We have completed further testing on SR5 5GHZ cards today, related to this issue.
Formerly we had 4 SR5 cards in one system, at 10mhz of spectrum, in adjacent channels (5745,5755,5765,5775). As mentioned in my prior post in this thread, that caused major loss of thoughtput, loss of connectivity, etc...
When tested later on, we founf 40mhz of spectrum was required to space these apart---and things operated properly at 5745, 5785, 5825---leaving on 3 cards able to be operated in one machine in the 5.8ghz spectrum.
Today we split up the card into two different machines, rackmount metal cases located indoors, seperated about 2 feet apart from each other, in the same small 6'x5' room. One system had card set for 5745 and 5785, and the other at 5765 and 5825---all set for 10mhz frequencies. That resulted in a minimum of 40mhz of space between card in either individual machine, and atleast 20mhz between each machine. Testing showed no loss of thoughtput or packet loss whatsoever this time, and all 4 cards are useable now. There was issues with adjacent 10mhz channels even on different machines however, so 20mhz is really needed there, and still 40mhz spacing insie the same machine. This gives you a maximum of 3 cards in one machine, or 5 cards across 2 machines (2 + 3)--based on required frequency spacing.
Your situation may be slightly different, if you can spread the machiens much further apart, or worse if you use regular tower cases (and not heavy duty thicker rackmounts as we did). Using outdoor mounted APs may yield completely different results for you. This did not take into case antennas either---we used (4) 90-degree vertical sectors. Mixing and maching horizontal and vertical sectors may have yielded slightly different results.
We will be continuing our testing on the 2.4GHZ spectrum, in 10mhz frequencies this week, and will report back on results. We are configuring every thing to rise in between the 1,6,11 major 20mhz channels, so that leaves very little room for us to play in. As it is, in one machine, we could only get two SR2 2.4GHZ cards to function well in one machine, utilizing 2422(or)2427 and 2447(or)2452. Not sure how we are going to get more than that when using two machines, but we'll see what we can come up with
Hope that helps some of you guys out...
SMA