Mid 2010 iMac 11,3 i3 RAM upgrade problem

[Canuckfu]

I know there are many threads on this but it seems like people can't agree on how apple and intel define channels and banks etc. It also seems like what is reported as capable is different than what is actually achievable.

I've tried upgrading my ram from the 2x2GB samsung but have had nothing but instability issues. I currently have

2x2GB samsung
2x4GB corsair
2x8GB corsair

No matter the configuration I try I run into issues (except going back to the 2x2GB that it came installed with)

I currently have the 2x8GB in the 2 top slots (those being the 2 slots closest to the monitor) and 2x2GB in the 2 bottom slots (those being the 2 slots closest to the stand). They system recognizes the 20GB installed but shutsdown when I try to run some programs or render graphics etc.

My first question is what is the correct configuration out of the 6 possibilities (assuming I want to max out at 24GB):

Config 1
Top slots: 8x8
Bot Slots: 4x4

Config 2
Top slots: 4x4
Bot Slots: 8x8

Config 3
Top slots: 8x4
Bot Slots: 8x4

Config 4
Top slots: 4x8
Bot Slots: 4x8

Config 5
Top slots: 8x4
Bot Slots: 4x8

Config 6
Top slots: 4x8
Bot Slots: 8x4

At this point I am not interested in learning about dual channel and banks and dimms. I'll learn the why later. Just want to get back to a stable system and need to to know that "what to do" at this point.

Help is appreciated

 

[Canuckfu]

is part of my problem possibly due to the i3 CPU?

I can get the computer to start up when I install 2x4GB and 2x2GB as well as 2x8GB and 2x2GB but not when I install 2x4GB and 2x8GB. However, the neither of the first 2 configuration are stable. That is, if I start doing something even remotely RAM intensive the computer restarts.

 

[justperry]

You should run Memtest on the 2 x 4 GB and 2 X 8 Gb configurations, they are both Corsair, plenty of problems with them.

Go to the link below, down load Memtest and while you are there click on the Guide, it will download a Guide (Text file), read it and then run Memtest in Single User Mode, if there are any Errors send the RAM back and get different RAM, Crucial is one of the one which has little problems, Macs can be picky with RAM.

http://www.memtestosx.org/