Rom chip location on Saphire 4870 The area circled in green on the wide shot is made more legible on the tight shot. Please note no disassembley of card or fan is needed to see this particular chip. So it is hopefully the same on Mac one. Would be great to get a scan of back of Mac card, in high enough res to read the text on board. This is a 128K ROM chip on a 4870 of the PC variety. Part number matches 128K item. (I have bumped it up in Photoshop to make it easily readable) Good news is I had a look at the PC 4870 ROM in Hexedit. There looks to be a standard ROM, a BUNCH of dead space, and then more code, followed by more dead space. Alltogether, the blank portion of ROM is between 20-30%. So, there may be space in there for EFI.