the lesser spotted Gigabit Ethernet port ?

Is it strictly true that a 1 Gbps wireless router can transfer data wirelessly from PC 1 to PC 2 at that speed? Even assuming that there is no other wireless traffic, doesn't the fact that the router is having to handle two data streams (PC1 to router, router to PC2) reduce the data rate - maybe to half the theoretical maximum.

I have found that my router, which advertises speeds of up to 400 Mbps, rarely achieves a link speed to a computer of more than about 80 Mbps (*), and the actual data throughput (time to copy file of known size to/from an SMB share) is dramatically less. Copy laptop (Ethernet or wireless) to desktop (Ethernet) achieves close to 100 Mbps for Ethernet for both legs, but about 50 Mbps if the laptop is connected by wifi. That's for hard discs which can achieve much higher disc to disc transfer rates, so that isn't a rate-limiting step.

For accessing the internet, this doesn't matter because the WAN (ADSL/VDSL) connection is the rate-limiting step, but for internal PC-to-PC LAN connections, it becomes important. If I want to access or copy a large file (eg a .TS video file) on my laptop, I always plug it into Ethernet because I get a dramatically better transfer speed. That has been the case for several laptops and for several routers over the years, so it's not just one dodgy laptop's or router's wifi adaptor.

(*) This is for a situation where there are no other wifi networks in range and the laptop is within a few feet of the router.

I'd say you're absolutely correct. Still, that gives you 500mbps transfer speed. I'm not really claiming it will even do that, I'm sure there's processor overhead and whatnot, but I suspect that one could do some number > than 100 mbps.

I can believe that. So if we assume these scale linearly, then a router advertising 1000 mbps should, theoretically, be able to transfer from pc to pc at 200 mbps which would be double the ethernet port.

Of that I have no doubt. There are many factors that affect wireless transmissions, but nevertheless my only point was that a router with a

100 mbps port can still transfer data faster than 100mbps. Yeah, it would make a whole hell of a lot more sense to have a 1000mbps ethernet port, but it's not an isolated case.

Ubiquiti pulled that crap with nearly every M series device they ever sold (with a few exceptions). Using a 40MHz signal, one could get a

300mbps connection, the system was full duplex which gives you a 150 mbps connection in both directions. But since the radios had to connect to the rest of the network with the ethernet port, the 100mbps port was a significant bottleneck.

Agreed

That would be useless.

Being without ADSL would be OK though.