Realtek NIC update for testing

Sepherosa Ziehau sepherosa at
Tue Nov 7 17:26:52 PST 2017

On Wed, Nov 8, 2017 at 6:05 AM, Lars Schotte <gustopn at> wrote:
> Wait a moment. I have been seeing one issue on this realtek cards,
> reproducible on Linux and FreeBSD.

Ours are different from Linux and FreeBSD one.  And our way of
interrupt throttle in re(4) is unique (openbsd adopted our way).

> The problem was that when you hit a realtek card with gigabit speeds,
> both ways at the same time, for example with NFS, having a pf firewall
> in place, you will get a watchdog timeout.

It works for me on Dfly.  Full line rate, dual side.

> Problems like this do not happen on Intel NICs.

Well, never compare Realtek's stuff w/ Intel's :)

> Some report that problems go away with Realtek official driver (from
> their website), but havent tried that (I solved the problem by buying a
> intel nic).

Dfly's re(4) chip initialization is taken from Realtek's official
site.  They don't have datasheet for new chips, and the initialization
consists large amount of magic values.

> Also surprising was that I tested some old PCI RTL8169SC and they max
> at 150 Mbit/s even though they should (in theory) transfer gigabit.

I won't be surprised.  This 8169SC is really old, and is PCI.  I'd
suggest you to try their PCIe chips (though I am not recommending it),
latest ones have no issue to TX (w/o TSO)/RX 941Mbps for TCP payload;
relative older PCIe one normally can TX (w/o TSO) @800Mbps and RX
@941Mbps for TCP stream.  Given they are targeting desktop/laptop, the
performance is reasonable.

> To me it blows my mind how can someone sell such hw. And ppl like me
> not even noticing until having replaced all switches with gigabit and
> noticing a bottleneck somewhere in the net I did not expect.
> On cheap mainboards sometime they do put in Atheros, you do not see
> that happening there. For me, every realtek nic is a 100Mbit/s nic no
> matter if it is a 100Mbit/s nic or gigabit.

See my test result.  Newer PCIe chips are much better.

> I d like to know your opinions on it. And second I am interested if
> dragonfly has a driver that is somewhat different from FreeBSD's or
> Linux's (they behave the same way).

As I said, it's different.


> Thanks.
> On Tue, 7 Nov 2017 20:37:10 +0100
> Daniel Bilik <ddb at> wrote:
>> On Mon, 6 Nov 2017 22:11:02 +0800
>> Sepherosa Ziehau <sepherosa at> wrote:
>> > For users have re(4):
>> >
>> > ...
>> > Please test it, and let me know the result.
>> Thank you. Tested with...
>> re0 at pci0:3:0:0:       class=0x020000 card=0x81681849 chip=0x816810ec
>> rev=0x11 hdr=0x00 vendor     = 'Realtek Semiconductor Co., Ltd.'
>>     device     = 'RTL8111/8168/8411 PCI Express Gigabit Ethernet
>> Controller'
>> ... works fine, no problems observed.
>> --
>>                                               Dan
> --
>  Lars Schotte
>  Mudroňova 13
> 92101 Piešťany

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