Sorry for necroposting and bad English)
Is it still possible to buy this card? I would like to do some experiments with my m17x r4
Judging by the behavior of A4500 with native vbios, the problem is that the submodule of this bios is waiting for confirmation from the system bios to enable the "4gb above" option and does not allow the card itself to start normally. That's why the author's laptop complained about the absence of the card in SG mode. You can try either to manually disable the blocking module in the bios of the video card, or ask the manufacturer (judging by the screenshots they met and at least responded). Unfortunately I don't see any possibility to modify system bios of Alienware m17x r4, r5 m18x r2, m18 r1 laptops - there are no necessary modules in our bios from Insyde.