Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.


jim.cox

219 posts

Master Geek


#16627 19-Oct-2007 13:51
Send private message

Kia ora

We've just moved to a new office, and we upgraded our network to Cat5 TP

I've set ALL the machines to 100Mbits full duplex - and they seem happy at that

But I'm not getting anything like the network throughput I expected.

Doing some big file copies afterhours (so minimal network contention) the best throughput I can get is about 9.3Mbits, and mostly its down around 3 or 4

Watching the server it appears to be spending most of its time in the system idle process. And the network loading is low.

Watching the timing of the packets I see them come in short bursts with long pauses of nothing in between.

I'm wondering if the (cheap) ethernet switch might be the cause.

It looks to me like the switch might be squirting the data at 100 and then waiting long enough to have sent the data at 10, effectively slowng the whole shooting match down to 10

How do 10/100 switches handle the different data rates ?





=mjc=
.


Create new topic
BartManGeek
187 posts

Master Geek


  #92054 23-Oct-2007 12:30
Send private message

Have you tried a crossover cable connected directly between PC and server? This will eliminate the switch as a problem.

Let us know how you go,
Bart.

Affiliate link
 
 
 

Affiliate link: Trade NZ and US shares and funds with Sharesies.
pando
235 posts

Master Geek


  #92058 23-Oct-2007 13:26
Send private message

Was my understanding that switches prefer autonegotiation.

Forcibly setting the nic's in each machine to use the top setting can have a detrimental effect on overall performance, you should leave them on the autonegotiate.

Next you should then get a TCP optimizer program, if you're using windows 2000/XP or earlier the OS is preconfigured for a 10Mbps network not a 100Mbps one.

cyril7
8756 posts

Uber Geek

ID Verified
Trusted
Subscriber

  #92062 23-Oct-2007 14:11
Send private message

Agreed definitely let the NICs autonegotiate, however that said if they are not doing 100 duplex then there is either a cable problem or the NICs or switch are substandard.

Even the cheapest of switches use commonly available switch chip sets that are also used in better priced products. Realtek chipsets are the most common Ive found at the low end of the market, and these work very well, you should readily be able to achieve 70-80Mb/s through put of TCP traffic. I use wsttcp.exe as a simple throughput check. Remember that TCP will only achieve around 80% full throughput due to TCP overheads.

As others have suggested, get a crossover cable (although a straight through will work most autoconfiging NICs) and check the throughput with local cables and no switch, then add cable and switch back into the mix to see whats causeing the issue.

Cyril



Fraktul
836 posts

Ultimate Geek

Trusted

  #92097 23-Oct-2007 18:14
Send private message

Autonegoiate does not always work best, sometime it flaps or otherwise results in corruped frames.

If you have a decent switch and NICs they will report any CRC errors allowing you to rule out any speedmismatch, cabling issues or other problems at layer 1.

jim.cox

219 posts

Master Geek


  #92183 24-Oct-2007 09:04
Send private message

Fraktul: Autonegoiate does not always work best, sometime it flaps or otherwise results in corruped frames.

If you have a decent switch and NICs they will report any CRC errors allowing you to rule out any speedmismatch, cabling issues or other problems at layer 1.


As I say, I'm not seeing any error messages

Just the system sitting mostly idle, the network utilisation well  under 25% and the throughput around 3% :(

But thankx for the hints guys. I'm planning on some afterhours testing with a a spare machine directly connected. That should confirm whether it is the switch

Cheers

Jim

=mjc=
.





=mjc=
.


kdn

kdn
198 posts

Master Geek


  #92201 24-Oct-2007 12:15
Send private message

generally when one device is set to auto and the other is strapped to 100/full the link will run at 100mb half duplex.. if its not a managed switch that you can set the ports to run at 100 full on then change the pc back to auto auto.

Unfortunately there is no easy way to check what duplex its running at from the pc side, you can foudn out the manufacturer of the network card you are using andf see if they have a downloadable tool to tell you.

But in my experience (which is quite a lot with switches) setting oen side as static and one as auto neg usually results in half duplex which is why you ar egettign such poor performance, one way is also a cross over between the two pc's and see what sort of speed you get then.

Flamer.

mcraenz
1111 posts

Uber Geek


  #95336 15-Nov-2007 12:44
Send private message

Tha's my understanding as well, when one side is set to auto and the other is satic then the autonegotation will fail and it will default to 100/half






 

Help me build a new way of doing politics in Aotearoa New Zealand

 

 

 


Create new topic





News and reviews »

Samsung Introducing Galaxy Z Flip4 and Galaxy Z Fold4
Posted 11-Aug-2022 01:00


Samsung Unveils Health Innovations with Galaxy Watch5 and Galaxy Watch5 Pro
Posted 11-Aug-2022 01:00


Google Bringing First Cloud Region to Aotearoa New Zealand
Posted 10-Aug-2022 08:51


ANZ To Move to FIS Modern Banking Platform
Posted 10-Aug-2022 08:28


GoPro Hero10 Black Review
Posted 8-Aug-2022 17:41


Amazon to Acquire iRobot
Posted 6-Aug-2022 11:41


Samsung x LIFE Picture Collection Brings Iconic Moments in History to The Frame
Posted 4-Aug-2022 17:04


Norton Consumer Cyber Safety Pulse Report: Phishing for New Bait on Social Media
Posted 4-Aug-2022 16:50


Microsoft Announces New Solutions for Threat Intelligence and Attack Surface Management
Posted 3-Aug-2022 21:54


Seagate Addresses Hyperscale Workloads with Enterprise-Class Nytro SSDs
Posted 3-Aug-2022 21:50


Visa Launching Eco-friendly Payment Solutions in New Zealand
Posted 3-Aug-2022 21:48


NCR Delivers Services to Run Bank of New Zealand ATM Network
Posted 30-Jul-2022 11:06


New HP Portfolio Supports New Era of Hybrid Work
Posted 28-Jul-2022 17:14


Harman Kardon Launches Citation MultiBeam 1100 Soundbar
Posted 28-Jul-2022 17:10


Nanogirl Labs Launches Creator Project
Posted 28-Jul-2022 17:05









Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.







Backblaze unlimited backup