I have 4 PCI E x16 slot but cant fit all 4 GPUs

[ninjapug]

Currently i have a motherboard with 4 PCI express x 16 slot.

However i can only put 3 and there isn't enough room for the fourth one as they are all too close to each other.

What should i do. I heard of extenders but i don't know what type i should get and how to use it.

[CYPER]

http://shop.ebay.co.uk/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=pci-e+riser&_sacat=See-All-Categories

[SomeoneWeird]

Currently i have a motherboard with 4 PCI express x 16 slot.

However i can only put 3 and there isn't enough room for the fourth one as they are all too close to each other.

What should i do. I heard of extenders but i don't know what type i should get and how to use it.

Grab a x16 extender here.

[Chimel]

A picture and motherboard brand & model would help. Is it a EATX motherboard?
If you can't fit the fourth card physically because the graphic cards are double-width, there's not much you can do if you want something integrated with your air cooling system.
Unless it could fit with some cuttings in the back panel or something, or replace the motherboard or computer case with one that supports 4 cards.
You can also replace the single cards with dual ones, like the Radeon 6990 (that's out of stock.)
Check hardware or overclockers forums such as hardocp or the hardware section in this forum.