[lkml]   [2002]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Flash Back -- kernel 2.1.111
On Sun, Feb 24, 2002 at 04:46:07PM -0500, Jeff Garzik wrote:

> > I have some experimental IDE based code which can detect the PCI bus
> > speed by doing some IDE transfers and measuring the time it takes. It
> > isn't 100% reliable, though. I haven't found any other way to detect PCI
> > clock reliably, unfortunately it cannot be safely guessed from the CPU
> > clock or FSB clock or anything.
> Maybe your code cannot detect the "right answer" perfectly, but at least
> it could be useful as a sanity check, to let you know if the timings/bus
> speed are wildly off...

Yes, but actually the bus speeds are never 'wildly off', the realistic
values being somewhere between 25 to 41.5 MHz, and because all the new
mainboards have the FSB tunable with a resolution of a single megahertz,
almost all values in this range are posible. And even quite small
changes make sometimes a huge difference (works or doesn't).

Vojtech Pavlik
SuSE Labs
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:24    [W:0.061 / U:18.852 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site