can u crossfire an onboard with a external?

im looking at this board
Newegg.com - ASUS M4A785TD-V EVO AM3 AMD 785G HDMI ATX AMD Motherboard

i have a ATI 4890 HD

would those be able to work together?

Hello naturalphenomen.
As far as i know with SLI and XFire both cards need to be the same, or at least very close, the system will only be as fast as the slowest card, also, when you fit the PCIe card it will disable the on-board card.

I have just built another system and moved away from Xfire to a single high spec card.
It runs just as nice as my system that has quad graphics, go figure that, and is by far, much more stable.

I cant say i am a big fan of Asus, the last two boards i had from them were really bad. The striker was RMA'ed FOUR times, yes four times and they still couldn't get it right, the P5Q Premium went back twice, i switched to a Gigabyte board and cant fault it in any way. Runs a lot cooler than the Asus board too.

Take a look at the new USB3 Gigabyte boards, just as good as Asus, runs cooler, and will probably be a lot cheaper too.

Hope this helps, good luck and let us know how it goes.

would u mind helping me find a great board for a AMD hexa core?

also can u make sure it supports thuban? heres the cores im thinking about getting


Newegg.com - AMD Phenom II X6 1055T Thuban 2.8GHz 6 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Six-Core Desktop Processor

Newegg.com - AMD Phenom II X6 1090T Black Edition Thuban 3.2GHz 6 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Six-Core Desktop Processor

this evo i,am using now works well but is known to be fussy on boot with the faster dd3
just dont install asus own apps as they are still quite naff, most ddr3 boards will run hex cores with a bios update (check the venders website) but i,d rather save the money as optimised software for 6core will be months away yet.