then started lagging again.
I finally got diagnostics to run and I'm running the extended test so we'll see what comes up.
 

Tempoheart

macrumors newbie
Original poster
Mar 3, 2017
7
0
SoCal
The diagnostics test finished. I ran both the extended and standard and they both said "no trouble found"
Wouldn't it detect if a certain ram module was failed?
It wouldn't be the video card right? I actually had that replaced about 2 years ago because I found that the iMac's from mid-2011 had faulty cards so apple replaced them for free. I wouldn't think it would have failed so early though.
 

casperes1996

macrumors 603
Jan 26, 2014
5,022
2,926
Horsens, Denmark
It wouldn't be the video card right? I actually had that replaced about 2 years ago because I found that the iMac's from mid-2011 had faulty cards so apple replaced them for free. I wouldn't think it would have failed so early though.
This isn't a failure with the GPU. The behaviour you describe in no way is similar to GPU failures.

The diagnostics should in theory tell if a RAM stick had problems, yes. – Did you try reseating the RAM as suggested?
With further consideration, it sounds like the SPD profile of the sticks isn't being reported to the system. I.e. it's not telling the Mac at what speed it can run the memory at, so OS X/macOS runs the RAM at the lowest possible speed
 

Fishrrman

macrumors Core
Feb 20, 2009
19,609
6,825
Do you still have the factory-original RAM?
If so, remove any 3rd-party DIMMs and "go back" to the factory configuration.
Any changes afterwards?
 

kschendel

macrumors 65816
Dec 9, 2014
1,061
334
Presumably you have 4 + 16 in there? try running with just one of the sticks and see what happens.
 

Tempoheart

macrumors newbie
Original poster
Mar 3, 2017
7
0
SoCal
Hey guys. So I tried reseating RAM and that didn't work. I thought maybe one of them (or all) had come loose or something but I think I figured it out and this is going to sound really weird:
I turned on the Mac this morning and wanted to see if programs were going to run after letting it sit over night. I turn it on, log in and the popup asking if I want to open whatever windows were open before shutting off and I clicked "cancel" this time. It opens faster than usual with no programs opening. I click on system preferences, activity monitor and just try a few things and they seem fine. I opened Logic and Final cut and run them at the same time and they both were working fine. Looked at the activity monitor and it wasn't very taxing on the cpu. I had no idea why it was working now.
THEN I clicked on Chrome browser, that I have used for years and it freezes everything again. I shut the mac off, turn it on again. Go to open Safari and then firefox then other programs and it was fine. I open Chrome and it freezes.
My only guess is that Chrome was still set to automatic updates, it updated and had a bug or that the Chrome files had somehow gotten corrupt. It still makes no sense to me but I deleted Chrome and it seems to be running smoothly. I wonder if anyone else is having that problem. I am using Mavericks still so maybe when it updated the new version has a conflict with the older OSX.
But I think it might be fixed for now. I still think it's weird about the "???" that came up next to the RAM size.
Thanks guys for all your help and all the advice because I actually did learn a lot in this post that I didnt know how to do before. I wonder if anyone else has had this problem with Chrome since it updated. It just seems weird that one program would cause everything else to freak out. hmm
Thanks again!!
 

cynics

macrumors G4
Jan 8, 2012
11,586
1,884
When I've had hardware strangeness reseting the NVRAM has fixed it (or the SMC reset I do at the same time). May have already done it but nothing to really lose if not IMO.
 

casperes1996

macrumors 603
Jan 26, 2014
5,022
2,926
Horsens, Denmark
Thanks guys for all your help and all the advice because I actually did learn a lot in this post that I didnt know how to do before. I wonder if anyone else has had this problem with Chrome since it updated. It just seems weird that one program would cause everything else to freak out. hmm
Well, it could have a memory leak that could cause something like that, but that should get resolved when you quit the app, so I really don't know.

(Memory leak being where a program hogs up memory and never lets it go, taking up more and more and never freeing it again)
 

dfelix

macrumors member
Jul 13, 2011
96
102
Do a check/repair disk on your boot drive. You can only do this in the preboot environment.
 
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