Why is my 100Mbps LAN so slow??
10 July 2002, 09:36 AM
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We debated this very topic this week on a mailing list.
Somebody offered that full duplex turned off the CSMA/CD hardware which causes problem when running peer-to-peer and not via a switch.
Going to half duplex speeded up copying (ask MarkO - he was doing it).
[Edited by ChrisB - 10/7/2002 9:37:25 AM]
Somebody offered that full duplex turned off the CSMA/CD hardware which causes problem when running peer-to-peer and not via a switch.
Going to half duplex speeded up copying (ask MarkO - he was doing it).
[Edited by ChrisB - 10/7/2002 9:37:25 AM]
10 July 2002, 09:43 AM
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So long as both NIC implement FDX properly there is absolutely no technical reason it cant work. Some cheap nics don't.
There was a bug in NT4 which meant FDX was implemented incorrectly at the layer between NIC Driver and OS. FDX (via a switch or peer-to-peer) was therefore slower than HDX.
Spent a long time testing NIC performance a few years back for a high street bank. All the server techies kept setting the NICs to FDX then whining when performance was sh*te. More recently I saw a case where a team were testing disasetr recovery with NT4 servers restoring over a network. Again performance was cr*p with FDX. Theres a knowledge base article somewhere.
Bizarrely I've often founf that the more expensive the kit the worse auto-negotiate is. Point a £30K compaq server at a £30K cisco
switch and it will more than likey screw up. Point a £10 B&Q Nic at a netgear hub and chances are it will be fine. Go figure.
Deano
[Edited by dsmith - 10/7/2002 9:47:09 AM]
There was a bug in NT4 which meant FDX was implemented incorrectly at the layer between NIC Driver and OS. FDX (via a switch or peer-to-peer) was therefore slower than HDX.
Spent a long time testing NIC performance a few years back for a high street bank. All the server techies kept setting the NICs to FDX then whining when performance was sh*te. More recently I saw a case where a team were testing disasetr recovery with NT4 servers restoring over a network. Again performance was cr*p with FDX. Theres a knowledge base article somewhere.
Bizarrely I've often founf that the more expensive the kit the worse auto-negotiate is. Point a £30K compaq server at a £30K cisco
switch and it will more than likey screw up. Point a £10 B&Q Nic at a netgear hub and chances are it will be fine. Go figure.
Deano
[Edited by dsmith - 10/7/2002 9:47:09 AM]
06 October 2002, 06:57 PM
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I assume you have checked that both machines are connected at 100mbit (full duplex also)
Only other thing is that windows copy is dreadful
Try copying the file using DOS copy and see if it is faster..
Only other thing is that windows copy is dreadful
Try copying the file using DOS copy and see if it is faster..
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07 October 2002, 07:34 AM
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Full-Duplex is designed for any Connection between two devices on non-shared media. Could be PC-Switch or PC-PC via X-over or switch-switch.
So long as both ends are set there wouldnt be a problem.
So long as both ends are set there wouldnt be a problem.
07 October 2002, 09:42 AM
#16
Interestingly (or not) my sister had this problem when I was over in Ireland the other day.
She had the added complication of having a 10mbs card & a 10/100mbs card. Pi$$ing about for ages downloading drivers etc
In the end, found an old ISA BNC card & lobbed that in as the 10mbs card was a combo - luckily she still had some BNC cable & terminators
She had the added complication of having a 10mbs card & a 10/100mbs card. Pi$$ing about for ages downloading drivers etc
In the end, found an old ISA BNC card & lobbed that in as the 10mbs card was a combo - luckily she still had some BNC cable & terminators
07 October 2002, 09:57 AM
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More than likely its dodgy home-grown software screwing the drivers up
All our SUNs talking to Cat65K always **** it up unless hard-set. Cisco Routers talking to Cats cant manage it either. I really wonder where the R&D budgets go sometimes.
Deano
All our SUNs talking to Cat65K always **** it up unless hard-set. Cisco Routers talking to Cats cant manage it either. I really wonder where the R&D budgets go sometimes.
Deano
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