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10/100MB Network speed question

V

vdg

Member
I have 3 computers connected through a SWITCH using cables CAT5. The network cards are different brands(Linksys,Compaq,Intel) but all of them are 10/100MB.
I'am running win2k on 2 of them and Solaris on the other one.
The NIC setup in all the OS-s is 100MB full duplex and I can see on the switch that is OK: it has some lights saying what type of connection it is(100,10,half or full duplex)

..with all this setup I cannot get more than 700-800KBs transfer rate between them..and I have no ideea why!!!

I tried to setup the NIC-s on AUTO detection and I got the same results as when are setup with 100 full duplex...700-800Kbs

any ideea what can be wrong???

vdg

Ps: the Switch is a D-link 8 port with auto negotiating
 
I use to test the speed just a simple FTP program🙂 from one computer to another..and then when I burn CDs with the files located on another computer I have the option on NERO 5 to test the speed of the max transfer and I cannot get more than 6x write speed..about 900kb/s
 
If I am not mistaken, Nero probably means 900KB/sec. (B=Byte), which is 7.2Mb/sec (b=bit).

7.2 Mb/sec will be typical for 10Mb/sec Network.

Log to the following site and down load the program. And take a ?certified measure?

http://www.qcheck.net/

 
make sure your cables or in good shape and have never been bent too far or been stretched... Also make sure they are no where near any AC sources like a power strip or something that will cause interference.
 
Yep..that's the only thing that remains to be done: to change all the cables🙁

I'll run that test and let you know the results.
 
OK I did the test: Throughput 5.810 Mbps with Data Size 1000 kBytes and if I change the data size a bit..is going down the perf. but no with much...
So..looks like is preaty bad...any ideea what to do..beside to change the cables?
 
Try distributing the cables across the switch such that there is as much space as possible between the connections. If you already have them that way, try connecting them all bunched up together (one side or the other, or all in the middle). Depending o the ASIC architecture, there is sometimes a gain by either spreading them out, or bunching them together.

Go to dslreports.com and check their tweak section and speed test. They also have a small app called 'Dr.TCP' that let's you tweak the registry to change some of the networking parms. The Tweak section will make some recommendations.

Try hard setting the speed/duplex on the NICs. Some switches confuse themselves with the auto-negotiate thing. It may be showing that it's correct, but can still be wrong.

Try slowing down the connections...back down to 100/half (on every NIC), if it still sucks, try 10mbps (on every NIC). Power cycle the switch and reboot the computer each time you change things.

Good Luck

Scott
 
With any NIC in half-duplex mode, you can pretty much assume that your maximum throughput rate will be approximately HALF what the network is rated at - IE, 10Mb/s half duplex = maximum throughput of about 5Mb/s (or 625KB/s). This is due to the collision-based nature of half-duplex Ethernet. As traffic increases, so do collisions.

The best way is to hard-set your switch port settings to match the maximum throughput of your NIC. Autosensing works fine 90% of the time, but is certainly not 100% accurate. This is especially important with Solaris - Most switches won't autodetect the proper settings of a Solaris machine. If you can't lock the port settings on the switch, change your solaris machine to 100/half and it should work OK.

If you have a managed switch (rare, unfortunately, in the home arena) look at the port settings - Are you seeing a lot of errors (CRC's, long, shorts, etc.)? If so, there's probably a duplex mismatch.

But.. If you have a card at 10Mb/s, half duplex, the speeds you are seeing are to be expected.

- G
 


<< With any NIC in half-duplex mode, you can pretty much assume that your maximum throughput rate will be approximately HALF what the network is rated at - IE, 10Mb/s half duplex = maximum throughput of about 5Mb/s (or 625KB/s). This is due to the collision-based nature of half-duplex Ethernet. As traffic increases, so do collisions. >>



HALF? i'd shoot the damn card first.

sure collisions will reduce the speed, but the guy is using a SWITCH not a hub.
 
OK guys..I'll try some more and let you the results. I think the cables are the problem...but let's see, I don't want to spend money with no need to to. The switch is unmanaged🙁

vdg
 
OK..I changed the cables to brand new CAT5 gold plated🙂 and the same thing. I am going to change the switch now...my last hope, 'cause the NICs are all different and cannot be part of the problem.

vdg

Edit: actually I saw something interesting: when I forced the NICs to 10/full or 10/half I had no connectivity at all, but the switch was indicating the right speed, any idea why(I tried on 2 win2k comp) ?
 
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