Laptop PIO4 or UDMA-2 question (Vendor or me that is wrong?)

randypj

Platinum Member
Oct 9, 1999
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I've got an XL-2 Winbook that I received ~12/15/99. Winbook and I are having a difference of opinion as to the legitimacy of the hard drive that is included with it. The drive is supposed to be a 6.4 gig UDMA-2 (33). The BIOS shows it to be PIO-4. The chipset is evidently a laptop version of Intel BX.

Winbook feels that the hard drive is an UDMA-2, but the BIOS will only show it as PIO-4. My feeling is that, even if it is an UDMA-2, it is not fully supported by the BIOS or chipset, hence, not as represented.

Rather than sending the laptop in, I told them that I would first bench it with whatever their techs used, which is Winstone or Winbench. They did say that they stopped shipping non-UDMA hard drives about a year ago. Possibly, they made a mistake, and shipped the wrong hard drive with it. Possibly I am incorrect in my thinking.

Comments welcome.
--Randy
 

Floyd

Senior member
Nov 17, 1999
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The only thing that comes to mind is what you've already mentioned...the BIOS. Do they have a BIOS update for the motherboard, or are they pricks about it and insist upon you sending it to them? To the best of my knowledge, DMA must first be supported by the BIOS, only then can it be optionally enabled in the operating system. So I think it is pretty much a dead end if the BIOS will not recognize it as supporting DMA.

Best regards,
Floyd
 

NicColt

Diamond Member
Jul 23, 2000
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I'll take a wild shoot at this....
I have an older ATA/66 HD that when it's on a normal IDE cable on the mobo controller it shows up in the mobo's bios as PIO-4 but when I put it on a ATA/100 cable the Promise BIOS sees it as UDMA2. It may be that both are correct. Just that one shows up as PIO-4 on a non ATA/66 controller and UDMA-2 on an ATA/66 controller. I could be wrong though but that's my 2 cents.

I forgot to say that I think UDMA-2 is taking advantage of the ATA/66 and PIO-4 is only running at ATA/33. So it's the same drive but depending on which ATA/cable or controller you put it on it will show up differently.

When someone says that there drive is UDMA-2 or UDMA-5, that's taking into consideration that you are using it with the appropriate controller's and cables, but then again all drives are backwards capable depending on what hardware your using it with.