From: Taiwan, R.O.C
I got some strange situation that all my IDE drives can use UltraDMA in the begining, but for unknown reason, one of it can only use PIO mode.
My motherboard's chipset is VIA KM133A and with AMD Athlon 1500+ CPU.
OS is Windows XP Pro.
IDE bus 1 connect with: Maxtor 120GB HDD and BenQ DW1600
IDE bus 2 connect with: Asus E161P DVD-ROM and LiteOn 163S CD-ROM
The UltraDMA become unavailable to one of the drive more than 2 times. One is the Asus DVD-ROM can only using PIO mode. I resolve it by switching it with LiteOn 163S to let Windows XP though there are some new hardware. Then all drives can use UltraDMA.
But not so lucky. Recently, the BenQ DW1600 got the same problem that UltraDMA becomes unavailable. I even install VIA's 4in1 driver which is including IDE Bus Master driver. But not working.
Well..... I can't figure out what's the problem. So, I switch the drive's connected channel again. Now they become:
IDE bus 1 connect with: Maxtor 120GB HDD and Asus E161P DVD-ROM
IDE bus 2 connect with: BenQ DW1600 and LiteOn 163S CD-ROM
Although this resolved my problem, but I don't think this is a good idea. What if it happens again?
Does anyone know the exactly problem is and know how to prevent from it / resolve it?