Reply To: Poor Ethernet performance (AR8035)

[andyolivares]

Hi Erik:

I did the test with my GbE adapter on my home network and same results as the office: poor performance, very slow, almost unusable.

Further testing with “ethtool”, I forced the connection to 100Mbps as follows (still with the GbE adapter):

[ 1281.435683] cpsw 4a100000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 1281.435788] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

Did a few tests, and it worked great just like if I had connected the board to a 100Mbps adapter.

I really think this has something to do with GbE but not sure how. Maybe, as you suggested, my cable has an important role. I’m testing with a cable almost identical to this one: https://www.ebay.com/itm/AWM-E212689-STYLE-2854-32-AWG-30V-2-FEET-CAT-5E-B0816F281J-CABLE-BRAND-NEW-/202639361149 (except mine is black, but has same markings on the cable: AWM E212689 STYLE 2854 80°C 30V CABLE).

Anyway, cabling at office allows 1000Mbps speeds with my USB GbE adapter, at least with my laptop PC, with no problems. Connecting that same cable to my test board produces poor results with some kernel panics from time to time, as stated before.

Maybe USB GbE is more forgiving to link issues than the AR8035 chipset/driver. I don’t really know. Do you think my board’s Ethernet connector choice may have something to do with it (Molex 93626-3508)? As you said… there are not apparent routing problems or board design issues.

Next test will be to connect the GbE USB-to-Ethernet directly to the USB host on my test board and see if the network connection works at full 1000Mbps speed directly connected to my office network.

Will keep you posted. Thank you!

Andy