Jade Falcon wrote:

I'm not to concerned about the loss of performance by having two cards transfers rates docked. But more so with compatibly and micro stuttering.

With so many cards I'm sure you'll get plenty of micro stutter regardless of how many PCI-E lanes you have.

It should work on a technical level, but there is no point to it.

The microstutters are already mentioned, but there are other issues as well. (Software) Stability is going to be a major concern, Crossfire was never particularly reliable in the first place more then 2 cards is likely nightmare fuel on that front. And even if it works, the performance scaling will be garbage and the slower PCIE slots don't exactly help there. SLI already scales really badly with more than 2 cards and Crossfire was always much worse on that front.

i would not bother, unless you are looking for a creative space heater.

A space heater sounds nice for the comming winter.
Maybe ill go with two cards and a nvida card for physics. Or maybe 3 4890s.
Personally I never had mico studering problems with quad sli setups, but crossfire is something Im not very familiar with.

I have 3 cards now. But only 2 water blocks. Ill give the 3 a try with one air cooled and see what its like and maybe add the 4th one or water cool the 3rd depending on what its like.

I still have my old AM2 system (in bits now) that I ran 4 HD4870 in and never noticed any bandwidth issues. These old cards really don't use that much bandwidth. I had two cards running crossfire for many years, then saw two more online cheap used jut a few years ago so grabbed them and had a play. Biggest issues I got was a real memory bottleneck as I had only 512mb. VRAM was just pinned on anything newish. That and the drivers are somewhat lacking these days. I had initially planned to water cool them all and even got water blocks, but after being so disappointing with results I gave up on the project. Was still fun to try though,

Did you have any mico stuttering problems?

For many years 2x 4870 was all I used so it was what I was used to and never noticed it. But looking back yes it probably did have issues just not bad enough to spoil game play for me. Not my videos but this is the sort of thing your looking at https://www.youtube.com/watch?v=CfkPGJET7e4 and https://www.youtube.com/watch?v=Q7YbZrgs9IU