eric@zen.maths.uts.edu.au (Eric Lindsay) (05/03/91)
I recently installed a lab of 20 386SX PCs, running without hard disks, booting from boot roms and a Novell 386 server, for student use. Some (most?) of these run very slow over the thin ethernet (25 seconds to do a DIR of \public, vs the 5 seconds I'd expect). The ethernet cards used are a Taiwanese Accton Technology Corporation Acc-10 Ethercoax-8WB, with a local boot rom. These are an imitation of the Western Digital WD8003EBT. My slow problems seem worse when machines are cabled close together, and somewhat better when I use 4 or 5 meter cables (but all 20 machines are in one room). The speed is much slower on some machines when some other nearby machines are switched on (the slowdown occurs on power-up of the adjacent machines, not when the ethernet cards starts booting from server). I have tried replacing VGA cards with Hercules clones. Changed the card settings from int 2, IO 2a0, ram D0000 rom D8000 to int 2, IO 280, ram D0000, rom D8000. Booted from floppy instead of boot roms. Replaced the Acme Electronics BNC connectors with DEC ones on some cables. Reduced the network size to three machines. Booted from a Novell 2.15 server instead of the Novell 3.10. Changed the boot image files. Tried the ethernet cards in some old XT machines. The speed reduction varies according to the card, the PC it is in, and the length of cable between it and other machines. Can't really isolate any common factors, although I still could have bad T connectors, or possibly my Harland cable isn't up to it. Found a few old style WD8003EBT cards, which do not show the problem so far, whether in SX or in XT. This leaves me thinking the problem is the cards. So far I have not been able to SHGEN a workstation shell using the driver supplied with the Accton card (it kills SHGEN), so I used the WD8003 ones. The driver supplied for the server worked fine however. Has anyone else used these cards? Have you found (and solved) similar problems? Is there something obvious to network people that I am overlooking (I'm not a PC or a Novell user by choice). Can anyone tell me where it is possible to obtain the old style WD8003EBT ethernet cards (the ones with jumper configuration, not the software configured later model)? Eric Lindsay, School of Mathematical Sciences, University of Technology, Sydney, NSW, Australia eric@zen.maths.uts.edu.au -- eric@utsmaths.maths.uts.edu.au Eric Lindsay, Sch of Maths, Uni of Tech Don't take life too seriously. It is only temporary.