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amirali.saeedi

macrumors newbie
Original poster
Mar 27, 2019
11
2
Hi Folks,

I just got my new 2019 iMac received and setup. I got the base 8 GB RAM option and upgraded myself with Corsair Vengeance Performance Memory Kit 32GB DDR4 2666MHz. Upon first boot, I have noticed an issue. My iMac has recognized 40 GB of RAM. But the speed is shown 2400 MHz, instead of 2666 MHz. Additionally, the About window is missing the "Memory" Tab. Anybody knows what's wrong?
 

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amirali.saeedi

macrumors newbie
Original poster
Mar 27, 2019
11
2
I tried removing the Corsair RAM and the base 8 Gig jumped to 2666. I did some research and it seems there might be a latency mismatch here. The Corsair RAM is CL18, but the base one are CL19. Now I have ordered Crucial, which appears to be CL19 also. Hopefully, that resolves the issue for me.
 

macduke

macrumors G5
Jun 27, 2007
13,421
20,411
I tried removing the Corsair RAM and the base 8 Gig jumped to 2666. I did some research and it seems there might be a latency mismatch here. The Corsair RAM is CL18, but the base one are CL19. Now I have ordered Crucial, which appears to be CL19 also. Hopefully, that resolves the issue for me.
Yeah I ordered the Crucial and have 40GB running at 2667 in System Report.
 

amirali.saeedi

macrumors newbie
Original poster
Mar 27, 2019
11
2
https://smile.amazon.com/Timetec-PC4-21300-Unbuffered-Notebook-Computer/dp/B07H4YBTYY
Does this have any difference in performance other than it being from a non popular brand?
This seems to be $30 cheaper

I would not say non popular since my 2019 iMac was preloaded with 8 Gb of likely the same RAM from Hynix :p I would still go with Crucial since people have seen consistent results. I tried the Corsair one first, but it is reducing the speed to 2400 instead of 2667. Hence returning it.
 

mjy

macrumors newbie
Aug 10, 2019
1
0
I'd like to know if I can add 2 sticks of 2400 MHz to my new I mac without hurting it. I can't afford to buy the 2667 MHz at this time. Someone gave me their 2400 out of their older I mac.
[doublepost=1565530977][/doublepost]I'd like to know if I can add 2 sticks of 2400 MHz to my new I mac without hurting it. I can't afford to buy the 2667 MHz at this time. Someone gave me their 2400 out of their older I mac.
 

marzfreerider

macrumors 6502
Jun 13, 2014
367
254
Germany
I'd like to know if I can add 2 sticks of 2400 MHz to my new I mac without hurting it. I can't afford to buy the 2667 MHz at this time. Someone gave me their 2400 out of their older I mac.
[doublepost=1565530977][/doublepost]I'd like to know if I can add 2 sticks of 2400 MHz to my new I mac without hurting it. I can't afford to buy the 2667 MHz at this time. Someone gave me their 2400 out of their older I mac.

It won't hurt it, they will just make all your RAM do 2400 MHz
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,045
13,075
Seems to me that although you might be able to use software to "measure the difference" between 2667 and 2400mhz, that difference in speed will be UNperceivable to the user "in the real world".

If someone "gave me" 2400mhz RAM, I'd leave it in there and run it that way for the life of the Mac, with a big smile !! ;)
 
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