P55A-UD3 and Graphics Cards

[Guest]

OK gang, I need a hand here understanding a feature of my motherboard. I've read that it's Crossfire X compatible and that it should work well when/if I run my 2 XFX 4770's in that mode. I know they are lower end cards and I probably am worried about nothing, but I've also heard that if you run SATA III and USB 3 you will lose 4 lanes from the PCIEx16 channel and basically make crossfire useless. I've also heard that it will disable the second card if you use SATA III and USB III simultaneously. I mean, this doesn't make sense to me. What if I wanted to crossfire a better card? Say a 4890? Can someone please shed some light on this, or more information on how the P55 works in general?

I am no noob, but I am no genius either so I guess "dummy talk" would be the best answer. My twin brother is using my rig with my 4770's so throwing them into my P55A-UD3 isn't an option at the moment. That would probably be the most direct and efficient way of testing to see what bandwidth I would be running at. But I just am looking for answers and experiences folks have had.

Any comments are welcome.

 

[cyberkuberiah]

when dual gfx are used , the sata and usb work in 2.0 mode , it does not disable the second gfx at all ...

u will have :-

single gfx card at x8 , sata3 and usb 3 at full 3.0 speed.
OR
dual gfx cards at x8 each , sata and usb will work in 2.0 mode , like previous gen ports .

 

[cyberkuberiah]

but wait , the ud3 has the second pcie as x4 only , of the p55 chipset .... the above post is applicable to p55a ud4p ...

for ud3 , it would always be single card at x8 , second card at x4(CF not recommended) , and sata and usb at 3.0 .

gigabyte takes the bandwidth from cpu's pcie lanes for the new sata/usb , asus takes this bandwidth from p55 chipset .... asus is a better solution , as u can get dual x8 + sata/usb in 3.0 speed , but as they use a plx bridge chip with the p55 chip , their mobo's are somewhat costlier ...

 

[cyberkuberiah]

i hope this helps !

 

[Guest]

Not really. My single card in this board is reported as running at 16x when it's stand alone at the moment. So it looks like your wrong.

 

[cyberkuberiah]

no , you have not yet connected 3.0 devices then :-

see the red colored notes a the bottom of this page : http://www.gigabyte.us/Products/Motherboard/Products_Spec.aspx?ClassValue=Motherboard&ProductID=3254&ProductName=GA-P55A-UD3

 

[Guest]

Everything is USB 2.0 that I have. Mouse, Keyboard, Webcam, External 1TB hard drive, Mic, Wireless Adaptor, iPod, Printer, Game Controller. And still says I'm running x16. Do you have this board or are you guessing?

 

[cyberkuberiah]

even when u do connect a 6gb/s hdd or a usb3.0 disk , the x8 will be enough for most single gpu cards , never use dual gpu card for example the 5970 in it .

 

[cyberkuberiah]

the ports need to be connected to a 3.0 enabled device to make them work in that mode , otherwise the gfx work at usual 16x .. of course , ure using gpuz for the mode check , isnt it ?

 

[Guest]

Yeah, of course! I don't think I'll be running sata III or usb III any time soon so I guess I should leave this thread alone and just be happy with what I have until maybe summer when I upgrade again.