PCi 2.0 lanes issue

[thewhitemonk16]

Hi there, I am looking to build my first machine, I have been doing a lot of reading and seem to be able to get my head around most of the technical bits and pieces. One thing I am really finding hard is 16x, 8x and 4x lanes for graphics cards.

I want to possibly do sli/crossfire and the motherboard I am looking at has 2 x PCi 2.0 graphics slots one which is 16x and the other is 4x. Is 4x good enough for this or do I need to look at a motherboard with 16x and 8x or two 16x lanes?

Any help would be much appreciated as i am a newbie to all this. Thanks

 

[decto]

Motherboards may have multiple x16 PCI-e slots but on the cheaper boards only x4 are connected electrically on the second x16 slot.

For crossfire / SLI you should aim for x8 x8 minimum.

If a board is listed for SLI support it it usually x8 x8 minimum though these boards are £50 + more expensive than the basic x16 x4.
Worth considering if you'll really use it or if you could put the extra to a better single GPU.

Also make sure you have at least 2 other slots between the two PCI-E x16 slots as this allows better clearance for cooling on the upper card. The double width coolers fitted take up quite a bit of space.

AD

 

[thewhitemonk16]

Ok thanks for that input Decto, much appreciated.

Just to run this past you i was looking at Gigabyte Z68 which has 1 x PCI Express 2.0 x16 , 1 x PCI Express 2.0 x16 ( x4 mode ) - Which seems no good for SLI/Crossfire

Instead then I will go for the Gigabyte GA-Z68XP-UD3P which has 1 x PCi Express 2.0 16x and 1 x PCI Express 2.0 8x lanes - Then they work at 8x and 8x. This seems to have plenty of room for cards as you sugested. Sorry if you are repeating yourself, been saving up for months now. just don't want to make a stupid mistake.

Apologies if this is in the wrong section as well, but it is still a graphics card question.

Thanks again Daniel

 

[decto]

I have the GA-Z68X-UD3P which is almost the same board. Only difference is the GA-Z68XP-UD3P has HDMI output and the lucid quicksync feature.

It's currently setup perfectly with 2 x GTX560ti running at x8 x8

The cheaper Z68 board only does x16 x4 therefore the second card will not operate to it's full potential and SLI is not supported.

It's a good solid board. The ASrock is also highly recommended but about £30 more expensive. The Gigabyte does everything I need.

AD

 

[thewhitemonk16]

Cool, that puts me more at ease anyway Bit scary when Im hoping to spend like a £1000 on everything

Thanks for your input I will buy the Gigabyte GA-Z68XP-UD3P then.

Thanks for the help! Dan