Re: sym53c875E-0: PCI clock seems too high

Mr. James W. Laferriere (babydr@baby-dragons.com)
Sat, 25 Sep 1999 15:01:26 -0700 (PDT)


Hello Gerard,

On Sat, 25 Sep 1999, Gerard Roudier wrote:
> The test of the PCI clock is not intended to prevent user from stupidly
> breaking their hardware, but some reality test to prevent the driver from
> being wrong about its estimation of the SCSI clock of the chip. Applying
> the algorithm to the PCI bus and checking the result against the expected
> reality (33Mhz), allows to make sure the algorithm is correct. This
> algorithm is based on the udelay() stuff of Linux that sometimes may give
> weird results, especially on new hardware, and then break the driver
> calculation of the SCSI clock.
I understand your concerns and agree .

> I will NOT remove the reality test of the PCI clock, but allow user to
> tell the driver about the reality they choose for the PCI clock frequency.
> This will be a boot command option that will be defaulted to 33 MHz.
> Probably something like : pciclk=41 to inform the driver about the PCI BUS
> being clocked to 41 MHz.
I thank you very much . Not that I over-clock anything I own ,
a few people I know do . It would be nice if these individuals
would first return their systems to an in-spec clock-rate & then
try duplicate the problem they were experiencing & then if it is
reproducable send out a query to a list .

> I actually donnot care of people who overclock their hardware. I just ask
> them for not wasting our time with problems due to their decision to
> overclock. These people must know that hardware that have been overclocked
> can be definitely damaged and experience far more error than specs said.

> Overcloking a CPU that is in fact sold with an underclocked specification
> is one thing.
I've heard of some re-seller/Oem doing this but not with any of my
oem contacts . I haven't heard any names of re-seller/Oem 's that
do this just a few discussions with disgruntled owners who found
this to have been done to them .

>Overclocking a BUS and then everything that connect to it by
> more than 10% was not imaginable by me. By the way, I think that people
> that overclock PCI 33 Mhz buses up to 41MHz or more are just foolish and
> plain idiot, but I don't care of them.
Total agreement ! Tnx, JimL
+-----------------------------------------------------------------+
| James W. Laferriere | System Techniques | Give me VMS |
| Network Engineer | 25416 22nd So | Give me Linux |
| babydr@baby-dragons.com | DesMoines WA 98198 | only on AXP |
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