I had THE SAME PROBLEM OF YOURS with an alphastation 255 (233MHz),
the sams symptoms. I could make it crash everytime with a machine check
if I use dd with a huge blck size copying a huge file into another.
Try this. Create a 500MB file and try dd with a very big bs like
bs=50000000 and see if it will crash.
On my alphastation it was crashing all the time I run this test.
In my case it was a bcache problem and there was nothing to do, I had to
throw my Alphastation away... I hope this is not your problem anyway...
the symptoms looks like the same. The cache modules being very hot it's
quite normal. I had also put a supplementary fan cooler but it did not
work...

Rick


On Sat, 8 Mar 2003, Manuel Bouyer wrote:

> Hi,
> I have an alphastation 255 (233Mhz) on which I get machine check during
> heavy usage: pci bridge fault while heavy usage (copy from a NFS server
> to a local IDE disk) or processor fault during heavy CPU usage (package
> compile). I tried 2 different RAM sets, and tested the 2 RAM bank on
> motherboard individually. So this doesn't seem to be a problem with RAM
> or with the RAM socket on motherboard (or several of them are brocken).
> Opening the case just after such a crash, I noticed that the CPU and chips
> around it are quite hot (I can barely keep a finger on them). The front fan
> looks OK, but maybe the air flow is lower than it was. Any comment on this ?
>
> Also, I changed a bit of hardware: added a 3com 100Mbs NIC (also tried
> a 21140-based NIC, didn't help), a pciide adapter (tried different Ultra33 and
> Ultra66 models) with and IDE disk (I keept the origial SCSI disk for system)
> and remplaced the floppy drive with a SCSI ZIP. I keept the origial SCSI
> cdrom drive. The 255 manual says it can support up to 3 internal SCSI disk in
> addition to the CD, so I guess the power supply is enouth for all this
> (I don't think the ZIP eats significantly more than a floppy drive when idle,
> and I can't see the extra nic + extra IDE controller eating more than
> a hard disk). Again, any comments on this ?
>
> --
> Manuel Bouyer <bouyer@antioche.eu.org>
>      NetBSD: 24 ans d'experience feront toujours la difference
> --
>