Hi all. I have purchased a refurbished iMac from Apple recently. It is the 2011 model, 21" screen with an i5 processor at 2.5GHz. Because i purchased it in the refurbished section, apple did not allow me to use the upgrade option by adding more RAM. Hence i did not know the maximum amount of RAM that it can support. I have had a look at the brand new iMac section and found that Apple would only allow purchaser to upgrade up to 8GB of RAM for this particular model, so is this an indication that it can only support 8GB? However, i have had a look on the 'RAM upgrade guide' on the apple website. It somehow states that 2011 21" iMac can support up to 16GB? (see here http://support.apple.com/kb/HT1423?viewlocale=en_US#1) So my question is, can my iMac only support 8GB or 16GB? Thanks in advance.