how should I place my ram

[50L]

is It ok to place my ram like this?

Or should it be
8
8
4
4
?

Thanks!

 

[MacUser2525]

You need to change them so they are in the proper slots. You see the bank0 and 1 in the graphic you post. Each of those is what is called a channel when populated with identical ram. This being the dual channel ram as it is called. You have an 8 and a 4 in each slot at the moment in the bank 0 or 1. Change it so they are both identical showing as in the same channel (bank) then it is correctly done.

 

[theluggage]

is It ok to place my ram like this?

The 4/8/4/8 arrangement in the screenshot is correct and puts the identical DIMMs on each channel. No need to change your RAM around.

This is really badly documented with a lot of information out there that is either just plain wrong or simply ambiguous ("put matching DIMMs in matching banks" doesn't actually tell you anything).

There's a long thread on it here:

RAM on 2017 iMac 5k

Hello there, I am planning to buy the iMac 5k with Radeon Pro 580. As you all know, it comes with two 4gb ram sticks. I would like to add 16gb more. I know it has 4 slots in total and I know that for the best performance it should go in couples. But I want to add another 16gb when I can afford...

forums.macrumors.com

...in which one user has actually done tests to verify that the 'alternating' configuration enables dual channel mode, while I managed to dig up a PDF that actually described it unambiguously:

https://web.archive.org/web/20110929024052/http://www.kingston.com/newtech/MKF_520DDRwhitepaper.pdf - see page 8.

"For the best dual-channel memory performance on motherboards with the Intel dual- channel DDR chipsets, you must use identically paired memory modules in DIMM sockets 0 of channel A and B. Identically paired memory modules must also be used when populating DIMM sockets 1 of channel A and B. One can, for example, plug in matching 256MB DIMMs in both DIMM 0 slots, and plug in matching 512MB DIMMs in both DIMM 1 slots."

...the proof of the pudding is that Apple ships 8GB iMacs with the two DIMMS in the "DIMM0" positions so there's one on each channel.

You can actually put the RAM in any old how and it should work, but there's a worthwhile performance benefit to having it in the right place.