Re: ppc405ex + gigabit ethernet

[Lada Podivin <lada.podivin@gmail.com>]

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Thank you for your reply!
Yes, I agree the CPU is the bottleneck. But I have performed more tests with
the netperf tool and results seem strange to me. If I send 800 B of data,
the resulting speed is aproximately 100 Kb/s. On the other hand, If I try to
send 32KB chunk of data with jumbo frames turned on, resulting speed is
about 600 Kb/s (300-400 without jumbo frames). My ppc405ex runs at 600 MHz.

So it seems that it is definetely better idea to call sendto() less
frequently with bigger amounts of data, than to call it more often with
smaler amounts. Is it because smaller data means more frequent user
space/kernel space switching? Or is it network related issue?

Thanks!

Best,
Lada

2009/7/1 LiuMing <eemingliu@hotmail.com>

>  Hi,
> According to our experience on PPC405 + Gigabit Enet, your result is
> already very reasonable. For UDP transmission, it can be around 400 Kb/s
> because of the CPU bottleneck (in our case 300 MHz ppc405). If you want
> to further improve it, a faster CPU is needed to process the TCP/IP stack,
> or you may buy commercial TCP/IP stack rather than using the free Linux one.
>
>
> BR
> Ming
>
> ------------------------------
> Date: Tue, 30 Jun 2009 15:58:53 +0200
> Subject: ppc405ex + gigabit ethernet
> From: lada.podivin@gmail.com
> To: linuxppc-dev@ozlabs.org
>
>
> Hi,
>
> I benchmarked performance of my network, which contains ppc405EX (Kilauea
> board, kernel 2.6.30 from Denx) connected with a linux desktop via gigabit
> ethernet. I used the netperf tool:
>
> netperf -t UDP_STREAM -H 192.168.1.1 -- -m 32768
>
> So I was sending UDP packets to the desktop. The resulting speed was about
> 370 Kb/s. I tried to send the packets to several different computers - with
> the same result. So the ppc board is the bottleneck in this case.
>
> Is there any possibility to improve the gigabit capabilities of the
> ppc405EX? Is there anyone who achieved a better performance with ppc4xx
> boards?
>
> Thanks!
>
> Best,
> Lada Podivin
>
>
> ------------------------------
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