4890 and 5850 crossfire capatible

[dukerob009]

is a his radeon hd 4890 turbo compatible with a asus radeon hd 5850 for crossfire
ihave to 4890 i want to buy 5850 to crossfire
my computer specs are
1tb seagate barricuta harddrive
16gb ram dual channal 1333mhz for 8gb other 8gb same channal 1600mhz
gigabyte h55m ud2h motherboard
i3 540 cpu clocked at 3.07 ghz dual cor 4 treads
dual 17inch monitors
5 case fans 120mm
dvd drive
cd drive
both ide cords
thermaltake v3 back case
and a 600 watt power supply from corsair cx600 builder series v2
windows 7 pro 64bit

 

[inzone]

Why not buy another 4890?

 

[Guest]

Unlikely as one is DX11 capable and the other is not, easier to EOL the DX10.1 card and move on.

stolen from mousemonkey at:
http://www.tomshardware.com/forum/271370-33-crossfire-4890-5850

 

[de5_Roy]

no they are not compatible for crossfirex. 4890 and 5850 belong to two different card series, batches, generations and so on. amd allows only the same class cards from one gen to cfx e.g. 6870 can cfx with 6850, 6950 can cfx (tri-fire) with 6990. if the model number is 'abcd', then the crossfire compatible cards must have 'ab' numbers matching. one exception is 5770 being able to crossfire with 6770 as the 6770 is a rebadged 5770.
if this is your motherboard, it supports only x16+x4 cfx mode. you'll lose quite a bit of gfx bandwidth on the x4 slot, resulting in poor performance from the second card.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128421
also check out this cfx/sli faq and the compatibility chart in the thread:
http://www.tomshardware.com/forum/245454-33-crossfire-faqs