- Nov 06, 2017 I have had my 27' iMac for over a year now and really need to upgrade the ram as it is running so slow. I know where I am going to get my ram from but I would like to know how many ram slots.
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- About the SD and SDXC card slot on your Mac. Some Mac computers feature an SD (Secure Digital) or SDXC (Secure Digital Extended Capacity) card slot that lets your Mac read and write data to SD media, such as digital camera memory cards. Up to 2TB (iMac Pro only) You can use a passive adapter like the one shown here to make MiniSD, MicroSD.
- The 27-inch iMac with Retina 5K display is loaded with up to 8GB of dedicated VRAM. It delivers visual effects and 3D graphics that exhibit raw power in its most polished form. On top of that, you get advanced video editing capabilities. Now you can edit multicam projects in Final Cut Pro X with up to five streams of full-resolution 4K video.
- I just upgraded the memory in my 2017 iMac and tests with Geekbench show that the modules should indeed be paired by DIMM slot, not by bank. The difference is significant too. With the same modules in different banks I get a memory bandwidth of 30 GB/s, with the modules in the same bank (but different DIMM slots) memory bandwidth drops to 16 GB/s.
- Apple Apple iMac MNED2LL/A (Mid 2017) 27' All-in-One Desktop Computer 27' Retina 5k Display; Intel Core i5 7600K 3.8GHz Processor; 8GB DDR4-2400 RAM. Memory Slots (Total) 4. Memory Slots (Available) 2. 260-pin SO-DIMM. Maximum Memory Supported. Hybrid Drive. Flash Memory Capacity. SSHD Capacity.
You've certainly tried a lot of configurations; my comment here would be to address the new configuration of the slots in the new iMacs.
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The slots used to be two rows with two slots next to each other and you matched two modules horizontally. On the new iMacs, the slots are arranged vertically; the 'matching' needs to be slots 1 and 3, and/or 2 and 4. The confusing thing is that the graphics in About this Mac still shows them arranged the way they used to be (which makes no sense whatsoever). The other problem is that they are still calling the banks 0 and 1 which makes it more confusing; however, I'd say that the two '0' banks are slots 1 and 3, and the '1' banks are 2 and 4.
As I don't have a new iMac with that arrangement, it's a bit difficult to respond as to the configurations; however, it appears that your arrangement in your # 1 (8/2/8/2) should be the way to do it; your arrangement in #2 (8/8/0/0) would be the last thing I'd go with, but you said it is working...
Edit:
I just now looked at the tech specs from Apple and here is what it says:
It says configurable to 16 or 32 GB - I would read that as: the only supported configurations are 16 or 32 - not 20, 24, or whatever? That may be the answer as to why the two 8 GB modules are working.
If that is the case, I would try it though putting one each 8 GB in slots 1 and 3 so they are matched.
Here is the link to the specs:
Aluminum iMac Q&A - Updated July 14, 2016
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How do you upgrade the RAM in the 'Late 2009,' 'Mid-2010,' 'Mid-2011' and 'Late 2011' (21.5-Inch and 27-Inch) Aluminum iMac models? What type of RAM do they use? How much RAM do they actually support?
Please note that this Q&A explains how to upgrade the RAM in the 21.5-Inch and 27-Inch Aluminum iMac models that have all aluminum cases and a flat, thick edge around the display. Apple refers to these systems as the 'Late 2009,' 'Mid-2010, 'Mid-2011' and 'Late 2011' models. They can be identified by model numbers A1311 and A1312.
EveryMac.com also provides RAM upgrade instructions for the earlier 20-Inch and 24-Inch Aluminum iMac models that have black plastic backs (model numbers A1224 and A1225) as well as the 'Late 2012' (and subsequent) 21.5-Inch and 27-Inch Aluminum iMac models that have all aluminum cases with edges that taper sharply around the display (model numbers A1418 and A1419).
The memory upgrade procedure in these 21.5-Inch and 27-Inch iMac models is easy, but different lines use different memory types and there are differences between official and unofficial RAM capacity as well. Precise identification can require a bit of work, too.
Photo Credit: Apple, Inc (21.5-Inch & 27-Inch Aluminum iMac Models)
Identification Help
If you're not sure which Aluminum iMac you have, these 21.5-Inch and 27-Inch models can be most simply identified externally via EMC Number -- located inconveniently under the 'foot' supporting the computer -- and in software by Model Identifier for the purpose of upgrading the RAM. These models can be uniquely identified when combined with a secondary identifier like display size, processor speed and/or processor type.
To locate the model identifier in software, select 'About This Mac' under the Apple Menu on your computer and click the 'More Info..' button. If the iMac is running OS X 10.7 'Lion' or later, you will need to click the 'System Report' button after clicking 'More Info..' as well. As always, EveryMac.com has carefully hand documented each EMC number and model identifier for your convenience.
These identifiers for each of these 21.5-Inch and 27-Inch iMac models follow:
![Computers Computers](/uploads/1/2/5/2/125223150/471075350.jpg)
iMac | Subfamily This is the “Guru Mantra” when it comes to internet Roulette. Place a dollar each on both red and black and start with two dollars on green zero. Double the amount of bet on green zero after every 10 trials and you would encounter zero within first 60-70 trials you would end roulette every time with a. Jan 23, 2019 The best way to win money on Roulette (or to minimize the risk to lose money, if you wish) is to focus on the outside bets. How to win in roulette. Place two bets of equal amounts on two outside bets: one bet on an even-money play and the other on a column or dozen that pays 2 to 1. For example, place one bet on black and one bet on Column Three, which has eight red numbers. That way, you have 26 numbers to hit, 4 of which you cover twice. Dec 30, 2019 So the only way to win in roulette–and this is completely random, never guaranteed–is to bet on less than all the numbers on the wheel. You also want to play bets that pay better than even money. You can place a variety of bets, but most of them aren’t worthwhile. | EMC | Model ID |
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Mid-2010 | |||
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Mid-2011 | |||
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Late 2011 |
If your 21.5-Inch or 27-Inch iMac is not listed above, you have a later'Tapered Edge' iMac model.
EveryMac.com's Ultimate Mac Lookup feature -- as well as the EveryMac app -- also can uniquely identify these models by their Serial Number, which is listed on the underside of the foot along with the EMC number and within the operating system alongside the model identifier. More details about specific identifiers are provided in EveryMac.com's extensive Mac Identification section.
RAM Types & Actual Maximum RAM Capacities
All of these 21.5-Inch and 27-Inch Aluminum iMac models have RAM slots that are readily accessible via a small 'door' on the underside of the display. However, the type of 204-pin SO-DIMM and the actual maximum capacity varies.
Specifically, the 'Late 2009' iMac (iMac10,1 and iMac11,1) models use 1066 MHz PC3-8500 DDR3 SO-DIMMs whereas the 'Mid-2010,' 'Mid-2011' and 'Late 2011' iMac models all use 1333 MHz PC3-10600 DDR3 SO-DIMMs.
Officially, the education-only 'Late 2011' iMac model will support a maximum of 8 GB of RAM, but it actually is capable of supporting 16 GB. The rest of these models all officially support a maximum of 16 GB of RAM -- and this also is the actual maximum RAM for some models -- but other models actually are capable of supporting 32 GB under certain conditions.
As it can be confusing, these details definitely are easiest to visualize as a chart:
iMac | EMC | Model ID | SO-DIMM | Max |
1066 PC3-8500 | 16 GB | |||
1066 PC3-8500 | 16 GB | |||
1066 PC3-8500 | 16 GB | |||
1066 PC3-8500 | 16 GB | |||
1066 PC3-8500 | 32 GB* | |||
1066 PC3-8500 | 32 GB* | |||
1333 PC3-10600 | 16 GB† | |||
1333 PC3-10600 | 16 GB† | |||
1333 PC3-10600 | 16 GB† | |||
1333 PC3-10600 | 16 GB† | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 32 GB | |||
1333 PC3-10600 | 16 GB |
* As first reported by adventurous EveryMac.com readers, and carefully confirmed by site sponsor Other World Computing, these models can support up to 32 GB of RAM if they are running Mac OS X 10.6.3 'Snow Leopard' or higher in 64-bit mode and have been updated to use the latest EFI version. They are limited to 16 GB of RAM in 32-bit mode.
† Specifically note that the 21.5' models from the Mid-2010 line (iMac11,2) and the entry-level 27-Inch model -- the iMac 'Core i3' 3.2 27-Inch (Mid-2010) -- only support 16 GB of RAM whereas all models from the Mid-2011 line -- 21.5' and 27' -- actually support 32 GB of RAM. If you have a 21.5' model (or the entry-level 27-Inch 'Core i3' powered Mid-2010 iMac), please be very certain to identify it precisely to avoid potential disappointment when upgrading the RAM. The 21.5' Mid-2010 models use the 2389EMC number whereas the 21.5' Mid-2011 models use 2428.
RAM Upgrade Instructions
Upgrading the RAM in all of these 21.5-Inch and 27-Inch iMac models is similar and easy.
The process basically consists of (1) place a soft towel (or anti-static mat) on a table or other flat surface, (2) place the iMac 'face down' on its display on top of the towel or anti-static mat, (3) unscrew the access panel on the bottom of the display edge, and (4) change out the SO-DIMMs.
Apple kindly provide silkscreened pictures that cover the RAM upgrade steps on the bottom of the iMac 'foot' itself and these images should be reviewed before proceeding with the RAM upgrade.
However, even better, Other World Computing provides helpful step-by-step videos of the precise procedure for each model:
21.5-Inch & 27-Inch 'Late 2009' iMac RAM Upgrade Video
21.5-Inch & 27-Inch 'Mid-2010' iMac RAM Upgrade Video
21.5-Inch & 27-Inch 'Mid-2011/Late 2011' iMac RAM Upgrade Video
From watching the video, it should be clear that upgrading the RAM in these models is simple. However, if you do not feel comfortable -- or have the time -- to perform the upgrade yourself, hiring a professional always is a good option.
iMac RAM Purchase Options
Just because RAM meets the minimum listed criteria does not mean that it will necessarily function as intended in a particular Mac. Be sure to buy from a quality vendor that has tested their RAM with your Mac to ensure full compatibility.
In the US (and many other countries), site sponsor Other World Computing sells memory for all iMac models for do-it-yourself upgrades.
In the UK and Ireland, site sponsor Flexx sells Aluminum iMac compatible memory with free shipping. The company provides flat rate shipping to France, Germany, and Switzerland and inexpensive shipping for all of Europe, too.
In Canada, site sponsor CanadaRAM sells memory for all iMac models with guaranteed compatibility, fast shipping, and no customs.
27 Inch Imac Computer
In Germany, site sponsor CompuRAM sells quality memory for all iMac models with affordable delivery country-wide and in person pick up and professional installation service available in Munich.
In Australia, site sponsor RamCity sells Aluminum iMac compatible memory with a lifetime warranty and fast, flat-rate shipping Australia-wide.
In Southeast Asia, site sponsor SimplyMac.sg sells Aluminum iMac compatible memory with free delivery -- and optional upgrade service -- in Singapore and free shipping to Brunei, Hong Kong, Macau, Malaysia, Myanmar, New Zealand, the Philippines, Singapore, South Korea, Taiwan, Thailand and Vietnam.
Also see: How do you upgrade the hard drive in the 'Late 2009,' 'Mid-2010,' 'Mid-2011' and 'Late 2011' (21.5-Inch and 27-Inch) Aluminum iMac models? What type of storage do they support? Is it even possible to upgrade these models?
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