As far as i know there are 3 possibility's for onboard lan chip: intel , broadcom and realtek.
what is best and what is no good, or does it not matter?
What matters is what other devices you try to install; conflicts can occur with any build. I haven't used an Intel lan for a long time, but the broadcom and realtek work fine. I had problems with the sata controller on some ssd's, but not the lan chipset.
As far as i know there are 3 possibility's for onboard lan chip: intel , broadcom and realtek.
what is best and what is no good, or does it not matter?
thanks for any reply
You'll find Intel and Broadcom mainly on servers (though Intel can sometimes be found on a few high-end desktop motherboards). The motherboard type often dictates the LAN controller: Mostly Intel (and sometimes Broadcom) for servers and workstations; Realtek or Marvell for less expensive motherboards.
You shouldn't really worry yourself about the lan chip on your Mobo. You'll probably never have any problem whatever the brand.
Speed is probably the only factor you should focus on (10/100/1000)
Other factors such as RAM support, PCI/PCIE ports to support your hardware and uses you may have for the machine like a good sound card etc. are more important issues you should think about.
The only issue I've encountered is that Realtek doesn't tend to be the best for streaming media from a home server to a HTPC. Apart from that, I've had no problem with them.