----- Original Message ----
From: John R Pierce pierce@hogranch.com To: centos@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