TCP/IP Problem: 10Mbps instead of 100Mbps; Why?

[patrickdrd]

Hi everyone!

My PC is on a network with two PCs and instead of 100Mbps data transfer (Local Connection icon), I get only 10!!!
(I calculated that after having transfered a big file)

Does anyone know what is the cause? Is it some network card setting that I'm missing?

Thanks in advance!

 

[slipfrase]

If you are using a hub, the highest speed you can get is 10mb. You need to buy a 100mb switch to get 100mb connectivity for a network which has more than 2 pc's. (I am counting 3 pc's in your network)

 

[chris13]

There were 100MBit HUBs in the market, too (I'm using one of these). But in the SOHO market as rare as 10MBit switches

Whatever, check if your HUB/Switch supports 100MBit/s.
Look at the device and your network card, probably there are LEDs showing if the connection is at 100MBit/s.

Sometimes (more often in former times) devices failed to detect the speed of the device to which they are connected (auto-sensing). Have a look at the properties/device seetings of your network cards. There should be a parameter called "link speed" (or something similar). Probably it is set to "auto detect". Change all cards to "100MBit/s half duplex". If that works, you may try full duplex, too.

Until now we worked on the "link speed", that is independend from the number of PCs in the net or what they are doing in given moment.

If everything is OK, check the speed of data transfers. Use some really big files, not a big number of small ones.
To eliminate influence of disk reads/writes, you can use a tool like "netio32", but transferring files should be fine to recognize 10 or 100MBit/s.

Sometimes link speed seems OK, but when data is to be transferred, everything slows down.
Possible causes:

- network card driver (use the ones supplied by card manufacturer)
- windows network parameters were "tuned"
- cables, plugs, sockets
- network cards reached end of live
- HUB/Switch

Easy way to check: Get a "crossover" cable to connect the 2 PCs directly. That way just the cards and drivers and windows itself remain for further analysis.

good luck,
chris

 

[bcastner]

Test it with more precision:

http://dast.nlanr.net/Projects/Iperf/#download

If you get 45% or so of the 100 mbs, consider yourself done.