Would a 1000Mbps adapter speed up my cable access?

[Medellon]

I was thinking of upgrading to 1000Mbps NIC's. Would this be an improvement for my cable modem and LAN gaming?

 

[CZroe]

No and no. It improves bandwidth. Games don't use that much and a cable conection's bandwidth is typically around one one-thousandth of that speed, so it will not require or benefit from a network adapter capable of 1000mbps.

 

[skriefal]

Most cable modems, DSL modems, and cable/DSL routers only communicate at 10mbps. A gigabit adapter would be a waste here, as it'd simply fall back to 10mbit mode to communicate with your modem/router.

 

[txxxx]

Originally posted by: skriefal
Most cable modems, DSL modems, and cable/DSL routers only communicate at 10mbps. A gigabit adapter would be a waste here, as it'd simply fall back to 10mbit mode to communicate with your modem/router.

10Base-T Half Duplex internally for some ive seen, showing that full-duplex isnt necessarily needed. And they were pretty modern , too.

 

[alpineranger]

If a 10Mps ethernet link is limiting your internet speed (the implication being that you have an outbound connection with at least 6-7Mbps bandwidth), then you are in a truly enviable position.

Here's an interesting tidbit to consider: ethernet efficiency goes down tremendously as the bandwidth of the ethernet link increases, it's an unavoidable phenomenon with a simple mathematical explanation. Ethernet frames are typically of fixed length (in bits). Therefore, the time spent transmitting a file is inversely proportional to the transmission rate (bandwidth). It takes a fixed amount of time for the ethernet signal energy to propagate through the link. Ethernet efficiency hinges on a favorable ratio of transmission time/Propagation time. Basically, you want this ratio to be high, so that collisions can be avoided. In the CDMA/CD protocol commonly used by ethernet today, before a node makes a transmission, it spends a fixed time listening to see if the medium is being used. This avoids a lot of collisions, but it is quite possible that two nodes are transmitting at the same time anyways because they have waited and the medium seems free, but when each begins to transmit, it can't sense that the other has already begun transmitting if the signal hasn't completely propagated through the medium yet. So anyways, propagation time is basically fixed, but with gigabit ethernet you've just done a number on the transmission time, which may seem advantageous but has a adverse effect on the transmission time/Propagation time ratio. In an attempt to limit the effects of this phenomenon, maximum distance between nodes is severly restricted, however, efficiency is still rather low. In case anyone is interested, the actual efficiency of ethernet is given by the following formula: 1/(1+5*tpropagation/ttransmission), which yields a value between 0 and 1 (1 representing 100% efficiency, 0 representing 0% efficiency)


To make a long story short: don't bother upgrading. 100Mbps switched ethernet is still the way to go.

Edit: inadvertent smiley faces removed

 

[CZroe]

I can see how he might think he needs the next thing higher on the ladder:

Perhaps he's using a so-called "10/100" USB 1.1 adapter and booting with some other external I/O eating up the 12mpbs bandwidth (HDD, CD-ROM, Extigy, etc). 😉 They can only claim 100mbps speeds because they have a 256k buffer or something. So it's only 100mbps for 1/400th of a second 🙁 (Sort of like a hard drive's cache, burst speed and sustained transfer rate.)

 

[her209]

Your current nic more than enough. You can even get by with a 10Mbps NIC.

 

[cmetz]

alpineranger, in practice gigE is not CSMA/CD, it's switched (this may actually be mandatory in the specs now, I can go check). So it can run full duplex and many of the timing parameters related to CSMA/CD become non-issues. In general, Ethernet is moving away from being CSMA/CD at all -- switched Ethernets are far more common than "big yellow Ethernet" coax.

 

[alpineranger]

You're right about that cmetz - it totally slipped my mind. (I'm no expert on these matters, and only rarely do I think about/discuss them). I can't think of anyone who runs an unswitched fast ethernet network either.