[vpn-help] Windows 7 32bit poor performance and timeouts

Matthew Grooms mgrooms at shrew.net
Mon Oct 11 14:46:24 CDT 2010


On 10/11/2010 12:45 PM, Bernd Muschke wrote:
>   Hi Matthew,
>
> LSO was a good hint, thank you.
>
> Today we did some tests with our "bad" adapters all with current drivers.
>
> Intel:
>      82566DM-2 and PRO/1000 MT are only ok when you switch off LSO
>
> Broadcom:
>      57xx does not provide such a switch, we switched off every other
> available option one at a time without success
>
>
> Do you have the ability to test such an adapter? You can see immediately
> if it is ok or not when you simply copy a 20MB file with Winscp or any
> other client which shows you transfer rates. The rates are very low and
> change all the time and might even drop completely.
>
> While you don't transfer files you might not even notice that there is a
> problem. We used our "bad" adpaters all day long with Putty and thought
> that everything was ok.
>
> So now we know that we can add Intel cards to our Broadcom desktops and
> switch off LSO to bypass our problem but this is not the best solution.....
>

Hi Bernd,

I just ordered both a PCI-X and a PCI-e version of the Intel PRO/1000 MT 
adapters. After a bit of googling, it would appear that Broadcom has a 
tool called BACS that can be used to disable the LSO support feature of 
Netxtreme cards. I'm not sure if this is the right version for your 
particular adapter. The version.txt file says it supports Vista but not 
Windows 7. I would give it a try anyway as Vista and Windows 7 are very 
similar OS's ...

http://www.broadcom.com/support/ethernet_nic/netxtremeii.php

I'm interested in fixing this issue. But I would feel more motivated to 
make this a high priority if you can verify that the client also works 
well with a Netxtreme adapter that has the LSO feature disabled. If so, 
fixing the Intel card LSO issue should also have a high probability of 
resolving your Broadcom Netxtreme issue as well.

Thanks,

-Matthew



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