Upgrade/replace Motherboard on Late 2009 iMac?

[reillycm]

Hi I have a late 2009 model iMac. The 27 inch screen is BEAUTIFUL and the case is in perfect condition, but unfortunately I am not able to upgrade the OS, and I'd like a much faster CPU. Is it possible to replace my entire motherboard with a current one? If so, can you please guide me to a list of motherboards that might work? Lastly, is this something I need to have done at the Apple store, or could it be done at home by carefully following the directions?

Specs on my iMac are listed below:

Model Name: iMac
Model Identifier: iMac10,1
Processor Name: Intel Core 2 Duo
Processor Speed: 3.06 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 3 MB
Memory: 16 GB
Bus Speed: 1.07 GHz
Boot ROM Version: IM101.00CC.B00

3.06 GHz Core 2 Duo (E7600)
Intro Date: October 20, 2009 Disc Date: July 27, 2010
Order No: MB952LL/A Model No: A1312 (EMC 2309)
Subfamily: Late 2009 Model ID: iMac10,1
Std RAM: 4 GB Std VRAM: 256 MB
Std Storage: 1 TB (7200 RPM) Std Optical: 8X DL "SuperDrive"

 

[eduardrw]

Cant answer the technical feasibility part of your question about a motherboard replacement for your late 2009 iMac.
I would expect the only remotely feasible option could be a i7 2.8GHz motherboard from the 11,1 iMac.

It however does not make sense in my mind for the following reasons:
- motherboard upgrade including cpu would likely be > $700 if you do it yourself.
- you most likely would have to/want to upgrade the GPU too = additional $$
- if you have not opened your iMac before - this is major surgery
- you can upgrade the OS to the current OS x 10.9.5 (http://www.everymac.com/mac-answers...icks-compatible-macs-system-requirements.html)
- it is cheaper and gives much better performance to replace the DVD drive with an SSD as boot drive (see OWC disk doubler - 240GB is sufficient), keeping the existing hard drive
- upgrading RAM to minimum 8GB gives also significant speed boost.
- the only real speed-boost with a CPU upgrade to a i7 is for video rendering where the software uses mutilple cores.

I have added a 240GB SSD to my 11,1 iMac (i7 2.8GHz) and its like a new computer - significant speed increase!
That is the best bang for the buck.