HD 4670 crossfire bridge questions

Hi,I have a 2 part question.I have a 790GX Biostar motherboard in a lian li HTPC case PC-v800b case.I want to put 2 HD4670 video cards in.I noticed some of the newer cards lack the crossfire bridge connection on top of the card.I would prefer to buy theses to eliminate the bridge.My questions are first are there new drivers now that eliminate the need for the bridge or are the new cards designed to eliminate the bridge on a hardware level that the other HD4670 cards still need the bridge.Also i have 2 slots in between the PCI-e slots do i need to find a certain length cable that will work due to the larger distance between slots.

Thanks for the fast reply.Just to be sure the motherboard didnt come with a bridge and i found 73mm and 100mm bridges.Sellers on ebay want alot more for the 100mm.I just want to know if i could get away with a 73mm on a two slot space between cards.

A small section of the GPU is dedicated to crossfire and dependent on the bridge. Without the bridge you will have additional CPU overhead which will generally lower performance as the CPU will have to compute the instructions that would otherwise be handled by the integrated master chip in each GPU that communicates over the crossfire bridge.

I want to the know the answer to this question also. According to ati's chart you need a bridge between 2 4670's. Here's the link to the chart
crossfire chart
Looks like if you have a 4650 and 4670 you don't need a bridge but it says you need a bridge if you have 2 4670's I wonder if this has changed.

If you can crossfire without bridge what is the difference in performance difference with cards using the bridge. Newegg stills sales a Gigabyte card with crossfire bridge.
Gigabyte 4670


The MSI 4570 says crossfire ready but when you goto their website the specifications say crossfire N/A Newegg item
MSI 4670 512MG
MSI's product page
MSI Product specifications
for 2 days now I've tried to find the answers to these question looking everywhere on the internet.

Any experience and benchmarks would be appreciated
Thanks