Guide to A7N8X in Linux

[danielk]

Since the other linux forum seems dead, I'm posting a link to my thread there about this topic. Please visit http://www.nvnews.net/vbulletin/showthread.php?s=&threadid=6946 for the link to my guide.

--Dan

[bwkaz]

There is one thing I want to say about that.

The bold part of this line:

kernel /vmlinuz-2.4.21-pre3-ac4 ro root=LABEL=/ hdd=ide-scsi idebus=66 ide0=ata66 ide1=ata66 is NOT going to improve your IDE bus speed, at ALL. In fact, if your kernel doesn't enable DMA, it will very likely either crash the system, or corrupt your hard drive.

That parameter (idebus) controls what the kernel thinks your PCI bus speed is. The kernel needs to know this if your hard drive is in PIO mode, so that it knows how to time requests to the drive. Since very few PCI buses are actually 66MHz, this is almost always wrong. And if the kernel goes into PIO mode, and sends data twice as fast as the device can receive it, it'll either lock up, or lose data, neither of which are good.

My advice would be to get rid of that idebus=xx in the menu.lst file.

Other than that, though, it looks as good as I can figure (since I don't have an a7n8x board)

[danielk]

I have changed my guide to add this warning, and have removed it from the parameters in the menu.lst file. I no longer use it on my personal machine, either, but I was using it for days with no problem.

Is there no chance that it's actually correct?

Anyways, thanks for the advice, you're now mentioned in the Thanks section.

--Dan

[bwkaz]

You were probably using it for days with no problem because you had DMA enabled on your drives.

It only affects anything when the drive is in PIO mode (i.e. no DMA).

The whole problem with setting it to 66, though, is if your DMA controller ever reports an error, the kernel will reinitialize the IDE bus in PIO mode. Which means it'll start using the idebus=xx parameter. Which means you'll (very likely, according to what little I understand of the IDE system) start losing data. Obviously this hasn't happened to you, but I'd hate for it to happen to someone else. :)