Re: Wow! Is memory ever cheap!

Gérard Roudier
2001-05-09T19:23:29Z

On Tue, 8 May 2001, Dan Hollis wrote:

> On Tue, 8 May 2001, Larry McVoy wrote:
> > which is a text version of the paper I mentioned before. The basic
> > message of the paper is that it really doesn't help much to have things
> > like ECC unless you can be sure that 100% of the rest of your system
> > has similar checks.
>
> UDMA has crc, scsi has parity, pci has (i think) parity, tcpip has crc,
> your cpu l1 and l2 have ecc...

SCSI Ultra-160 has CRC.

PCI has parity (btw, you think right), but only a few drivers make sure
PCI parity checking is enabled. On the other hand, a PCI parity error
should be considered as extremally serious and the system should be
stopped when such happens.

Btw, it seems (read at the pci list) that the original PCI hadn't parity.
After all, PCI had been designed for PC machines... :)

> Looks like similar checks are already there.
>
> -Dan
>
Gérard.