On Wednesday 21 August 2002 08:51 am, Robert Fox wrote: > Could you please shed some light onto this? I have another notebook > (Compaq Armada M700) with an integrated network card (non-pcmcia) and it > works fine at full-duplex.
Quite possibly. This depends on the network card, the driver, the network it's hooked up to, and the options passed to it. > Where is it documented about these problems with hubs and networks? I > have yet to find anything on the Internet about this problem. See link below. > What I fail to understand is - Why does RedHat, Suse and Microsoft > (Win2K and WinXP) all configure the Xircom card with full-duplex turned > on? Also, last I checked - Mandrake 8.2 works fine with full-duplex. Possibly because the driver has been updated, and now defaults to a different setting. If you really want to, you could probably just pass the right option to the driver. I was just pointing out that it doesn't really matter for 99% of all users, and thus not worth the effort to troubleshoot and fix. > Why does the DrakX install also initialize the card with full duplex > during install? DrakX uses a different kernel than the regular distribution (I think). The driver might be different. > I also disagree about not seeing a difference between half/full duplex. > As we all know, duplex is better because both sides can communicate > simultaneously! This is of very dubious benefit for ordinary systems that are not acting as high-volume servers. Few computers can communicate at wire-speed, due to protocol overhead and other factors. While theoretically, the available bandwidth is doubled, it is not so in reality, because clients do not need to send and receive large amounts of data at the same time at wire-speed. Having a USB keyboard doesn't mean you can type on it faster than you can on a PS/2 keyboard, even though it has more bandwidth. It's not the bottleneck. The same thing applies to full duplex vs. half-duplex. The bottleneck is mostly in your computer/protocol, not the wire. Here are a few quotes from one document I found: (http://www.proxim.com/learn/library/guides/gd_halfduplex_ethernet.html) " Performance-wise, Full Duplex operation is beneficial primarily to file servers or similar devices that send and receive traffic simultaneously from several clients." Does your notebook act as a file server? "Shared hubs do not support Full Duplex mode." Therefore, people who use regular hubs instead of switches might have problems if the default is set to full duplex. -- -- Igor
