Network card is very slow

[omber]

Ahoy,

My PC is connected to a gigabit switch, which connects to my gigabit router. My storage server is connected to the router. Basically the entire network is gigabit.

Issue: transfer to/from storage server is in in range of ~18 MB/s.

The card is def negotiating Gigabit rates (100 mbps = 12.5 MB/s max).

I have connected my laptop to the same switch as the PC, it can do easily over 70 MB/s to/from server.

I have tried different cable on the PC end; no difference.

I dual boot Win 7 / Ubuntu 14.04 - the issue persists regardless of OS.

System:

i5 3750k @ 4.4
16GB RAM
Gigabyte Z77X-UD3H

I wonder if the board's bus is overloaded as it has two USB 3.0 controllers and I think 3 or 2 storage controllers. If I am transferring things to server and then copy a file between disks on the PC at the same time, the system stops responding for a few seconds.

Im out of ideas - does anyone have a suggestion?

 

[mindbomb]

if at least one of the devices were working at usb 2.0 speeds, that would explain everything.

 

[JonathanYoung]

Something similar happened to me and it was indeed the PCI bus that was the culprit (I tried multiple PCI gigabit cards). When I switched to a PCI-Express card, transfer speeds returned to normal. Perhaps you might want to try the same thing.

 

[RadiclDreamer]

Who is the manuf?

 

[omber]

Regarding manufacturer: the chip on the onboard NIC is Qualcomm Atheros ETHOS AR8151 - I have not been able to find anything about issues with this.

I do have SLI video cards so I wonder if that is not helping. I think I have PCI-E NIC kicking around though so I will try that suggestion.