UDMA Mode 5 Not Available!

[Tom Popp]

I have a FIC AM39L motherboard with VIA KM400 chipset that supports UDMA
Mode 5 (ATA 100) and my hard drive (WD800EB) supports it as well, but I
can't get above UDMA Mode 4 as shown in Windows Device Manager.

I am using Windows XP SP1 and I've tried it with and without VIA's "4in1"
drivers.

WD's diagnostics show that the drive is in Mode 5 when I boot to DOS, but
Windows shows otherwise.

Any ideas?

Thanks!

Tom

 

[NoNoBadDog!]

You have to use the right cable. The UDMA cable has 3 different colored
connectors;
the blue connector goes to the motherboard
the black connector goes to the master HDD
the gray connector goes to the slave HDD

It is recommended to set the drive jumpers to cable select.

If it still does not work, then the mobo controller has throttled back to
DMA4 because it has determined that your setup cannot handle the bandwidth
of UDMA5.

Bobby

 

[Mike Powers]

Are you using an 80 conductor cable? Although I don't think it is
absolutely necessary WD on the last drive I bought says even if you use
master /slave jumper settings to put the drives on the right place on
the cable as mentioned below.

 

[Tom Popp]

I'm not sure about the cable, but since the HD came with
the PC, I would "hope" they used the correct cable.

I can check the cable anyway.

Thanks!

Tom

 

[Bob Willard]

I'm not sure about the cable, but since the HD came with
the PC, I would "hope" they used the correct cable.

I can check the cable anyway.

Thanks!

Tom

There is no diff. between a U/133 cable and a U/100 cable; the only
two IDE cables are for U/33 and slower (40-wire) and faster than
U/33 (80-wire).

IIRC, XP doesn't support U/133 with standard drivers. But, it is
no great loss, since no shipping HD is bottlenecked by U/100; the
spec. that matters is STR: few HDs push U/66, nothing pushes U/100.

The only time U/133 matters is if you have two devices on the same
IDE cable, *and* you have drivers and apps that actually issue lots of
concurrent R/W commands to both devices. With WinDuhs on client PCs,
that is kinda rare.

 

[Roj]

The only time U/133 matters is if you have two devices on the same
IDE cable, *and* you have drivers and apps that actually issue lots of
concurrent R/W commands to both devices.

Even so that will not matter - conventional IDE is an "either / or"
affair as far as device access on the same channel is concerned. Now
if you were talking about IDE RAID...

 

[Bob Willard]

Even so that will not matter - conventional IDE is an "either / or"
affair as far as device access on the same channel is concerned. Now
if you were talking about IDE RAID...
--
Roj

"To strive, to seek, to find, and not to yield."
- Ulysses

Right for data transfer, but some IDE HDs do support queued commands,
which allows seeks on one HD to be overlapped with data transfer on
the other HD. I'm not arguing that it makes much difference, since
it only helps with rare WinDuhs apps and rare HDs under rare
circumstances at some rare phase of the moon when honest politicians
are in office to produce this very-rare benefit.

 

[Frank]

The WD data lifeguard tools diskette (get the latest version),
has a feature to enable/disable the proper UDMA mode.
It won't hurt to check this out.


| You have to use the right cable. The UDMA cable has 3 different
colored
| connectors;
| the blue connector goes to the motherboard
| the black connector goes to the master HDD
| the gray connector goes to the slave HDD
|
| It is recommended to set the drive jumpers to cable select.
|
| If it still does not work, then the mobo controller has throttled back
to
| DMA4 because it has determined that your setup cannot handle the
bandwidth
| of UDMA5.
|
| Bobby
|
|
| > I have a FIC AM39L motherboard with VIA KM400 chipset that supports
UDMA
| > Mode 5 (ATA 100) and my hard drive (WD800EB) supports it as well,
but I
| > can't get above UDMA Mode 4 as shown in Windows Device Manager.
| >
| > I am using Windows XP SP1 and I've tried it with and without VIA's
"4in1"
| > drivers.
| >
| > WD's diagnostics show that the drive is in Mode 5 when I boot to
DOS, but
| > Windows shows otherwise.
| >
| > Any ideas?
| >
| > Thanks!
| >
| > Tom