How to crossfire with Motherboard Asus P5Q PRO P45

[Richard B Rufus]

Here I currently have P5Q PRO with graphic card as a Sapphire HD 4870 TOXIC 512 MB.
I would like to buy a 2nd HD 4870 TOXIC for a CROSSFIRE but my motherboard will operate 2 * 8X.
How many losses as a percentage of 16x will I have??
Taking into account this parameter what is the difference compared to an HD 4870 X2?
In this scenario my crossfire will still stood up?
Thank you for any answers.

[ApPy10]

Around 10 to 20% depending on the game

[Richard B Rufus]

Thank you for you answer but on what basis have you done that calculation?
For you the crossfire toxic 512 is still up? 219 € and 389 € for the X2
By knowing what is running at 780 mhz? 750 mhz for the X2
I'm about to buy but I'm afraid that I will regret it later.
Apparently in 2048 the X2 memory above 1 GB is not operated by the OS, is what I have heard?
The only advantage for me is that the X2 could turn into 16 X
Thank you to me but because of the referrals I am confused, I do not know what to do.

[Techguru01]

The crossfire on P45 is on average 17.3% slower than X38 with differences ranging from 5 to 33%! We have here we must say a blow to P45 while technically there should not have differences. Indeed the management of the memory is slightly more efficient on X38, but surely not in such proportions!

Games & bench tested are newer and also expected to see much differences at home. I hope this is of concern to a driver or bios optimization alongside Intel (latent worries?), The P45 loses interest in crossfire. In any case, even though in absolute 10/15% are not so large that, in relative terms there are enough differences, making the switch to some games playable even to limit unplayable.

http://www.tweaktown.com/articles/14...ion/index.html