nic speed calculation needed 1

[nelljack]

I have 100.0 Mbps speed on my nic card. Can someone tell me how to calculate the time it would take to download a 109MB file?

 

[dippncope]

You need to know more then the speed your NIC card is capable of. What is the speed of the router? What speed are you getting from you ISP? Is that dedicated or shared bandwidth from ISP and your own network. To many variable involved to supply an answer with information you provided

 

[dippncope]

But this may help answer your question

http://www.speedtest.net/

 

[kmcferrin]

Actually, the speed of the NIC (note that "NIC card" is actually redundant) is probably completely irrelevant in this case. Far more important will be the speed and congestion levels of the networks that exist between your PC and the system from which you are downloading the file.

Assuming that you are downloading a file from a server on the Internet, let's make the following additional assumptions:

1. The server's internet connection is faster than your internet connection.

2. The networks between your ISP and the server are not congested.

3. Your internal network is not congested.

4. That you are not sharing your Internet connection with other subscribers (which is normally NOT the case with cable modems).

Then the determining factor will be the speed of your internet connection. Assuming (again) that you have a dedicated connection capable of the following speeds, the estimated times are:

1.5 Mbps (roughly a T1) - approximately 10 minutes
6 Mbps (common for cable and DSL) - approximately 2.5 minutes
15 Mbps (typical for "Turbo" branded cable) - approximately 1 minute

________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Windows 7
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator

 

[nelljack]

Sorry I didn't give more info and the redundancy.

I have wireless connection. The "tech" there told me I should be able to download the 109MB file in about 10 minutes. It took 1hr 15min and then I got nothing as the connection timed out just before finishing. Needless to say I was ticked.

If this is not enough info then I will not ask any more.

Thanks to all in advance.

 

[Nelviticus]

The 100 Mbps figure you quoted sounds like a wired ethernet card, not a wireless card. Wireless connections generally have a 'speed' of 11 Mbps (802.11b), 54 Mbps (802.11g), 108 Mbps (super-G or G+) or as much as 450 Mbps (draft-n).

But that figure is the 'throughput' or 'data rate' - the maximum number of bits per second you'd get if you had an absolutely perfect connection (which would never happen). Even then a large proportion of the bits that get transmitted aren't part of your data, they're control signals and error-correction signals.

The actual relevant speed of a wireless connection (i.e. how fast you can transfer a file) depends on a lot of factors but I've found that with a good connection it's about half the theoretical speed - I got about 5 Mbps with 802.11b and about 50 Mbps with super-G on a good day.

So that's the background, now you can work out file transfer times. There are 8 bits (b) to the byte (B), so one megabyte is 8 megabits. A 1 Mbps connection (1 megabit per second) could therefore transfer 1 MB of data in 8 seconds. A 109 MB file would take about 14 1/2 minutes over a 1 Mbps connection.

I'm guessing that there's something wrong with your wireless connection if it took you 1hr 15 mins.

Nelviticus

 

[gbaughma]

I usually use a factor of 10 instead of 8.... at least in the modem days, you had a stop bit and possibly a parity bit. So it was about 10 bits to make an 8-bit byte.

With TCP/IP, it's worse than that.... I don't remember all of the specifics off the top of my head, but there's header information in there as well.... but not for every byte, obviously. MTU and packet size come into the picture... the smaller the packets, the more often the header information gets sent along. The larger the packets, the less header information, but if it has to re-send a packet (especially over wireless) then the larger packet has to be sent all over again.

To say that you can download a 8MB file in 8 seconds at 1Mbit would never happen.


Just my 2¢

"What the captain doesn't realize is that we've secretly replaced his Dilithium Crystals with new Folger's Crystals."

--Greg

http://parallel.tzo.com

 

[kmcferrin]

If you're using a wireless connection then it's completely different. You will suffer with a great deal of network congestion because wireless networks all use shared media (the airspace), much like hubs did back in the day.

For example, let's assume that you have an 802.11g access point and wireless card. The total maximum speed of this connection is 54mbps. But if there are other wireless networks in the area (and in most neighborhoods and business parks, there are MANY wireless networks) then the frequencies used for 802.11g in that particular airspace will be shared between all of the wireless networks within range, meaning that each individual network will have only a fraction of that 54mbps.

The only way around this is to use a different frequency than everyone else. Of the 11 frequency "channels" available to 802.11g, there are only three that have no overlap with other channels.

It other words, wireless networks are great for mobile connectivity, as long as you don't need a lot of bandwidth.

________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Windows 7
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator

 

[nelljack]

Thanks all for your input. I upped the speed I was getting from the ISP and it seems to be working faster. It still took 30 mintues to download a 29MB file. I suspect the ISP hadn't switched me over at the time.

If I did have a problem with my wireless connection what would I look for first? Would a new nic be of use? I am not sure if any more physical memory can be added to my pc but willing to check on it. What else could be the problem?

I say it is wireless as the signal comes into an antennae then through wires connected to my pc. It would be nice to have a laptop with wireless as then there would be no wires at all. That I know of anyway.

Again, thanks in advance.

 

[kmcferrin]

Oh, you have a wireless ISP. That's wild. It's going to totally depend on what kind of signal it is. It could be satellite, RF, or even microwave.

________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Windows 7
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator

 

[nelljack]

Thanks all. I'm done.

 

[gbaughma]

Wow... another fine example of "not enough information"....

1) I have a 100Mbps NIC
2) I have wireless
3) I have a wireless ISP

.... over dialup. (Just kidding)



Just my 2¢

"What the captain doesn't realize is that we've secretly replaced his Dilithium Crystals with new Folger's Crystals."

--Greg

http://parallel.tzo.com

 

[SimonDavies]

Well everyones pretty much covered it, unfortunately the speed of your NIC really had no bearing on your actual receive rate due to the fact that it's from the ISP.

To give you an example.

I have a wired 1gb connection. I can download a 350mb file in about 3 minutes.

I also have a 108mb wireless connection. That takes me about 4 minutes to download the file.

Why? because the ISP I am downloading via has me on a super fast connection (24mb), that gives me nice fast downloads but still not as fast as when I am transferring data on my lan between two machines with 1gb cards in them.

Please try to remember that you're always going to only get the fastest connection from your slowest one, by that I mean you can have teamed gb cards but if you're using them on a 100mb switch you're still only going to get the data across at 100mb.

Simon

The real world is not about exam scores, it's about ability.

 

[JimInKS]

To test your internet speed use these websites:

http://www.speakeasy.net

or

http://www.speedtest.net

These sites will test the connection speed between your computer and the internet. The internet is usually less busy early in the morning and a good time to see what the best speed you can get is. Try the test several times to get an idea of the average performance of your connection. In the evening it will probably be much slower.

I would be happy with an internet speed that is around 70% or higher of the connection speed you are subscribed to.

 

[kjv1611]

[LOL] @ gbaugma

I guess the OP just finally gave up?

nelljack,

If you're still reading, have you check the flux capacitor?



--

"If to err is human, then I must be some kind of human!" -Me

 

[Noway2]

On a slightly more serious note, I have occasionally pondered: wouldn't an inductor be a flux capacitor?