IRC #olimex 2015-04-14

[00:05:31] <lukas2511> feels like 10 write cycles
[00:05:42] <lukas2511> but is probably 11
[15:31:02] <lukas2511> i'm having packet loss on lime2 ethernet on full speed, a lot more than i get on bananapi, is that "normal"?
[15:43:11] <nedko> i think this is expected
[15:43:29] <nedko> a20 cannot saturate gigabit ethernet
[15:43:50] <lukas2511> yea but it is far worse than on my bananapi
[15:46:35] <lukas2511> guess i'll play around with the timing compensation bits, and hope it gets better... or i'll just order a new one and hope that it works better... mh
[15:46:50] <nedko> how do you measure the packet loss?
[15:47:36] <lukas2511> iperf is showing loss itself, also while iperf is running icmp replies ("ping") are dropped as well
[15:47:57] <nedko> iperf in udp mode?
[15:48:04] <nedko> what bandwidth is set?
[15:48:06] <nedko> full?
[15:48:11] <lukas2511> tcp mode, it resent missing packets, so it was slow
[15:48:16] <lukas2511> yes full
[15:48:24] <nedko> you better do this tests in udp mode
[15:48:25] <lukas2511> i'm getting 400-500mbit/s max on lime2
[15:48:31] <lukas2511> 800 with far less packet loss on bananapi
[15:48:34] <lukas2511> same settings
[15:48:57] <nedko> and same software? e.g. tcp stack and tcp stack parameters?
[15:48:59] <lukas2511> also using VPNs (in this case pptp) over the connection is a lot slower on lime2 because all the packets that have to be resent
[15:49:18] <lukas2511> yes, exactly the same system, only bootloader is swapped between boards (but build from same source)
[15:49:47] <nedko> interesting
[15:50:35] <lukas2511> i mean, i'm not happy with the bananapi losing packets as well, but it's "okayish", while the lime2 is horrible in the same setup
[15:50:57] <lukas2511> and i'm really not sure if it's a hardware fault with my board or if it's just "normal"
[15:51:17] <lukas2511> don't know if anybody ever tried running the ethernet at its max capacity
[15:52:25] <nedko> does the bannanapi use the a20 ethernet?
[15:52:44] <lukas2511> yes, both use gmac
[15:53:02] <lukas2511> same kernel module, only some power stuff is different on the bananapi board iirc
[15:54:38] <nedko> maybe ethernet routing is not so good on lime2
[15:56:04] <lukas2511> no idea... i mean... i really would love to use the lime2 in that setup, because it just feels like 1000% better quality... but this problem makes it unusable
[21:12:57] <forkit1> Morning / Afternoon / Midnight. I am trying to use a A20SOM with the mainline kernel, and I would like to know what dtb to use?
[21:21:32] <forkit1> I have a rev B board, but will hopefully buying more and getting rev D's