Adding more RAM to your iMac is an easy way to give your computer more multitasking juice. Look out, open March 8, p.m. PT Intel supports dual-channel architecture, which is optimized for memory in pairs.
Adding more RAM to your iMac is an easy way to give your computer more multitasking juice. Look out, open March 8, p.m. PT Intel supports dual-channel architecture, which is optimized for memory in pairs.
How to: 27-inch 5K iMac (2019) 128GB RAM Upgrade - Save $$$!
Any suggestions as to why? I just upgraded the memory in my iMac and tests with Geekbench show that the modules should indeed be paired by DIMM slot, not by bank. Because here is screenshot how looks 12GB from factory in iMac. Score 5. Is this a good question? On my iMac retina 27 Apple told me to couple the modules by dimm. First, you can assume the factory installed ram is installed correctly so if you are not intending to swap those then do not remove them. This is the correct answer. So, if you are looking at the 4 slots you have a top row and a bottom row regardless whether your imac is lying face-up or face-down. You can disregard what banks they are in. So we didn't have any guidance from them! I have already experienced solving the problem by inversing the DIMM. To add to this Apple was clear as mud! Maybe apple just call them differently. Score 2. I did the same testing with my new 2x16GB modules in my iMac 27" First misusing the word Bank! Dan danj Rep: Rule of thumb is to populate the bank with the same module. Your iMac uses a dual channel architecture to gain the most performance by Interleaving the same sized RAM modules. Please see my other comment above that according to JEDEC standards a bank is not a collection of memory modules; a memory module physical or logical is made up of banks. But still making it confusing! Now let's look at the time point of this post back in where at the time SO-DIMM's where still setup as discreet units Not seen in the context of a channel. A Bank must hold the same RAM chips. Now one last point! I never had a problem since then. And now finally using a better word Channel! Score 1.{/INSERTKEYS}{/PARAGRAPH} Most Helpful Answer. They should both be in DIMM 0. TLDR: it makes sense to group sticks of identical ram so they have the same DIMM numbers and one will be assigned bank 0 and the other bank 1. Fix Your Stuff. Geekbench 4 shows and memory bandwitdh at Daniel MQA is correct. The marking of the slot should tell you the layout if a Bank was across or one on top of the other. Adam Dunn - You are correct this is a mess! Please see my other comment that according to JEDEC standards a bank is not a collection of memory modules; a memory module physical or logical is made up of banks. Turns on but screen stays blank. What I don't understand why Apple is not using dual channel. Thank you! Yes No. Sadly, there is a lot of contradicting information on how the DIMM's need to be installed. Tom Higham. Thanks a lot. The dealer you bought your system from added the RAM. Which it appears you did here. After having this issues my iMac freezed every once in a while I send my iMac to Apple Store and after several days they found the memory was not in the correct position and they changed it so that the same size are on the same DIMM. View the answer I have this problem too Subscribed to new answers. Voted Undo. Don't mix different makes or models of DIMM modules that are the same size! I fully understand what is Dual channel and what advantages it has. You do not need to match a top slot with a bottom slot. But I have it right, Apple confused us with odd terms! Is this correct, or should I insert them physically alternated, so they I have the same modules coupled in the same DIMM? {PARAGRAPH}{INSERTKEYS}Since I know, but I may be wrong, that modules should be coupled, how do I have to do it? Self employed contract worker. Well I thought I had but obviously not. And this are the results I found. Thanks Apple for not using the correct terms and needing to comprehend your mud from right to left! I was very unsettled. Score Don't you just love Apple! Tested on iMac inch Mid Intel Core i7 - 3. Memory bandwidth at previous config was So a significant improvement. MQA Rep: 1 1 1. Thanks Daniel. Back Answers Index. The difference is significant too. Was this answer helpful? Chosen Solution. Thanks for your help Francesco. Dear Dan, I fully understand what is Dual channel and what advantages it has. While it will work this way it is not the most efficient. Yes, Mixing your RAM willy nilly will also work! For example I just upgraded old late iMac RAMs from bottom , and it has 2 RAM modules "horizontally", and 2 slots above again horizontally was empty. Its possible the person assembling the iMac messed up. However it all works great now, so following the rule of thumbs gave good results! Did you tried to inverse the DIMM? I ran the test just once each because numbers were so close. Geekbench 4 shows and memory bandwitdh at 8. April 15 by Adam Dunn. I ran the Geekbench test in both memory configurations, confirming similar findings. Why don't you prove to your self what is the best setup. So I understand your confusion. I tried the other way but I had a lot of issues! If you are filling two empty slots on a 4 slot iMac, just shove in a new matching pair and reboot. At least Apple learned, look at the new Mac Pro memory covers all neatly laid out! Which pair of modules goes in which DIMM slot does not seem to make any appreciable difference. April 16 by Dan. Had to revert to installing by BANK. Manta Driver Kit. I had a problem with my iMac 27 I put by myself the modules with the same size on the same banks. Thanks, I had doubts because the pristine configuration involved two modules in two different banks. The way you have your RAM installed you have lost interleaf services. Andreas is correct! Dan danj. Score 3.