Upgrading 21.5" iMac RAM (mid-2011 models) to 8GB...

[psmith2.0]

These come with 4GB (two 2GB SO-DIMMs) and have a four-slot design, from all I'm reading. So there will be two open, empty slots available.

If I want to get to 8GB, what is the smartest, most stable/safe approach?

1. Simply add two more 2GB DIMMs to the two open slots ($30 from Crucial)

or

2. Remove the stock Apple RAM and install two 4GB DIMMs ($46 from Crucial)

I wasn't sure if it was important to match the RAM from the same source or not? Can I mix two stock 2GB Apple DIMMs with two 2GB Crucial ones to reach 8GB? Or is it preferable to get two higher-capacity ones (2x4GB) from Crucial and do it that way, where all the onboard RAM is from the same source?

The specs/numbers all match between what Apple uses/recommends and what Crucial offers...but I didn't know if there were known issues or risks in mixing RAM from one source/vendor with another. What's the story on this? Do people typically do this? My gut tells me it should be okay, but I just wanted to hear for sure.

:confused:

It's $16 cheaper to go the 4x2GB "mix-and-match" route (and I won't be stuck with two DIMMs I have to try and sell). But it's worth $16 for peace of mind if that's not the recommended, preferred approach.

Chucker? Eugene? Brad?

:)

[PB PM]

According to Apple's website only the upper end 21" model has four slots, so if you go with the low end it will only have two slots. BTW Crucial hasn't been the best source of RAM the last few years, I'd go for Corsair or just about anything else for that matter.

[psmith2.0]

Oh really?! The specs/info (both at Apple and Crucial) don't make that known. In fact, they make it sound like that model (the 2.5GHz 21.5" Quad Core i5) has four slots.

http://www.crucial.com/store/listparts.aspx?model=iMac%202.5GHz%20Intel%20Quad-Core%20i5%20(21.5-inch%20-%20DDR3)%20Mid%202011&Cat=RAM (see the grey box on the left side of the page, referencing four slots).

From the 2011 iMac user guide at Apple's site...pages 38-39: (http://manuals.info.apple.com/en_US/imac_mid2011_ug.pdf)

Your iMac comes with at least 4 gigabytes (GB) of Double Data Rate 3 (DDR3) Dynamic Random Access memory (DRAM) installed as two 2 GB memory modules. You can replace or install additional 2 GB or 4 GB memory modules for up to a maximum of 16 GB.

...

Your iMac has four memory slots. Two are filled with at least a 2 GB memory module.

They don't go out of their way to say "the 21.5-inch model only has two slots". You'd think they would include that helpful tidbit! And they say they support 16GB of RAM, but you can only BTO the entry-level $1,199 iMac to 8GB.

Confusing, and shaky info.

If you're right, I guess that solves it for me...2x4GB. :)

I'll check out Corsair. I've always used Crucial in the past (4-5 occasions, myself and others) and never any trouble. What's the story? Have they gone down in reliability/quality over time? Or are we talking pricing?

[PB PM]

Edited my post, the 2.5Ghz model only has two slots, while the 2.7Ghz 21" model does have four slots.

[psmith2.0]

Ah...well. Okay, thanks.

That's weird. I wonder why they made two different versions of the same-size model? Would've been easier just to choose one or the other (two slots or four) for the 21.5" and not make it complicated.

No biggie, but now I'm glad I asked...

Apple (and Crucial) need to update some info at their sites to make things a bit clearer.

[709]

The Mid 2011 21.5 comes with 4 slots, the Late 2011 only comes with 2, according to Mactracker (http://itunes.apple.com/us/app/mactracker/id430255202?mt=12). If you have the Mid-2011 I'd recommend spending the extra $16 bucks and installing the 2x4GB in addition to the stock 2x2GB for a total of 12GB. That's what I did with my 27".

[Noel]

The Mid 2011 21.5 comes with 4 slots, the Late 2011 only comes with 2, according to Mactracker (http://itunes.apple.com/us/app/mactracker/id430255202?mt=12). If you have the Mid-2011 I'd recommend spending the extra $16 bucks and installing the 2x4GB in addition to the stock 2x2GB for a total of 12GB. That's what I did with my 27".

Exactly. I'd get the 2x4GB. Either way, it works out best for you: if your iMac has four slots, you get 12GB of total memory; if it only has two, you still get 8GB.

[FFL]

Yeah, you want to go with the 2 x 4GB option, regardless.

Of course, if you want an easy way to know for sure how many slots you have...

About This Mac > More Info > Memory
(assuming you're running Lion).

[psmith2.0]

...and assuming I've got the machine in my possession. ;)

I don't have it just yet, so that's why I was asking here. Prepping and so forth. I know how to do that, but, short of running to a store...

I didn't want to get into a back-and-forth earlier (or dispute anyone's findings), but after getting PB PM's reply above, I found nothing online (Macworld, Ars, iFixit, YouTube videos, Cnet, ZDnet, blogs, reviews, EveryMac, etc.) that said the 2.5GHz 21.5" only had two slots. In fact, everything kept saying "the 2011 iMacs all come with four slots" and things like that.

I could find nothing that said that particular model (the low-end $1,199) only had two slots (and I'd completely forgotten about the education one from later in 2011, so that was never factoring in with me).

[PB PM]

I didn't notice that there was a late 2011 refresh of the 21.5" model, I was just looking at the currently avalible model and asumed it was the same.

[709]

Actually, until this thread I didn't realize how astoundingly cheap RAM was right now. :eek:

That I don't have matched pairs has always kind've bugged me (even if that mindset is a throwback to the old days) and I could certainly use the extra 4GB. So, I'll tell you what. I'll order 2x4GB sticks from Crucial tomorrow - the extra sticks I bought were from Crucial anyways, so there's a comfort there - and you can have my stock Apple 2x2GB sticks (that is, if the thread hasn't persuaded you to go to 12GB ;)). I'll even pay for shipping to make it easy - figure it's a small repayment for all the chuckles you've given me over the years :). I'd never go through the process of selling them anyways and they'd just end up gathering dust.

Lemme know if you're interested. These are from the Mid 2010 2.93 i7 iMac, and by what I can make out from the Crucial site the RAM specs are the same.

[psmith2.0]

Wow, by all means. No hurry whatsoever, but yes! Thank you...check your PM.