what difference with pci express x16 and x8

[markiejt]

I understand x16 is better but.

most motherboards have x16 for 1 but if sli or crossfire they go to x8

is it worth the extra £50 for 1 that does dual x16?

 

[mike gunnz]

I'd say no. I ran dual 4870 1gb on a P45 board (x8x8) with no discernible performance loss.

 

[atheos]

Personally i woud pay it as i would like my mobo to be future-proof. Whether it should be priced 50 more is debatable though.

 

[markiejt]

hmm conflicting

 

[mike gunnz]

Personally i woud pay it as i would like my mobo to be future-proof. Whether it should be priced 50 more is debatable though.

What does future proofing have to do with the question asked by the OP?

And are you saying you would pay a £50 premium or you wouldnt? Your statement conradicts itself, or perhaps I'm reading it incorrectly.

 

[mike gunnz]

hmm conflicting

Read this comparison of P45 vs X48:

http://www.tweaktown.com/articles/1472/intel_p45_vs_x48_crossfire_performance/index.html

 

[555BUK]

Depends on the Graphics Card. You really need a GTX280/4870 or above to notice any real difference between an 8x or 16x PCI-E slot. The same will apply for SLI.

For 2x 8800GTX, 2x 4850 or even 2x GTX260 the benefits of dual 16x rails will not be big.

 

[inflynx]

Read this comparison of P45 vs X48:

http://www.tweaktown.com/articles/1472/intel_p45_vs_x48_crossfire_performance/index.html

In this test x48 (i.e. x16) is about 10% faster then P45 (i.e. x8). HOWEVER, it isn't a fair comparison. x48 board is just faster on its own due to being in high-end class and will generally perform better. That does not mean that performance gain comes only from x16.

 

[EvilOne]

PCI-E 16x 2.0 is too quick for any current card, 4870x2 can run on 8x 2.0 without any problems.

The only reason to need dual 16x 2.0 slots is to future proof your system against the next 2-3 gens of cards.

The £50 on a board that supports dual 16x 2.0 slots would be better spent on the actual GPU's. Much much more cost effective. If your running 2x295's then you might think the £50 extra is a bargen tho