For first, i would like to say sorry for my bad english (poland here). So lets back to topic.
I got some old PC card - its Ati Radeon 5770 (yes, im know its nothing special)
Of course, card dont show bootscreen, but in Mac overview show as a Ati Radeon HD 5000 Series 1024MB - its becouse card aint flashed? And i read somewhere, when mac showing card as HD 5000 Series, mac do not use card in 100%. It is true?
Can someone give some topic where are guide step by step how do flash of radeon in Yosemite? I find one, but its for Moutain Lion
Really thanks for any help
greets and wait for reply