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Slow gigabit network

Last response: in Networking
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January 11, 2005 5:37:37 AM

Hello all.
After a lot of ebay'ing I'm finally running two dual computers. A desktop dual opteron 244, and server dual athlon mp 2400. I have a netgear switch gs105, the Broadcom NetXtreme Gigabit Ethernet nic on desktop and D-Link DGE-530T Gigabit Ethernet Adapter on server. On server I also have 3ware 9500s raid controller on 66/64 bit pci. Well anyhow I only get like 20 megabytes/s using utility netcps which don't involve the harddrives. I have unplugged all addoncards 3ware included, disabled all bios features(usb, ac97, com ports etc) to avoid IRQ conflicts. Still the same. I have tried to connect the pc's directly without the switch=same result.
So it's not irq, pcibus, driver, processes, weak pc, switch related. What could it be. Running two freshly installed xp eng with sp2 integrated. Oh and using cat5e cables 2 meters long. The cables to the pc's are not grounded but I doubt that to be the cause.
Thankful for any help.

Regards
Loppjack

More about : slow gigabit network

January 11, 2005 6:51:41 AM

20mb/s sounds about right. That is what I average when doing transfers via direct connection or through a gigabit switch. Only in rare instances have I seen transfers over that and only on very high end equipment. The last time I saw a transfer over 20mb/s was between 2 HP Prolient servers w/ onboard intel gigabit nics hooked upto a cisco 3550 gigabit switch. That was around 40-50mb/s or so. I have gotten around 30-40mb/s once at a lan party when me and another guy were hooked up to a dell 24port switch w/ 2 gigabit ports and we both had onboard intel gigabit nics and raid0 raptors.

If you want to try and speed your connection up I'd get rid of that D-Link card, that is probably slowing you down a tad. Get another Broadcom nic for that machine.

<A HREF="http://www.folken.net/myrig.htm" target="_new">My precious...</A>
January 11, 2005 9:01:40 AM

The most I get is 35MB/sec according to sandra. I was very dissappointed.
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January 11, 2005 7:13:40 PM

well since I have also tried to bypass the switch, by using a cat6 cable directly between the 2 pc's, I know for sire that the switch isn't the weak point. I got the same result without the switch. I mean have you ever heard of 2 2ghz+ dual systems connected directly to eachother on gigabit nics in gigabit mode, "only" get 22 megabytes of transfer when harddrives ARE NOT INVOLVED!
This is pure madness. The gigabit concept are a hoax. When there is absolutely no limiting factors, and still only 22megabytes, and people accept it? Well I don't.
January 11, 2005 8:07:50 PM

It's a hell of a lot faster than 10/100 so I'm satisfied :) 
I don't do any sort of major transfers all the time though. You are probably doing video stuff that could use the higher transfer rate arn't you.
I still say you should get rid of that D-Link card, I've never used a D-Link product that wasn't garbage. I know some people swear by the routers and such but I myself have yet to see a D-Link product that didn't suck and break. I'd never even consider them for more industrial purposes like servers or large networks.

<A HREF="http://www.folken.net/myrig.htm" target="_new">My precious...</A>
January 14, 2005 2:11:42 PM

How are you transfering large files without using hard drives? Just curious.

Gigabit networks aren't for increasing your transfer speeds. They're designed for corporate networks to allow more throughput to more computers. Meaning that 100Mb connection can allow 30 connections good bandwidth, but at 60 the bandwidth starts drop. Gigabit allows more connections without the drop in bandwidth. Data can only move so fast over that wire which is your limiting factor. The ratings of the wire means what MHz it runs at which in the end allows more signals to run through it, therefore icreasing the amount of data that can be put onto it - not how much faster it'll travel through it.

Gigabit is perfectly clear that you can achieve the speeds. It just doesn't tell you that's across multiple connections over one wire.:) 

Try hooking up 5 computers and running that test. You'll eventually reach the gigabit connection. The exact same reason you won't see 100Mb in and 100Mb connection.

Riser
January 14, 2005 8:15:50 PM

You would get better performance if your hardware support jumbo frame.
January 20, 2005 12:10:39 PM

Cat5e has a limit of 300Mb/s or 37,5 MB/s. It's very rare that you get this speed since interference, dodgy contacts etc will affect the signal.

With gigabit over fiber it's not hard to reach 100+MBs...

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I want my epitaph to be: "Moved to /dev/null"
January 21, 2005 6:58:26 PM

"Cat5e has a limit of 300Mb/s or 37,5 MB/s."

Not sure where your getting this but that is not correct.
!