DMA modes changing/turning off

[BlindSeaman]

I have a new WD I 80 gig drive, the one with 8mb's of cache. Its a great drive but, I can't get it to stay in Ultra DMA 4 mode. It boots up in this mode but, then changed to DMA 0 after I do some stuff then to PIO mode. In PIO the performance is horrible and it sometimes can't even play MP3's smoothly let alone videos any ideas on why its changing my modes? Thanks.

It ended up being the cable

 

[WarCon]

First off you should be wanting it to run in UDMA Mode 5 as that is ATA100. If your running XP as your OS then you may be experiencing alot of CRC errors. XP automatically downgrades performance of your hard drive if it starts getting these errors. It could be caused by a bad cable, bad drive or even bad mobo. Even a bad powersupply could cause problems like this.

If your not running XP then I have no clue......

 

[BlindSeaman]

Yes I am running XP and thanks for the help but, damn thats a lot of possibilities. Is there anything I should try first?

 

[WarCon]

Change your cable first. Even try an older 40 conductor cable if thats all you have laying around. If it still degrades to PIO performance then you can rule out the cable.

Have a spare drive laying around? Like the one you just upgrade from. Does it do the same thing?

You could also try the Data Lifeguard v2.8 diagnostic software to see if its your drive. (You will have to create the disk from this program on Win9x/ME though)

 

[BlindSeaman]

I definetly appreciate the help WarCon. It ended up being the cable I have an ata 33 in now and its in DMA mode 2 and staying. I'll get a new ATA 100 cable later. Thanks again.

 

[BlindSeaman]

ack, ok its not the cable. ugh it seems to downgrade modes the more i use my comp. i can't run the hd diagnostic yet since i don't have a win98 machine.