Cyclone 3x905b Corruption/problems
Thu Mar 18 11:46:09 1999
On Thu, 18 Mar 1999, Michael Thompson wrote:
> I have a DEC 486-66 box running redhat 5.2 with a 2.2.3 kernel. The box
> but any attempts to download large files (be it HTTP, FTP, samba, etc)
> lead to corruption. It normally crops up in large files (20+ meg)
> but corrupts smaller ones randomly. Zip files pop up with CRC errors,
> Mar 17 19:05:28 server kernel: CPU0: Intel 486 DX/2 stepping 05
> Mar 17 19:05:28 server kernel: eth1: 3Com 3c905B Cyclone 100baseTx at
> 0xd200, 0
You have a 486 PCI chipset with bugs in burst mode.
One work-around is to limit or disable burst mode, but that results in bad
performance. Sometimes an updated BIOS that sets the PCI CacheLineSize
register on the card to a small value avoids the problem. Another
work-around is to avoid using bus-master PCI devices, e.g. use a $10 PCI
The Tulip chips have a burst limit setting that allows working around this
bug, but most other adapter chips do not.
The real solution is to get a non-broken motherboard.
Donald Becker email@example.com
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center, Greenbelt, MD. 20771