vr speed issues

[Charles Sprickman]

On Fri, 1 Dec 2006, Mark Kirkwood wrote:

> Mark Kirkwood wrote:
>> Charles Sprickman wrote:
>> 
>>> I also did a little more digging and noticed that once I start pinging 
>>> from one of these hosts using large packet sizes, I get about 50-60% 
>>> packet loss (ie: ping -s 1500 other.vr0.host).  If I ping something with a 
>>> decent card, I get about 30-50% packet loss.  There's no packet loss with 
>>> the default packet size.
>>> 
>>> Anyone else with some vr cards feel like checking this out?
>>> 
>> 
>> I've got a VIA Rhine III card that I can dig out and put in if the data 
>> would be of any use/interest etc - FWIW I seem to recall being able to get 
>> reasonably close to wire speed when I was using it.
>> 
>
> I plugged in the card today, and seem to get pretty reasonable performance 
> (8-10MB/s for scp - see attached). The two boxes are plugged into a Linksys 
> router via store made cat5 or cat6 cables. The second box has an Intel PRO 
> 100 (fxp) adapter.

Interesting.  I've had the vr hosts going through three different 
switches, patch cables, the in-house cabling, and the issue remains the 
same.  I'd love to just replace a cable and be done with it, but that 
doesn't seem to be the issue.  I can also eliminate it by just switching 
out cards...  so I don't really suspect I've got a whole load of bad 
cables.

> Removing the vr card and going back to fxp everywhere seems to provide better 
> performance (e.g. get 9MB/s in the last test), but the vr performance is 
> acceptable (maybe your router clashes with your card?).

Mine borders on unusable.  The packet loss really slows down and stalls 
TCP connections.

I noticed you have a newer revision of the Via card:

# pciconf -lv
vr0 at pci0:9:0:   class=0x020000 card=0x14031186 chip=0x31061106 rev=0x86
hdr=0x00
     vendor   = 'VIA Technologies Inc'
     device   = 'VT6105M/LOM Rhine III PCI Fast Ethernet Controller'
     class    = network
     subclass = ethernet

This is what I'm dealing with:

hostb6 at pci0:17:7:       class=0x060000 card=0x287e1106 chip=0x287e1106 
rev=0x00 hdr=0x00
     vendor   = 'VIA Technologies Inc'
     class    = bridge
     subclass = HOST-PCI
vr0 at pci0:18:0:  class=0x020000 card=0x80a71043 chip=0x30651106 rev=0x7c 
hdr=0x00    vendor   = 'VIA Technologies Inc'
     device   = 'VT6102 Rhine II PCI Fast Ethernet Controller'
     class    = network
     subclass = ethernet

Maybe I'll just round up as much info as I can at my next visit, grab some 
tcpdumps of the loss from both ends and do a send-pr and hope for the 
best.  I can get along with replacing the cards, but they seem to be 
really common these days - basically any cheap system with a Via chipset 
and onboard ethernet will be using some variation on this controller.

Charles

>
> Cheers
>
> Mark
>
>