I have a iMac 24, 4bg, 2.66 GHz Duo, currently running on 10.5.8. I want it to run faster and with the latest OS. Can this machine be upgraded to 8GB?

First, open System Profiler (Applications > Utilities folder) and copy Model Identifier

Dwayne Huggins wrote:

... Can this machine be upgraded to 8GB?

Last question first: maybe. It depends on your specific model iMac. Determine that with

 > About this Mac

and clicking More Info...

Under Hardware you will find your specific Mac model identifier. If it is iMac9,1 the answer is yes.

... I want it to run faster and with the latest OS.

First buy as much memory as you can. Buy memory from either OWC / MacSales or Crucial.

Next:

To upgrade from OS X 10.5.8, you must first buy Snow Leopard by calling the phone number in the Apple Online Store: 800-MY-APPLE (in the US). Snow Leopard costs $20, or $30 for a five user license.

Make sure your system meets Snow Leopard's requirements:

Mac OS X 10.6 "Snow Leopard" System Requirements

To install Snow Leopard for the first time, you must have a Mac with:

• An Intel processor
• An internal or external DVD drive, or DVD or CD Sharing
• At least 1 GB of memory (RAM) (additional RAM is recommended)
• A built-in display or a display connected to an Apple-supplied video card supported by your computer
• At least 5 GB of disk space available, or 7 GB of disk space if you install the developer tools

After you install Snow Leopard you can decide if you want to upgrade OS X to the latest version, Mountain Lion. Mountain Lion is available in the Mac App Store, which is available to you after upgrading to Snow Leopard.

Make sure your system meets the requirements for Mountain Lion:

Mac OS X 10.8 "Mountain Lion" System Requirements

To install Mountain Lion, you need one of these Macs:

• iMac (Mid 2007 or newer)
• MacBook (Late 2008 Aluminum, or Early 2009 or newer)
• MacBook Pro (Mid/Late 2007 or newer)
• MacBook Air (Late 2008 or newer)
• Mac mini (Early 2009 or newer)
• Mac Pro (Early 2008 or newer)
• Xserve (Early 2009)

Your Mac needs:

• OS X v10.6.8 or OS X Lion already installed
• 2 GB or more of memory (RAM)
• 8 GB or more of available hard disk space

If your system does not support Mountain Lion's requirements, you may be able to upgrade to Lion. To do that you must call Apple again to order a download code. Redeem the download code in the App Store to download Lion.

Make sure your system meets the requirements for Lion:

Mac OS X 10.7 "Lion" System Requirements

Mac with an Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon CPU

Core Duo CPUs are not sufficient for Lion

• 2GB of memory (RAM)
• OS X v10.6.6 or later (v10.6.8 recommended)

To determine which Mac you have, what kind of CPU it uses, and how much memory is installed:  > About this Mac

The specified 2 GB minimum is barely adequate for either Lion or ML. They will run in 2 GB but you may not like its performance. 4 GB is a more realistic minimum.

Yes, that will run 8GB RAM (same model as mine).

It can also be upgraded all the way to Mountain Lion, but watch out for problems with applications - most will need upgrading and PPC only apps like Appleworks or Office 2004, or several Adobe apps, won't work at all.

^^^ what he said.

🙂