Well Cat6 is the way to go, but 5e will handle Gb transmission. The best way to find out would be to test it. First, if you do get a Gb switch and you want to know, get a managed switch as it will easily allow you to change the speeds. Short of that, most Ethernet cards will allow you to change speeds in the device manager. Generally, everything works best in automatic mode, but you can change it to 100 Full or 100 Half, etc. Try a computer on 1000 Full and see what speed you get in Amazing Utilities, then try it on 100 Full. Doesn't make sense why a SQL query wouldn't be lightning fast at 100Mbs. But, I don't recall what it was like at 100.
