Officially, Apple provides some models with upgraded video options at the time of purchase, '''but the video is not intended to be upgraded by a third-party.''' So it is "theoretically upgradable" in these systems.
'''HOWEVER you have to use a GPU that is OEM so that it will work -''' ''you can't just plunk any GPU i to the box or you'll have EFI or extension (aka driver) problems''. Your choices seem to be:
Officially, Apple provides some models with upgraded video options at the time of purchase, '''but the video is not intended to be upgraded by a third-party.''' So it is "theoretically upgradable" in these systems.
'''HOWEVER you have to use a GPU that is OEM so that it will work -''' ''you can't just plunk any GPU i to the box or you'll have EFI or extension (aka driver) problems''. Your choices seem to be:
* iMac "Core i3" 3.06 21.5" Mid-2010 256 MB Radeon HD 4670
* iMac "Core i3" 3.2 21.5" Mid-2010 512 MB Radeon HD 5670
* iMac "Core i3" 3.2 27" Mid-2010 512 MB Radeon HD 5670
* iMac "Core i5" 2.8 27" Mid-2010 1 GB Radeon HD 5750
''The best place to score one of these IMHO would be''' e-bay or Google shopping'''.
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