Subject: Re: BCM5704 performance questions.

From: Ben Greear <[email-masked]>
Date: Fri, 10 Jun 2005 15:35:35 -0700

Michael Chan wrote:
> On Fri, 2005-06-10 at 14:09 -0700, Ben Greear wrote:

>>I commented out the code and ran the pktgen test again.  It may be a small
>>bit better, but not much:  770Mbps in one direction, 750Mbps in the other.
>>

> The latest tg3 driver will print out the dma_rwctrl at probe time. Can
> you check the value to make sure ONE_DMA is disabled? Bit 14 sets
> ONE_DMA.

I don't see any printout in /var/log/messages that looks like it
relates to the dma_rwctrl.  I'm using the driver in 2.6.11..maybe
it is not recent enough to print this information out?

>>Have you done any tests with 2 tg3 NICs in a single machine to see if they
>>can run at or near line speed (full duplex)?
>>

> Yes, we have years ago but not with the tg3 driver. We set up the 5704
> to bridge (or route, I don't remember) one port to the other. It cannot
> bridge at line-rate with the ONE_DMA workaround enabled.

Ok.  Do you have other chipsets/NICs that can handle faster GigE speeds?

If you'd like to send me some multi-port NICs to play with I'll be happy
to report my findings :)

Thanks,
Ben

-- 
Ben Greear <[email-masked]>
Candela Technologies Inc  http://www.candelatech.com