What is going on? UDMA66 and UDMA33 compatibility problem

[weeber]

OK, here's my story. I have an T-bird 900 on a Soyo K7VTA motherboard with the onboard UDMA66 controller. I also have a 20gig Western Digital UDMA66 drive as master and a 6.4gig WD UDMA33 drive as slave on my primary controller. My secondary controller has a DVD and a CDRW.

Here's the trouble, when I have UDMA66 enabled on my master drive, I can't get my slave drive to run properly with UDMA enabled. MP3s will skip, scandisk will freeze on the first sector for a thorough scan, and sometimes the FAT table becomes corrupt.

However, when I disable UDMA66 on my master drive so that it is limited to UDMA33 (through software provided by WD), I can get both drives running perfectly with UDMA.

So my question is, does anyone know what the problem is? It seems that I can either have fast UDMA with one drive only, or somewhat slower UDMA for both drives, but I can't have both. I don't think it's a problem with the IDE cable, because the master drive would run fine with UDMA66 (according to HDTach, it was performing at 66 speeds).

So, I'd really appreciate it if someone could solve this riddle for me.

 

[bacillus]

are you using an ATA 66/100 ide cable?

 

[weeber]

Like I said, I believe I'm using an ATA66 cable. I'm using the one that came with the motherboard...and I've never had a problem with the 66 drive, just the drive that tries to run at 33.

 

[NoreagaCNN]

Hmmm, sounds like your ATA 33 HD is slowing down your ATA 66 HD down, if you try to connect 2 different speed HD's on 1 connector they'll both go down to the slowest setting to work together. You should either get an IDE controller card or get a faster HD.

Laterz,
Nore

 

[DaddyG]

NoreCNN, what you claim is no longer true. IDE Controllers in modern chipsets support a feature called 'Independant Device Timing'. Each device runs at its own speed. Do you have the master connected to the black connector on the cable, with the slave on the grey ??

Have you tried setting both drives to Cable Select instead of Master/Slave ??. This setting sometimes resolves odd-ball timing issues. You could also try a new ATA66 cable.

 

[weeber]

Thanks DaddyG, I'll try the cable select option sometime. I've never messed with it before.

Right now I have the master drive on the end of the cable, while the slave is in the middle. I've heard this is the best way to set it up.

 

[Wuming]

DaddyG: when you say modern chipsets is BX included? or is it just the very new motherboards that have this feature?

 

[DaddyG]

I am not exactly sure when the feature was implemented in which chipsets. AFAIK BX chipsets don't support ATA66 natively could be wrong cause its been awile since I built a system with BX. For more info, check out storagereview.com as I'm pretty sure that they have an article which discusses Independant Device Timing.