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Problems achieving 1Gbps data throughput on network

Last response: in Networking
July 28, 2009 3:23:41 PM

I have two PC’s linked together both have Gigabit network cards and are linked via a Netgear router with a Gigabit switch. I cannot get the data throughput to go above 25% (250Mbs) I have tried various driver settings and have been in touch with Netgear support what use they were (none) and am still stumped.
Can anyone help me get my network running faster. Details of the PC’s and router are bellow.

Thanks for your help Dave

PC 1
Running windows firewall
Mother Board ASRock 939N68PV-GLAN
Chipset nForce 630A MCP

NVIDIA nForce 10/100/1000 Mbps Ethernet
Driver Nvidia

Driver settings
Flow Control Disabled
Interrupt moderation Disable
Low Power State Link Enabled
Network address Not Present
Priority & VLAN Disabled
Speed/duplex settings Auto Negotiate
WOL Enabled

PC 2
Running Nvidia firewall
Mother Board Asus A8N-SLi Deluxe
Chipset nForce 4

NVIDIA nForce 10/100/1000 Mbps Ethernet
Driver Nvidia

Driver settings
Checksum offload Enable
Flow Control Disabled
Jumbo Frame Payload Size 9000
Low power state link speed Enable
Network address Not Present
Optimise for CPU
Segmentation Offload Enable
Speed/duplex settings Auto Negotiate
Priority & VLAN Disabled
WOL Enabled

NetGear WNR854T RangeMax Next Wireless Router - Gigabit
July 28, 2009 5:02:21 PM

Gigabit has a limit, albeit on paper of 125 megabytes a second (1,000,000,000 /8 = 125,000,000 bytes) . That speed will never never be reached though. Your average hard disk can do a sustained write around 65 megabytes a second, which is roughly half that of the theoretical limit. You also have to take into consideration the the operating system, which you did not mention.
When it all comes down to error correction, hard disk speed, cpu speed, memory speed, and the operating systems efficiency in managing the TCP/IP stack, you are going to find your answer. Windows XP and lower are not optimized for gigabit networks, also I see that you are using socket 939 processors, this means older hardware. So lets say 32-35 megabytes a second.

Simple test, bench mark your hard disks on both machines. See what the lowest disk speed is, this will be your goal for maximum network throughput.

Now create a ram drive on both gigabit optimized machines and copy the data across the network. You will be amazed to find that you should see speeds fairly close to the 100 megabytes a second range, the theoretical limit of gigabit.
Another caveat is Vista and Win7 have network throttling turned on by default, this too can cause lower than expected transfer rates.

I have never been able to have a sustained network transfer on my unmanaged switch fast than my hard disk can read and write. I average a sustained transfer of roughly 60mb a second due to the slow "server" hard disk.

July 29, 2009 11:34:16 PM

Thanks for the answer it is indeed my HDD that is slowing it up. The slowest drive works out to be about 0.21Gbps which is about the network speed I am getting.
Seems I have been striving for speed I just wont achieve.

Cheers Dave