R40 disk not in DMA mode

[Mike-NOAA]

I'm still trying to get my R40 (2681-L7U) to be a more usable system for my work. Today I am asking for help from others using an R40 with the 60 Gb disk.

Mine will not run in DMA mode; instead, it's running in PIO mode, which is very slow. Indeed, it is the limiting factor in the speed of the machine.

I would appreciate info on whether others using this machine type are also having this problem.

From Windows, this can be checked with Start -> Programs -> Administrative Tools -> Computer Management -> Device Manager. Open up the tree under IDE ATA/ATAPI controllers, and double-click on "Primary IDE Channel." Under "Advanced Settings" for Device 0, the transfer mode should be "DMA if available." Just under that is the current transfer mode, which on my machine reads "PIO Mode." Does anyone have an R40 on which this indicates some form of DMA mode?

Thanks!

[Bunzer]

a bit late for a reply, I suppose.

I just went through this yesterday, with my R52. I bought it recently for use as a "musical instrument" - with music software and controller peripherals. I added a CardBus sound interface, with which I've had trouble setting-up.

Anyway, I think what has happened is that the interface has hogged the buss and caused the o/s to think that the hard disk has timed-out. Apparently, when the o/s thinks the hard disk is dodgy, it drops the i/o specification, and doesn't put it back again. Therefore, you are unable to enable DMA Mode in the driver settings.

After a quick Google, I found something useful here. I found that deleting the MasterIdDataChecksum value and setting the MasterDeviceTimingModeAllowed value to 0xffffffff has fixed the problem and (so far) stopped it from happening again. The hard part is finding the correct key.

[Mike-NOAA]

Keith,

Thanks for the information. IBM eventually replaced the disk in my R40, which solved the problem. Still, even when working properly, the factory-supplied disk runs at 4200 RPM, which makes it a bottleneck. I've since replaced the R40 with a laptop with a disk running at 7200 RPM. Total system response is much faster.

More and more, I am finding that hard disks are THE bottleneck in my kind of computing, and that for workstations, SCSI provides a greater performance boost than increasing processor speed. Unfortunately, SCSI isn't an option for laptops.