Trying to get 1000MB speeds

[thekeymaker]

Hi all!

I have been having some trouble with my home network and maybe someone could help me out!

Here is my situation. First of all I have two Gentoo Linux computers. These computer both have Ethernet ports that support 1000MB/s speeds. Here is the ethtool report for both of the cards.

Computer 1:

Settings for eth1:

	Supported ports: [ MII ]

	Supported link modes:   10baseT/Half 10baseT/Full 

	                        100baseT/Half 100baseT/Full 

	                        1000baseT/Full 

	Supports auto-negotiation: Yes

	Advertised link modes:  10baseT/Half 10baseT/Full 

	                        100baseT/Half 100baseT/Full 

	                        1000baseT/Full 

	Advertised auto-negotiation: Yes

	Speed: 1000Mb/s

	Duplex: Full

	Port: MII

	PHYAD: 1

	Transceiver: external

	Auto-negotiation: on

	Supports Wake-on: g

	Wake-on: d

	Link detected: yes

Computer 2:

Settings for eth1:

	Supported ports: [ TP MII ]

	Supported link modes:   10baseT/Half 10baseT/Full 

	                        100baseT/Half 100baseT/Full 

	                        1000baseT/Half 1000baseT/Full 

	Supports auto-negotiation: Yes

	Advertised link modes:  10baseT/Half 10baseT/Full 

	                        100baseT/Half 100baseT/Full 

	                        1000baseT/Half 1000baseT/Full 

	Advertised auto-negotiation: Yes

	Speed: 1000Mb/s

	Duplex: Full

	Port: MII

	PHYAD: 0

	Transceiver: internal

	Auto-negotiation: on

	Supports Wake-on: pumbg

	Wake-on: g

	Current message level: 0x00000033 (51)

	Link detected: yes

I have a Cat6 cable connecting the two computers together for direct file backup. Now when I run iperf to check my speeds, I get the following:

------------------------------------------------------------

Client connecting to 192.168.1.2, TCP port 5001

TCP window size: 16.0 KByte (default)

------------------------------------------------------------

[  3] local 192.168.1.1 port 51659 connected with 192.168.1.2 port 5001

[ ID] Interval       Transfer     Bandwidth

[  3]  0.0-10.0 sec  76.5 MBytes  64.2 Mbits/sec

My question is why is this so slow and how do I get my speeds closer to 1000Mb/s?

Any help is very much appreciated!

[Irithori]

You directly connected them, so there is no switch involved?

With the switch out of the way, are the PCs fast enough to handel GBit wirespeed?
But most likely: What kind of NICs do you have?
For example: Some cheap realtek wont do it, imho.

[thekeymaker]

Yes that is correct!
I probably should have mentioned that...

They are connected directly together using a Cat6 crossover cable.

No switch or hub used....

[Irithori]

ok, but how fast are your PCs and
most of all: what brand are your network cards?

[druidmatrix]

What is the filesize you are using? What are your CPU and memory loads on the individual machines while the transfer is happening? Is it swapping while trying to read/write before/after transfer? If so, you are now getting into disk access issues as well, and so your speed measurement would not be truly representative.

[thekeymaker]

Computer 1:

AMD Athlon(tm) 64 X2 Dual Core Processor 6000+
ASUS M2N-SLI Deluxe AM2 NVIDIA nForce

6G of ram
On-board motherboard networking.
I'm no sure what the type it is....

-----------------------------------------------------------------------------------------------------------------

Computer 2 (the old computer):
AMD Athlon(tm) XP 2000+

256M of ram

Rosewill RC-400 10/ 100/ 1000Mbps Networking LAN Card
Sorry I can't post links yet on the forum...


--------------------------------------------------------------------------------------------------------

When running both of the test, both PC's were experience little to no cpu/memory/swap usage.
By test I mean running iperf.

[thekeymaker]

when I do a lspci for the on-board network it comes up as this... if that helps at all???

00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a2)
00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a2)

[thekeymaker]

Oh this may be part of my problem...

I decided to do a scp of a movie file I had and then looked at the performance of both my machines.

First he is the scp output:
Move_Name.mkv 41% 3586MB 15.4 MB/s 4:00 ETA


Here might be the problem:
The older pc (Computer 2)

Stats during transfer:
CPU 100%

The memory usage ans swap are still both very low but this hi cpu usage might be the problem....

What do you guys think???

[Irithori]

Cant say anything about the Rosewill, as I dont know them.

But the nvidias dont have a good reputation in my book.
Can you get a pair of intel GBit Pro/1000 GT, even just for a comparison?
Most probably the throughput will be close to wirespeed with them.

Also, the older PC might have a hard time to keep up.
You might get wirespeed with a pure throughput test, but for scp the CPU has to work hard.

[druidmatrix]

Yes, the smaller PC is not able to handle the load CPU wise.