X58A-UD7 won't run Crossfire at x16-x16!! ????

[eastley]

Hey guys.

Just realised for some weird reason.

My crossfire runs first card at x16, the second at x8!

My first card is in the first large x16 slot, second card in the third x16 slot as the card blocks the second. Now after reading this should work fine as the board will turn the second slot to x8, and the third to x16.

Why is this not happening?

How can I test this? lol.

Any idea's?

[Dark Mantis]

You don't give us many details to work with, we may be good but we're not mindreaders If you post a few more specs hopefully we can help out.

[Peteruk]

Do you have a card in PCIEX8_2 ?

Do not use the USB 3 ports or SATA 3 ports GSATA6/7 as they linked to the X58 just use the blue ports

Clear CMOS (may need to disable the above in the BIOS) and see what that does.

The X58 on its own allows for 16x 16x only if the bandwidth is not shared with anything else so with the USB 3 ports or SATA 3 ports GSATA6/7 linked to the X58 your slots for your cards will run at x16 x8.        

[eastley]

Well this is weird!

I disabled USB3/Sata3

Still saying the second card is running in x8 mode! So I crank up 3dmark Vantage to see my scores.

http://www.guru3d.com/article/radeon-hd-5850-review-crossfire/19
http://www.overclockersclub.com/reviews/xfx58705850/14.htm
http://www.tweaktown.com/reviews/2967/gigabyte_radeon_hd_5850_video_card_in_crossfire/index4.html

The 3 links above provide 3dmark Vantage Benchmarks, all these three use more powerful processors, either overclocked 920's or a 965 I think.

But my system tears them a new one!

I got:

P21838
GPU 23705
CPU 17664

Now, that is 2000 or 10% better performance over those systems with a weaker CPU, and I am not running the latest drivers either! Wonder what would happen if I upgraded those and overclocked CPU?

So, if it is running at x8, it is not making a difference by the looks of it.