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I am getting less than 1mbps on my 100mbps nics!

T

trend

Senior member
I am running a linux server off a pentium 100 (32megs of ram) computer (i used to have windows 2000 and same performace). My only client computer is a laptop 500mhrtz.
I can only get 1mbps tops. I used ftp to test the speed.
but nics are 10/100 and the lights say that they are on 100mbps.
and yes I used twisted pair (I have no hub between computers)


thanks-lee
 
I have no clue about linux, but cant you lock down the cards at 100 in their properties?

That could be one fix in 2000.
 
Probably auto negotiation mismatches. I don't think autonegotiation works between two nics without a hub or switch. Your duplexes are most definately out of wack.

Set each card to operatate at speed=100, duplex=full.

Windows can be done through network control pannel-->network adapter properties.

Linux is probably some driver .conf file.

That 100 mhz/32 RAM computer is going to have a hard time actually keeping up with a 100meg nic. Probably can't push it above 50 megabit. Or the Linux driver could suck. Try to force 100/full for an easy 1st step.

cheers!
 
So you are using a crossover cable? You will definitely not get 100mbps without a switch/hub. How many wires are coming in the crossover cable 4 or 8?
 


<< You will definitely not get 100mbps without a switch/hub >>


Huh? This makes no sense at all, crossovers are fine if you just need to network two machines, and at full duplex speed as well!

I have had that low speed problem as well. Ended up being a bad NIC.

I would NOT set a NIC to force full duplex unless your network supports it. Duplexing is for simultaneous I/O, and most of the time this will only increase speed 20% or so with one TCP session on the network, because acknowledgements can be sent during reception.

 
I have yet to see 100mbps on a crossover cable.. I will double check what you say, because logically it makes sense, but in my experience it isn't so... Also it would depend on how the crossover cable was wired... some are done with just 4 strands and others with 8 strands...

 
It has long been my understanding that only 2 pairs of wires are actually used in 10/100 ethernet. Has there been a change that I have not approved? 😉
 
ok, back to cabling 101 for me... You guys are challenging some long held beliefs... gotta go check the cabling stuff...

 
i see about 8 wires in my cross over cable.

if that helps anyone out

I haven't been able to try any of these suggestions yet, but thanks so much for helping me


thanks-lee
 
The order of the wires is important to reduce crosstalking. That's why u should always use all the 8 wire when making the cable eventhough just 4 of them are used.
 
Right, something to do with the twist of the wires of each pair, and the twist of the pairs themselves around each other, all help to reduce outside interference as well as crosstalk. Which is why you will see all 8 wires included in cables, even tho traffic only moves over 4 of the 8 wires. If I'm wrong about any of this, I'm sure one of our resident net tech's will correct me.
 
TheBigZ: That is correct. Typing while crimping some new cables here at the house.

Soho: I have never seen a network use 100mbps; period. With or without a switch or hub. Sorta like ATA66. It can theoretically get there but it doesn't yet. I'll try again when I finish with the cat5e but I don't think that that will help all that much.

Trend: I would try a different cable if you can. I had a system do this to me and it turned out that someone was monkeying around with the solid core patch cable and stressed it enough to cause a failure. The true reason to have stranded patch cables. Unfortunately I have another 1000 ft spool of the solid core and can't justify being a new spool just for patch cables. Also, since one is a laptop, try it on a different network. It should help you eliminate that NIC is a trouble spot.
 
100mbps is not hard to achieve. I have a 5 computer switched network, and 4 of the 5 computers are running at 100mbps full duplex. computer #5 is an old ISA-only 486 with an old 10mbps NIC in it.
 
SOHO,

Crossover cables work fine at 100BaseT, I think you are refering to how 100BaseT can be implemented using the TX and T4 Standard. 100BaseT-TX uses the &quot;standard&quot; two pairs we all know and love (RX+, RX-, TX+, TX-) but the T4 standard was implemented to try and get 100MB/s over something less than CAT5 by using all 8 wires (not very popular but I think both CISCO and 3COM offer swithces using the T4 standard).
 
When I was just using a crossover cable to connect my puters when I connected my server and my workstation(both using Intel Pro/100 + Managment nics) they both detected 100mb and full duplex and they still do on my linksys 5port 10/100 switch.
 
Trend: What NIC do you use ? Non-busmaster card on P100 might be pretty slow. Was the speed you got out of it, 1Mbit/s or 1Mbyte/s (e.g. ~10Mbit ?). Speed heavily depends from packet size, too. P100 probably isn't capable of more than 200-300Kb/s when you use small packets (tested that at home w/P133 and 100Mbit ethernet, flood ping varies from 2Mbit/s&amp;5-byte packets to 60Mbit/s&amp;10Kbyte packets)
 
Don't force enable full duplex.

10/100 use all 4 set (8 total) of the wires to do 10/100. They run at 25Mhz and 4x as many wire as 10T, which runs at 20Mhz. Thats how they get 10x speed (in theory).

According to the theoratical model of collision, it is impossible to get more than 35% utilization out of ANY multicast network (ethernet is one).

So it might not be a problem, but a limitation instead

 
You CANNOT enable full duplex if you are using a hub, it will not work, you can however use full duplex with a switch or crossover cable.
 
You will NEVER get file transfer speeds of 100Mb/s...I can guarantee that. Check the cable, check the connectors. Remember you have protocol overhead, bla bla bla. Never expect what you're supposed to get.
 
1mbps is too slow. Can you check your cable or nics on another machine? My guess is that there is a problem with the cable.

As far as getting 100mbps on any system, regardless if you are using a hub or a switch(at full duplex) you will only get 100mbps under the best situation, and never full time. You will probably average about 30-60mbps even with the best cards and cables.

I have never heard of the 25mhz X 4 theory. It doesn't make sense to me. Anyone that has done enough cat 5 cabling knows that there are only 2 pairs that are being used. 1,2,3, and 6. two for transmitting and two for receiving. The others wires do serve a purpose, but only to help maintain connection over the distance.

I have never heard of anyone getting anything over 10mbps from a crossover cable between two nics. And unless you are transfering large files between the two computers, 10 mbps is probably plenty fast for games or printers or regular networking functions.
 
Just to clarify, you do realize that it is 100Megabits/second, not 100Megabytes/second right? Oh and the AT&amp;T standard for wiring has 1,2,3,6 for data 4 &amp; 5 are parity? and 7 &amp; 8 are for voice. You can get 100Mb with just 1,2,3,6 as well as full duplex with 1,2,3,6. I have used single CAT5 runs as a double run at 100Mb many times at distances of up to 100m.
 
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