I have a WRT54G v6 router and I am trying to get higher speeds from a wireless network, I have set up a dish and a cantenna and is going really well about 18-22dbi gain which is very noticeable but I have a question, does an Ethernet cable speeds up the transfers? Like the Upload and download speeds will be faster? like a high speed cat7 or cat6 cable that can transfer data at much higher frequencies, Will that help? I have cat 5 and get around 13Mbps, will cat 6 get me 16 or 17? or the router can't handle it?.Also another question is how can I make the gain on the dish higher?.
I am using DDWRT
More abouthelp antenna cable
In your case the Ethernet connection is not the bottleneck, your wifi is, so changing the Ethernet cable will make no difference.