RAM upgrade on iMac 2017 - slot issue

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Level 1

5 points

RAM upgrade on iMac 2017 - slot issue

Hi all

I have just purchased an core i7 2017 iMac 27" which came with the standard 8GB RAM - This came configured with 2 x 4GB cards, occupying slots 1 and 3

I then added my additional 2 x Crucial 16GB cards in the remaining slots 2 and 4 but the machine would not boot up.

I then moved the original 4GB cards to slots 1 and 2 and placed the 2 x Crucial 16GB cards to slots 3 and 4 and it booted up

Questions - Why did it not work like all the literature and YouTube videos told me to configure it and is my system going to work in the best way with this configuration?

Thansk for any thoughts/comments

Posted on Sep 8, 2017 12:07 PM

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Answer 1

den.thed

Level 10

91,708 points

Sep 8, 2017 1:10 PM in response to cozzie62

You tried the new modules in slots 1 and 3 and the original modules in slots 2 and 4...? If it doesn't work that way, contact OWC support and run the problem by them.

FWIW as long as it starts up and runs without errors, more RAM is always better regardless of configuration.

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Answer 2

Dec 26, 2017 9:59 AM in response to cozzie62

I did the same thing with my 2017 iMac 27”. I think I am having intermittent problems with the RAM. I am going to try to re-seat the RAM like ten times to make sure it has a good connection. I tried holding down D at boot up to run the built in diagnostics but it doesn’t see any issues. You could try that and see if it says anything useful.

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Answer 3

rkaufmann87

Level 10

148,494 points

Sep 8, 2017 12:19 PM in response to cozzie62

iMac's like RAM installed in matched pairs. Sounds like your original install was not matched or the new RAM was not seated well.

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Answer 4

cozzie62 Author

Level 1

5 points

Sep 8, 2017 12:26 PM in response to rkaufmann87

Hi

No, the RAM was correctly installed in Slots 1 and 3

Presumably this is as a 'pair' so my installation would meet your comments - So why does my iMac not boot up - Looks like I now have to have it as 'unpaired' in order to boot up !?

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Answer 5

Dec 1, 2017 2:21 PM in response to cozzie62

Hello! Sadly I meet the same issue on a brand new imac 27' 2017. The slots 234 work. The 1 doesn't. After many trials I can't find a solution. Is-it because the machine is in bad shape? Or is-it only a question of software, and if yes does a fix exist?

Thanks,

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Answer 6

cozzie62 Author

Level 1

5 points

Sep 8, 2017 1:07 PM in response to cozzie62

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