Memory Upgrade Issues

Apparently the new memory is not compatible with your Mac. Return it.

Your iMac10,1 requires 1066 MHz RAM.

Here's the specs for you late 2009 21.5 iMac 10,1:

204-pin PC3-8500 (1066 MHz) DDR3 SO-DIMM

Look at OWC for reliable ram for your machine. Even if you don't buy their's you cannot just buy generic ram that just happens to have the same specs. It needs to be documented as for macs since macs are picky about the ram and will have unpredictible results.

What brand and where did you get the RAM?

There were many threads here on the 2009/2010 iMacs and problems with them not being able to recognize the full 16 GB of third party RAM; however OEM RAM seemed to be fine - here is one thread:

https://discussions.apple.com/thread/2567907

As I mentioned, there are many threads; your description sounds exactly as some of the ones detailed at the time. My solution was to stay with 12 GB ( 2 x 2 oriignal RAM and 2 x 4 added RAM). I purchased the RAM at OWC (macsales.com); others decided to purchase OEM RAM to get to 16 GB.

Is it Kingston value RAM? There are many reports of problems with any brand value RAM.

If you can, I'd return it and check out OWC; however, with your iMac, I'd talk to them first before going to 16 GB - they were well aware of the problems on the 2009 and 2010 iMacs at the time.

babowa, you sound like someone who does know some answers.

I just bought a new 27" iMac with the 3.1 CPU and 1 G video. want to upgrade to 16 GB memory from the 4. Checked with OWC and bought two (2) 8 G which they indicate is for the iMac .. I agreee with you as to OWC and have used them on my previous machines.

BUT, seeing something in some publication made me nervous about the use of two 8s as opposed to four 4s, which is quite a bit cheaper. I called Applecare who I normally trust, and after a great deal of fishing around and checking with senior rep came back with "using only two in place of the 4 since the manual says 2 or 4 G modules" would probably void the warranty if something went wrong that could be a result of memory. I personally don't think any one was using the 8s at the time it was written, but ...

Having just had a 1 TB HD fail and replaced by Applecare, I am aware of the necessity of playing by their rules.

Have you any way of verifying this , one way or the other?? I haven't opened the package yet.

PS: I know OWC will warrant the memory - but, that is "THE MEMORY" nothing else.

In hopes,

Ed

Well, thanks - I'm not an authority nor do I work for Apple, but I appreciate it! Having said that:

First, all iMacs come with only 2 slots populated; but, from what I've read, it appears that if you're going to max it out, balancing the load (so to speak) just seems more logical. It also seems to be addressed here - a bit confusing, but:

http://support.apple.com/kb/HT3918

If you read it carefully, it says you can use 2 or 4 GB RAM in each slot; 8 GB is not mentioned, therefore I'd say it's not supported by Apple. It may work and OWC will guarantee their stuff, but if you'd need to deal with Apple for anything, they would have the opportunity to say "not covered because it was caused by unsupported RAM". Since I tend to try to carefully follow the mfr's rules so as not to void any warranty, I'd stick with either adding 2 x 4 GB for a total of 12, or buying 4 x 4 GB (but make sure the problems encountered with the earlier iMacs are no longer an issue by asking OWC).

Thanks, just as I said, and that's what they said. I'll call OWC and listen to them assure me there is no problem until I ask if they want to warrant the machine and operating system.

There is no end to gotchas, regardless of Apple, Microsoft or you name it. The new way.

again thanks,

ed

IF you go with something other than what is officially supported by Apple (but has been tested by OWC as working), then I'd suggest you tuck away your original RAM modules somewhere safe; if you ever need to send in the Mac for anything, swap the original RAM back before doing so. I always keep mine. Aside from that, it's also good to have it in case of a suspected RAM failure for testing purposes.

I bought Kingston memory; it didn't work. It wasn't "value RAM" as I recall either. Returned it and bought from OWC. As babowa says OWC is a reputable vendor.

The answer you got from Apple regarding warranty problems, while technically correct, is highly unlikely to occur. You would have to go out of your way to break something, which would qualify as abuse anyway. Defective or incorrectly installed memory modules may cause your computer to not work, but they will cause any internal component failure.

Apple considers memory upgrades a do-it-yourself project and even provides the instructions. Of course if you fail to follow instructions it's your fault, not theirs.