On 14.02.00, 00:51:24, Jonathan R. Hinds wrote:
> On Mon, 14 Feb 2000, Frederick Bruckman wrote:
> 
> > My 486dx4 compiles a custom kernel in about 30 minutes, generic in
> > about 45. I don't think you fried the chip, either. I have fried
> > chips--they smoke, and leave burn scars in the socket, and then the
> > machine doesn't boot.
> > 
> > Does the hard drive probe as supporting DMA ("grep ^wd
> > /var/run/dmesg.boog")? If not, if you're stuck at PIO mode 0, say,
> > swapping is going to be incredibly slow. You might see a huge
> > performance boost with a different hard drive, or even by fiddling
> > with the flags for wdc* and wd* in the kernel config file, per the
> > comments in .../i386/conf/GENERIC.
> 
> dmesg says the follow about the controller and hard drive:
> 
> wdc0 at isa0 port 0x1f0-0x1f7 irq 14
> wd0 at wdc0 channel 0 drive 0: <QUANTUM FIREBALL1280A>
> wd0: drive supports 8-sector pio transfers, lba addressing
> wd0: 1222MB, 2484 cyl, 16 head, 63 sec, 512 bytes/sect x 2503872 sectors
> wd0: drive supports PIO mode 4, DMA mode 2
> 
> Does this mean that it is using DMA? I guess that I will try another hard
> drive and see what happens.

No, this just tells you what the drive claims to support. The kernel
will tell you a few lines later what it's actually using for that
drive, like so:

[...]
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 4
[...]
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
                                                      ^^^^^^^^^^^^^^^^^^^^^^^^
So I guess only if you get this, the machine is actually using DMA to
transfer data, otherwise it's polling.

> 
> --jon

-- 
Bernd Sieker

Unix, the solution to the W2k problem.