Go to a hardware / paint store. Get a box of TSP, trisodium phosphate. Add one half teaspoon to dishwasher detergent cup, with your detergent, at each load. Also, to save energy, turn off heated wash, and on heated rinse...
In very small print, at the bottom of the warning…
“The initial production of the base model for the 21.5" iMac didn't come with a slot for the SSD. Later production models included the SSD slot, but there's no way to determine if the 2012 21.5" iMac with a 2.7GHz processor has the SSD slot without opening it up to see if it's available. If you have already opened the iMac up and it does have an SSD slot, this SSD is compatible.”
Go to this web page.
https://eshop.macsales.com/item/OWC/SSDI...
At the bottom, it says Mac (21.5-inch Late 2012)
(October 2012)
Model ID: iMac13,1
2.7GHz
with a :”Not Compatible” warning.
Click on the “compatibility Info” link.
In very small print, at the bottom of the warning…
“The initial production of the base model for the 21.5" iMac didn't come with a slot for the SSD. Later production models included the SSD slot, but there's no way to determine if the 2012 21.5" iMac with a 2.7GHz processor has the SSD slot without opening it up to see if it's available. If you have already opened the iMac up and it does have an SSD slot, this SSD is compatible.”
Thermal sensor to fix fans...
https://eshop.macsales.com/item/OWC/DIDI...
PCI-e SSD is here - https://eshop.macsales.com/shop/ssd/owc/...
2.7 came with or with out the PCI-e SSD connector, it should be on all others...
Only way to tell is to take apart the 2.7 and look...
Early 2.7 GHz models did not have the slot on the motherboard.
Later ones did.
OWC Aura 6G fits...
https://eshop.macsales.com/shop/ssd/owc/...
Tempreture sensor from Other World Computing, https://eshop.macsales.com/item/OWC/DIDI...
Temperature sensor.... https://eshop.macsales.com/item/OWC/DIDI...
Update, 3770S, no go, Ivy Bridge vs Sandy Bridge...
Quad core in a Core Duo may be possible, OS at the time when people tried did not recognize quad core processors...
Did some major research, there are three iMac styles,
Late 2009, with LGA775 socket on the 21.5, and LGA1156 on the 27.5;
Mid 2010 with LGA1156 socket;
and Mid 2011 with LGA1155 socket.
27.5 MB953xx/a, MC511xx/a, and MC814xx/a support 95 watts.
Late 2009 and Mid 2011 are 65 watts otherwise,
and Mid 2010 73 watts...
Possible processor upgrades-
1156 socket, i7 860S or 870S, 82 watts;
1155 - i7 2600S or 3770S, 65 watts.
For LGA775, anyone want to try a QUAD core 9450S or 9550S, 65 watts?
If you look at the following specs for the Intel i7 processors with the LGA 1156 socket, there are two i7 with low power use. 82 verses 95 watts.
One is 2.53 GHz, listed as i7 860S,
the other is 2.67 GHz, listed as i7 870S
https://en.wikipedia.org/wiki/List_of_In...
There is also an i5 low power processor, i5 750S, 2.4 Ghz, https://en.wikipedia.org/wiki/List_of_In...