[CentOS] Problems with motherboard support? INTEL DP43BF
Fernando Gleiser
fergleiser at yahoo.com
Tue Dec 28 22:28:24 UTC 2010
----- Original Message ----
> From: John R Pierce <pierce at hogranch.com>
> To: centos at centos.org
> Sent: Tue, December 28, 2010 2:59:09 AM
> Subject: Re: [CentOS] Problems with motherboard support? INTEL DP43BF
>
> On 12/27/10 9:09 PM, robert mena wrote:
> > Regular realtek fast ethernet.
>
> IMNSHO, realtek are pretty close to junk grade NICs. they have far too
> many variations with far too many weird bugs when used for any more than
> single user desktop kind of systems.
>
rl nics are toy nics. I wouldn't use them on production servers unless I have no
choice
For some reasons, see this, textually from FreeBSD's 5.4 if_rl.c:
/*
* The RealTek 8139 PCI NIC redefines the meaning of 'low end.' This is
* probably the worst PCI ethernet controller ever made, with the possible
* exception of the FEAST chip made by SMC. The 8139 supports bus-master
* DMA, but it has a terrible interface that nullifies any performance
* gains that bus-master DMA usually offers.
*
* For transmission, the chip offers a series of four TX descriptor
* registers. Each transmit frame must be in a contiguous buffer, aligned
* on a longword (32-bit) boundary. This means we almost always have to
* do mbuf copies in order to transmit a frame, except in the unlikely
* case where a) the packet fits into a single mbuf, and b) the packet
* is 32-bit aligned within the mbuf's data area. The presence of only
* four descriptor registers means that we can never have more than four
* packets queued for transmission at any one time.
*
* Reception is not much better. The driver has to allocate a single large
* buffer area (up to 64K in size) into which the chip will DMA received
* frames. Because we don't know where within this region received packets
* will begin or end, we have no choice but to copy data from the buffer
* area into mbufs in order to pass the packets up to the higher protocol
* levels.
*
sadly, things hadn't improved since then
Fer
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