slow network xfers

[songokussm]

my bro just got verzion's fiber at home installed today. I went over to help the setup and well to play on his uber fast net. his line is 15/2. he has 3 computers in his house 5 if you count end terminals. they all push the full speed of the line except for one. Ive tried several, at least 5 different NIC's in the system. and it will only hit 1.1-1.2 up (down is fine) while the others hit 1.9-2.1. am i to assume its the mb?

i should state that this is over the internet. the xfers over the lan using this computer are normal.

 

[spidey07]

What are the speeds on the LAN? That could rule out cabling/duplex problems.

Apart from that my guess would be TCP/IP tweaking/settings. You really should modify these on a broadband connection.

 

[InlineFive]

Originally posted by: spidey07
What are the speeds on the LAN? That could rule out cabling/duplex problems.

Apart from that my guess would be TCP/IP tweaking/settings. You really should modify these on a broadband connection.

Wouldn't changing those on a per PC basis also mess with the LAN performance?

 

[spidey07]

Originally posted by: InlineFive
Wouldn't changing those on a per PC basis also mess with the LAN performance?

No.

Broadband is what you call a high bandwidth, high latency network. A lan is a high bandwidth, low latency network.

TCP's algorithym is pretty good for the LAN, not so much for broadband. On a lan and even on broadband packet loss is pretty much not existent. So tweaking TCP some should not affect LAN performance. The biggest thing comes from the TCP window and window scaling. If you want to have some fun sniff some TCP transfers....you'll see what is really going on and how important the window and timers are.

 

[songokussm]

but again, thats incorrect. because 1 out of 5 is not working correctly. if it were tcp/ip settings the whole lan would have an issue together not just one machine.

 

[spidey07]

Originally posted by: songokussm
but again, thats incorrect. because 1 out of 5 is not working correctly. if it were tcp/ip settings the whole lan would have an issue together not just one machine.

false.

tcp parameters are node dependant. Just check them. It's a tcp/ip stack thing, that is software/configuration running on the node.

 

[bsobel]

Originally posted by: songokussm
my bro just got verzion's fiber at home installed today. I went over to help the setup and well to play on his uber fast net. his line is 15/2. he has 3 computers in his house 5 if you count end terminals. they all push the full speed of the line except for one. Ive tried several, at least 5 different NIC's in the system. and it will only hit 1.1-1.2 up (down is fine) while the others hit 1.9-2.1. am i to assume its the mb?

i should state that this is over the internet. the xfers over the lan using this computer are normal.

Is this box older/slower? If so, see if one of those nics lets you offload anything (like crc calcs), might just be taxing the cpu a bit more than the other boxes and showing up as a 33% decline in thruput.

 

[InlineFive]

Originally posted by: bsobel

Originally posted by: songokussm
my bro just got verzion's fiber at home installed today. I went over to help the setup and well to play on his uber fast net. his line is 15/2. he has 3 computers in his house 5 if you count end terminals. they all push the full speed of the line except for one. Ive tried several, at least 5 different NIC's in the system. and it will only hit 1.1-1.2 up (down is fine) while the others hit 1.9-2.1. am i to assume its the mb?

i should state that this is over the internet. the xfers over the lan using this computer are normal.

Is this box older/slower? If so, see if one of those nics lets you offload anything (like crc calcs), might just be taxing the cpu a bit more than the other boxes and showing up as a 33% decline in thruput.

In this situation I really doubt it, at 100Mbit speeds most of my boxes can sustain about 8-9MBs. So this shouldn't be a factor for a 15Mbit connection.

 

[bsobel]

In this situation I really doubt it, at 100Mbit speeds most of my boxes can sustain about 8-9MBs. So this shouldn't be a factor for a 15Mbit connection.

Well, thats why I asked how old the box is. Not putting a lot of faith in the answer, but its a place to look, I've seen it before.