Ethernet over coax speed question

[Soundhound]

I have a coax cable running from the front house to the back house and want to connect my router to the iMac back there that serves up music and movies etc to the rest of the house. It's currently connected via wifi, but there are dropouts etc.

I've been pointed to a few different devices that can run ethernet over coax, such as this one:

http://www.netsys-direct.com/proddetail.php?prod=NH-310C&cat=27

there are a variety of them, and they all seem to say they have speeds in the 100mps to at the most 500 mps. My questions is this. How fast are current Airport and Ethernet speeds? I know they speak of Gigabit wireless, so does that mean 1000mps and up?

If I'm currently using wireless in this case, do you think switching to coax would slow things down a lot, or would it work ok?

thanks!

 

[Makosuke]

Ethernet currently tops out at 1Gbit (1000 Mbit), which will probably get in the range of 80% of that in real-world use if the devices at both ends support gigabit speeds. n wireless is 150Mbit, minus a fair amount of overhead. There are dual-channel n devices that claim to get 300Mbit over n wireless if the device at both ends support this, but to my knowledge no Apple products currently do, and I'm not sure how much of that theoretical 300Mbit is usable in practice.

So basically, if you're getting 100Mbit over coax, then it's possible that n wireless will be faster, depending on how good the signal is. If you'll get 500Mbit, then the only thing faster is going to be a gigabit ethernet link.

I'd probably go with the hardwired link, whether it's coax or a new twisted pair cable. The unknown, of course, is whether you'll actually get the speeds claimed over coax; my guess is that you will, but not having used coax-based networking in about 15 years when we switched from 10Base2 thin coax to cat5 I can't say for sure. (I can say that 10Base2 sucked horribly, but that was due more to poor wiring and the network topology than coax itself.)

 

[Soundhound]

Thanks! That explains the whole shebang in exactly the detail I needed. Much obliged!

Ethernet currently tops out at 1Gbit (1000 Mbit), which will probably get in the range of 80% of that in real-world use if the devices at both ends support gigabit speeds. n wireless is 150Mbit, minus a fair amount of overhead. There are dual-channel n devices that claim to get 300Mbit over n wireless if the device at both ends support this, but to my knowledge no Apple products currently do, and I'm not sure how much of that theoretical 300Mbit is usable in practice.

So basically, if you're getting 100Mbit over coax, then it's possible that n wireless will be faster, depending on how good the signal is. If you'll get 500Mbit, then the only thing faster is going to be a gigabit ethernet link.

I'd probably go with the hardwired link, whether it's coax or a new twisted pair cable. The unknown, of course, is whether you'll actually get the speeds claimed over coax; my guess is that you will, but not having used coax-based networking in about 15 years when we switched from 10Base2 thin coax to cat5 I can't say for sure. (I can say that 10Base2 sucked horribly, but that was due more to poor wiring and the network topology than coax itself.)

 

[Soundhound]

Ok I lied. One more question? What speed does g wireless run at? I have some older Expresses in use in the network, and I think if there are any g expresses at all, the whole network runs at g speed. Is that right? So I'm wondering what g speed is, since that's probably what I've been living with.

thanks!

 

[Makosuke]

Wireless g maxes out at 54Mbit, leaving out some of the nonstandard multichannel things a few manufacturers push.

Whether one device slows the whole network down to g speeds will depend on whether it's dual-band or not, but if you have older n hardware and some g stuff on the network, you've probably been running at 54Mbit (or lower, depending on other factors).

You can check easily enough: Open up Network Utility in your Utilities folder, and under the Info tab select Airport from the drop-down list of interfaces. It should tell you what speed it's connected at (though of course this could still be higher than the actual throughput you get).

The easiest thing to do, however, is just copy a large file and time it. That tells you what throughput you're REALLY getting in the only use case that matters: the one you want to use it in. If it's, say, 40Mbit (remember 1MB is equal to 8Mbit, so multiply your Finder-based calculations by 8), then you're pretty much maxing out g speeds. If you're only getting 10, then either range or interference is a bigger problem.