Apple iMac (21.5-inch and 27-inch, Mid 2011) - Manual (Page 44)

44 Chapter 3 Boost Your Memory
Making Sure Your iMac Recognizes the New Memory
After installing memory, make sure your iMac recognizes the new memory.
To check the memory installed in your iMac:
1 Start up your iMac.
2 When you see the Mac OS X desktop, choose Apple () > About This Mac.
You’ll see the total amount of memory installed in your iMac. For a detailed view of the
amount of memory installed, open System Information by clicking More Info.
If the memory you installed doesn’t meet specifications (see page 38), your iMac will
sound three tones every five seconds. If this happens, shut down your iMac and
check the installation instructions again to make sure that the memory is compatible
with your iMac and that it’s installed correctly. If you still have problems, remove the
memory and consult the support information that came with the memory or contact
the vendor who provided the memory.