Why do you think broadcast traffic is what is causing your issues? There are ways to turn off some of the nonsense broadcasting that might be going on if that is the case.
I would run a sniff on your pc during the day, busy part of the day.. Let it run for say 30 minutes. Then look at it and see what portion of the traffic is broadcast.. I would assume that switch has the ability to do IGMP snooping - which can lower the amount of multicast traffic to your devices as well.
I doubt your using SSDP, so that could be turned off.. A sampling of the type of broadcast traffic your seeing, and I am sure you could reduce the amount of it quite a bit!! With some changes in your OS settings, disable services.
Off the top I would think by default all your PCs are able to be browser - when there is NO point to that, so they are sending out that traffic I bet - so simple disable of computer browser service on all your PCs other than your servers you would want to be master browser would reduce broadcast.
Grab wireshark (free) log some traffic for period of time - and then lets look at the type and amount of broadcast traffic your seeing and we can see what we can do to reduce it.
I grabbed only a few seconds of traffic on this work network (which I do NOT MANAGE BTW - my box just sits on this network) There is a bunch of clean up I would do, and things I would do WAY DIFFERENT!!
But as you can see - only a few seconds and quite a bit of nonsense that could be removed. Got users running dropbox with lan sync enabled - maybe they are syncing with other workers? Doubt it - notice the browser looking for web URLS - thats because they browsers are not correctly setup not too, and they query dns and it dies not respond because only the proxy here can do outside dns queries. Notice the machines announcing they can be browser, pointless for them to do that. See the multicast SSDP traffic - again pointless on a work network! We sure an the hell are not using any UPnP stuff...
Dhcp is about the only thing on there that should be seen
And you could reduce the amount of that depending on your lease time, etc.
And that was only a couple of seconds and pointed out stuff that could be done to reduce broadcast/multicast traffic. So lets see yours.. Run it for longer or just start with a few seconds and we can point out stuff I am sure.
Post up the statistics breakdown, etc. You looking to reduce nonsense traffic - are you using IPv6? Bet you all your boxes have all that stuff enabled sending out noise for something you have no use of, etc.
I find it unlikely that broadcast/multicast is killing your network - but sure its possible you got some storms going on?? We can clean up the stuff that does not need to be there for sure, prob won't make much impact on your performance overall - but its good house keeping regardless of any performance impact.
and just if your curious, no none of that is from my box
IP Address. . . . . . . . . . . . : 10.56.41.184
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 10.56.41.1