I need to know 101% if the RAM on the new (the ones released this month (with the new Intel chips I believe... Skylake?)) iMac Retina 5K is upgradeable, and if 24GB (2x4 + 2x8) is an acceptable setup.
If so, I would also like to know if 1600MHz memory would be ok to install, given that the stock memory inside the computer is 1867MHz. I'm guessing it will just all run at the lower frequency, but I'm not sure.
Thank You in advance!
OS X Yosemite (10.10.5)
The 5K iMacs, ie. the 27inch models do feature user upgrade-able RAM.
The 4K iMacs, i.e the 21.5inch models not not.
The 27 Inch models do have 4 slots. so the setup you propose should work.
The memory will clock down to the lower speed, so all will be at 1600mhz.
You should only install RAM that is guaranteed to work on the iMac by the manufacturer. OWC(macsales.com) and Crucial guarantee their RAM.
Stay away from bargain priced offers such as Kingston, and other low priced options since they tend to cause much more trouble than its worth.
I was looking at doing the same thing with my new imac 27" that is due for delivery at the end of this week. I am told it can take a max of 64GB 4x16GB
I'm in the UK which meant OWC would most likely take a long time and probably incur some import charges.
Crucial UK don't list any ram for the late 2015 yet, i asked them when they might expect it and they couldnt answer.
But i picked up an 8Gb 1867MHz module for £40 from mrmemory. it is listed as being late 2015 compatible. so hopefully it will work to boost my ram until i go crazy on it as new larger modules become available and prices drop.
I dont need any more than 16Gb ram for now, but in the future i might well.
Just a heads up for everyone, I bought and installed an additional 8GB of corsair vengeance PC3-15000, 1866 MHz ram, and it made the system underclock the ram to 1600 MHZ. I am not certain how to establish what ram will run at 1866 MHz on the system. Crucial shows no compatible memory at this time and OWC memory seems to cost a little more and doesn't list latency specs so it's a bit hard to know what you are getting.
Same here. I bought and installed 2x8GB of G.Skill Ripjaws F3-1866C10D - 16GRSL along with the stock memory 8 GB, 2x4 GB (Micron) and the iMac boots up to the total of 24GB but it's running at the lower clock speed @ 1333Mhz. The stock RAM is also 1867 Mhz. How weird. So I removed the stock RAM and just use the G.Skill. It's now running at the speed of 1867Mhz. But i only got 16GB of RAM :-(
HELP! iMac Retina 5K RAM upgrade.
