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Fast Ethernet but actual speed is 10MB only

By harrisdy ·
Hi,

I just bought a Linksys 5-port workgroup switch to network my 3 laptops running Vista, Vista, and XP using CAT5e UTP. The LED in the switch indicates 100MB and Full Duplex but when I am copying files from one computer to another, the copy speed shows 10MB only. Is this normal? Or is there anything I need to do to utilize the 100MB?

Thanks in advance for your help.

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Without knowing the specific makes and models of laptops...

by OldER Mycroft In reply to Fast Ethernet but actual ...
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definitely sounds like the NIC's in the laptop

by Nimmo In reply to Fast Ethernet but actual ...
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You also need to remember

by OH Smeg In reply to Fast Ethernet but actual ...

That the Max speed is not what you will achieve when you actually transfer files across the LAN it will be slower than the Max Possible Speed of the Network.

If the Network Speed is showing as 10 MBS in the Task Manager that is a speed of the computers Network Card/Interface whatever not the actual speed of the LAN/Network.

Col

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confused...

by harrisdy In reply to Fast Ethernet but actual ...

I might be a little confused here... please help me out.

NICs speed for both laptops are 100Mbps... both set to Auto Negotiation. Link Speed in Task Manager and the switch shows 100. When I try to transfer a 400MB file, the transfer rate is about 10MB/sec. I understand that the 100Mbps speed of NIC is the rate at which it sends 1's and 0's out to the media. But what about the transfer rate? I think its wrong for me to think that both should be 100, right? can anyone explain?

thanks!

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Here are a couple of explainations

by IC-IT In reply to confused...

Copied from Experts Exchange;

first let's look at a comparison of bytes to bits:

Bytes/sec. bits/sec.
12.5 MBps 100 Mbps ethernet
so theoretically a 100Mb file would take 100 / 12.5 = 8 seconds

If we assume TCP, protocol overhead will consume some of that, so say 11.0 MBps is available for data with normal packet sizes

100 / 11 ~ 9.1 seconds

This is assuming that both machines have disk subsystems and ethernet adaptors and drivers that can send and accept the data at that rate. A busy cpu, badly fragmented disk, irq sharing and driver implementation can all affect performance. Operating systems come into play as well as tasks are prioritized so that something like a file transfer won't slow all other tasks to a crawl. A netware server will generally see file much higher server performance than windows98 on the same hardware because it's written from the ground up to do that and little else.

Now the intermediate networking equipment comes into play. In a full duplex crossover cable scenarios one should have no collisions and minimal latency. Using a (good) hub will add some latency and drop you down to half duplex so it will also introduce some collisions. Bandwidth drops as latency goes up. (see http://www.babinszki.com/Networking/Max-Ethernet-and-TCP-Throughput.html) The use of a switch between two nodes can actually be slower than a hub as the hub has only to repeat the packet whereas the switch has to examine the packet and it's span tree to find the destination, though a switch starts becoming an advantage very quickly when more machines are sharing the wire.

So you have to test your particular setup to see what bandwidth you're getting and work on each bottleneck individually, optimize each machine and operating system for file sharing.

Another example of factors to consider (an apple site, but same principles).

http://www.atpm.com/network/problems/network_speed.htm

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I agree with the post above....

by ---TK--- In reply to confused...

I use to have the exact same question, Till I researched it. All it is, is bottle neck after bottle neck... But through some research I found out that there a couple tweaks you can do, in the registry, that will speed up your networking speeds (appear to). This is at your own risk... Remember what you do so you can undo it if things dont turn out the way you planed...

http://tinyurl.com/TK-net-1

* you can also use the command line command: copy <file_name> NUL and if you are seeing the same speeds then the bottle neck is your HDD...

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You are getting the full speed... need to understand some mathematics :)

by zk_pit In reply to Fast Ethernet but actual ...

Port speed = 100 Mbps = 100 Mega bits per second.
Transfer Speed = 10 MBps = 10 Mega Bytes per second=10*8= 80 Mbps (Mega bits per second)

So please mind the bits and Bytes. 1 B(Bytes) = 8 b (bits).

So LAN port Speed shows in bits and transfer speed shows in Bytes.

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Reponse To Answer

If the OP doesn't understand it after 3 plus years, they aren't
going to! Let the zombies sleep.

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