New iMac extra RAM: instead of standard RAM or in addition?

[Mark B UK]

Thanks to advice on here I recently ordered a new iMac 27in with i9 processor and 2TB SSD but only the basic 8GB of RAM, separately buying 32GB of Crucial RAM (2x 16GB) to install myself. Should I install this in the two vacant slots, so making a total of 40GB, or is it better to remove the original two 4GB modules and put the two 16GB ones in the newly vacated slots? Or, putting it another way, is it better to have as much RAM as possible or only one size of RAM module in my Mac? I'll be using it for LightRoom.

 

[Tom_N]

Apple doesn't list any special requirements.

Apple Support – Install memory in an iMac

Apple Support – iMac memory specifications

Crucial seems to think that the machine has two banks of two slots. So the two slots in use presumably form one "bank" and the two free slots presumably form the other.

 

[Zeee]

Thanks to advice on here I recently ordered a new iMac 27in with i9 processor and 2TB SSD but only the basic 8GB of RAM, separately buying 32GB of Crucial RAM (2x 16GB) to install myself. Should I install this in the two vacant slots, so making a total of 40GB, or is it better to remove the original two 4GB modules and put the two 16GB ones in the newly vacated slots? Or, putting it another way, is it better to have as much RAM as possible or only one size of RAM module in my Mac? I'll be using it for LightRoom.

I was told by people on forums and from the place I purchased my new 27" iMac that sometimes using two different RAM manufacturers can cause issues and you may not gain that extra speed of 40GB. It is better to have the same manufacturer for all RAM cards. The company I purchased it from knew I wasn't going to purchase it from them so they had no stake in it.

I'm assuming it is the iMac, not the iMac Pro? You can change it yourself without voiding the warranty on the iMac. The iMac Pro requires complex disassembly and if you do that yourself the warranty is voided.

I did it myself and it was easy. I removed the 2 4GB Apple Ram cards and put the two new 16 GB cards in the same slots. I went with OWC. This month I will order 2 more 16 GB OWC cards.

Keep the two Apple RAM cards. If you have to take your iMac in for warranty remove the 3rd party cards and install the Apple Ram cards in the same slots they came in.

There are lots of youtube videos showing how to do it. Apple even provides instructions.

 

[Birdstrike53]

Thanks to advice on here I recently ordered a new iMac 27in with i9 processor and 2TB SSD but only the basic 8GB of RAM, separately buying 32GB of Crucial RAM (2x 16GB) to install myself. Should I install this in the two vacant slots, so making a total of 40GB, or is it better to remove the original two 4GB modules and put the two 16GB ones in the newly vacated slots? Or, putting it another way, is it better to have as much RAM as possible or only one size of RAM module in my Mac? I'll be using it for LightRoom.

Hi Mark,

I bought 2019 27’” iMac in April, including basic 8GB of Apple Ram.

Purchased 2 x 16GB of Crucial Ram from Mr Memory after discussing my intentions with them on the phone. Simply used the 2 vacant slots and have not had the slightest issue.

I use it extensively for Lightroom/Photoshop.

https://www.mrmemory.co.uk

Good luck

Dave

 

[Mark B UK]

Thanks to advice on here I recently ordered a new iMac 27in with i9 processor and 2TB SSD but only the basic 8GB of RAM, separately buying 32GB of Crucial RAM (2x 16GB) to install myself. Should I install this in the two vacant slots, so making a total of 40GB, or is it better to remove the original two 4GB modules and put the two 16GB ones in the newly vacated slots? Or, putting it another way, is it better to have as much RAM as possible or only one size of RAM module in my Mac? I'll be using it for LightRoom.

I'm assuming it is the iMac, not the iMac Pro? You can change it yourself without voiding the warranty on the iMac. The iMac Pro requires complex disassembly and if you do that yourself the warranty is voided.

Thanks - yes, it's an iMac, not an iMac Pro. Instructions seem pretty straightforward, which is pleasing.

 

[rkaufmann87]

Always populate the empty slots. It is critical on iMacs that you buy quality RAM, I strongly recommend Crucial.com (not another reseller!!!!) or macsales.com. iMacs like matched pairs so as long as the two vacant slots are populated with a matching pair of DIMMs you should be fine.

I would also recommend installing the new RAM after you have setup the computer initially. Once the initial setup is done, then install the new RAM per the following video https://eshop.macsales.com/installvideos/imac-27-inch-5k-2019-memory/

 

[DaveK2]

I bought the same iMac config as you this past spring - i9, 8 gig ram, 2TB SSD. It is a very nice machine and you will really enjoy it!

As long as the RAM you purchase meets Apple specs in matched pairs there's nothing wrong with adding it to the existing 8 gigs of Apple RAM. My 32 gigs came from OWC MacSales.com for a total of 40 gigs and it has been smooth as butter since day one.

 

[Zeee]

Just to summarize it is not about issues that I stated in one of my threads. I have not read about any actual issues. I should have worded it differently. if you mix RAM manufacturers are you actually getting 40GB RAM speed? How would you know unless you use a clocking app. That was was the point of my post.

 

[Birdstrike53]

Always populate the empty slots. It is critical on iMacs that you buy quality RAM, I strongly recommend Crucial.com (not another reseller!!!!) or macsales.com. iMacs like matched pairs so as long as the two vacant slots are populated with a matching pair of DIMMs you should be fine.

I would also recommend installing the new RAM after you have setup the computer initially. Once the initial setup is done, then install the new RAM per the following video https://eshop.macsales.com/installvideos/imac-27-inch-5k-2019-memory/

I got branded genuine Crucial Ram from a reseller - so what’s the problem?

 

[Mark B UK]

I bought the same iMac config as you this past spring - i9, 8 gig ram, 2TB SSD. It is a very nice machine and you will really enjoy it!

As long as the RAM you purchase meets Apple specs in matched pairs there's nothing wrong with adding it to the existing 8 gigs of Apple RAM. My 32 gigs came from OWC MacSales.com for a total of 40 gigs and it has been smooth as butter since day one.

Thanks! RAM installation (Crucial 2x16GB into the two vacant slots) went really well and the system info is showing 40GB total and 2x 4GB, 2x 16GB as expected. No ay of proving everything's running at the correct speed but also no complaints so far. Slowest part of the process is installing Adobe CC bloatware but that's nearly done; likewise Spyder ElitePro. Like a lot of people I keep old RAW files on an external drive (WD 4TB dual raid) and recent stuff on the iMac so I'm currently transferring about 1TB of RAW files onto the SSD, which looks like it could be 2+ hours as it's coming from a portable HDD which I use as a backup (in future will be replaced with SSD one for speed). So far, so good...

 

[Zeee]

I bought the same iMac config as you this past spring - i9, 8 gig ram, 2TB SSD. It is a very nice machine and you will really enjoy it!

As long as the RAM you purchase meets Apple specs in matched pairs there's nothing wrong with adding it to the existing 8 gigs of Apple RAM. My 32 gigs came from OWC MacSales.com for a total of 40 gigs and it has been smooth as butter since day one.

Thanks! RAM installation (Crucial 2x16GB into the two vacant slots) went really well and the system info is showing 40GB total and 2x 4GB, 2x 16GB as expected. No ay of proving everything's running at the correct speed but also no complaints so far. Slowest part of the process is installing Adobe CC bloatware but that's nearly done; likewise Spyder ElitePro. Like a lot of people I keep old RAW files on an external drive (WD 4TB dual raid) and recent stuff on the iMac so I'm currently transferring about 1TB of RAW files onto the SSD, which looks like it could be 2+ hours as it's coming from a portable HDD which I use as a backup (in future will be replaced with SSD one for speed). So far, so good...

I should have been more clear. There are no major issues but if you don't clock it you don't really know for sure. I'm not interested in that stuff but decided with the amount I spent on the new iMac I'm just going to use 64GB from the same manufacturer. Another 32 is not that much in the big picture. I just delayed getting the other 32 because November was a tight month. Us old retied folks live on a fixed income

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I feel even more confident that soon things will have a wonderful conclusion

 

[Zeee]

I bought the same iMac config as you this past spring - i9, 8 gig ram, 2TB SSD. It is a very nice machine and you will really enjoy it!

As long as the RAM you purchase meets Apple specs in matched pairs there's nothing wrong with adding it to the existing 8 gigs of Apple RAM. My 32 gigs came from OWC MacSales.com for a total of 40 gigs and it has been smooth as butter since day one.

Thanks! RAM installation (Crucial 2x16GB into the two vacant slots) went really well and the system info is showing 40GB total and 2x 4GB, 2x 16GB as expected. No ay of proving everything's running at the correct speed but also no complaints so far. Slowest part of the process is installing Adobe CC bloatware but that's nearly done; likewise Spyder ElitePro. Like a lot of people I keep old RAW files on an external drive (WD 4TB dual raid) and recent stuff on the iMac so I'm currently transferring about 1TB of RAW files onto the SSD, which looks like it could be 2+ hours as it's coming from a portable HDD which I use as a backup (in future will be replaced with SSD one for speed). So far, so good...

I should have been more clear. There are no major issues but if you don't clock it you don't really know for sure. I'm not interested in that stuff but decided with the amount I spent on the new iMac I'm just going to use 64GB from the same manufacturer. Another 32 is not that much in the big picture. I just delayed getting the other 32 because November was a tight month. Us old retied folks live on a fixed income

I should add that I was going to get the 21" but you can't add RAM by yourself. 64GB of Apple RAM pricing is ridiculous. The good people here explained that and I put that cash into a 27". I love it. I'm glad I asked in these forums. I can add RAM when I'm ready to do so.

 

[Michael Fryd]

Choose About This Mac from the Apple menu and click the System Report button. Click on Memory.

What does it say? It may show the speeds of the memory cards. It's possible that your original Apple RAM is as fast as your new RAM. In which case, there is no gain from taking it out. In fact, as a general rule, more RAM is better.

Even if you do take out the original RAM, you should keep it around in case there are any problems with the computer. It's easier to get a warranty repair if the original Apple RAM is installed. If you have third party RAM, and there is an intermittent problem, Apple may blame it on the third party RAM, and not fix anything. If all the parts are Apple, then any issues are clearly Apple's responsibility.

 

[Mark B UK]

Choose About This Mac from the Apple menu and click the System Report button. Click on Memory.

What does it say? It may show the speeds of the memory cards. It's possible that your original Apple RAM is as fast as your new RAM. In which case, there is no gain from taking it out. In fact, as a general rule, more RAM is better.

Even if you do take out the original RAM, you should keep it around in case there are any problems with the computer. It's easier to get a warranty repair if the original Apple RAM is installed. If you have third party RAM, and there is an intermittent problem, Apple may blame it on the third party RAM, and not fix anything. If all the parts are Apple, then any issues are clearly Apple's responsibility.

Thanks - yes, it says all four are 2666mhz, so probably the right decision to leave the two Apple 4GB ones in place.