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Re: [microblaze-uclinux] Error when processing wget

Hi, John

sorry for my late reply.

On 9/15/06, John Williams <jwilliams@xxxxxxxxxxxxxx> wrote:

Hi Qichen,

Qichen Huang wrote:

> Here is the result of my measurement:
> using 100MHz uclinux/microblaze (ML403, virtex4):
> 10mbps, top speed 843KB/s, average speed to download a file (2 or 10
> Mbyte) varies from 330KB/s to 775KB/s.
> 100mbps, top speed 820KB/s, ave. speed varies from 294KB/s to 682KB/s.

That doesn't sound right.  Are you using the SGDMA or FIFO mode for the ethernet
MAC?


I just used the default opb emac. It's not SGDMA mode.



The block size used in the transfer can have a huge impact.  I've not
experimented with wget, but I know with tftp using larger block sizes gave up to
10X bandwidth improvements.



When using wget to download http packets, the max. block size is 1514
bytes. But it varies.


Also, have you confirmed it's not some local network issue?  I've had problems
in the past with embedded systems sitting on corporate networks, being hammered
by broadcast packets.

The cleanest way to test this stuff is to put a 2nd network card in your PC,
hang a 100mbit switch off that, and put your embedded systems off that switch.
 With consumer networking gear so cheap it is a small price to pay for
predictability in the lab.


I have no 100mbit switch. I'm using a crossover cable. The ethernet
speed of the PC networkcard is fixed to 10 or 100mb.
I have also tested the PPC on the virtex running under linuxppc,
configured with the same opb ethernet mac. The result is much better
and seems more stable. For ppc at 100MHz, the average download speed
is around 1600 KB/s at 100mbps, and 850 KB/s at 10mbps.

I doubt, if there's problem within uClinux or MicroBlaze.

regards,
Qichen



Regards,

John

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