IDE HD slows down my comp

[FerDan]

I have 3 Hard disks in my comp....: a 30gb IDE seagate ST330621 , a 10gb IDE Samsung SVA844 , and a 9gb Quantum Atlas SCSI (on a Adaptec UW2940).. the problem is that when the 30gb ide and the scsi are running at the same time.... the computer gets slow... and have really annoying pauses.... just like when the floppy drive is in use. And i´m using the SCSI as principal... so ihave the swap file there... so everytime I use the 30gb ide.... everyhing gets slow. Nothing bad happens when the 10gb ide works. Someone told me it could be an IRQ problem.... but I don't think so, anyway the thing is i think my motherboard bios don't have the options to manually select the IRQs
it's a Soyo K7VTAPRO-2AA7.

Do you have any idea if there's a fix for this problem?

both ide hd are as master in 2 different ide channels

[mike breck]

Well even taking into account the difference in transfer rates between the SCSI and IDE, you would not expect the whole system to slow down like that. From what I've read, SCSI and IDE HDs can work well together on setups like yours.

Is UDMA enabled on the 30Gb? Have you tried setting it to Cable Select and using an ATA66/100 80 wire/40 pin cable? Blue to mobo and black to the HD.

[FerDan]

I should try that.......... btw.... I found that when I enable DMA trasnfers on the big ide hd...... it gets even more slow!

[GaryRouth]

Looks like you have the latest Bios for your board (2aa7), so I'm surprised you see slowing. I was thinking of the 686b IDE problem that surfaces in some systems with the KT133, KT133A, and KT133E VIA chipsets. So, that's probably not it, but you can look at some documentation about it, just in case:
http://www.viahardware.com/686bfaq.shtm

Also surprised to see the ISA slot at the bottom of that board. Is your SCSI adapter in the PCI slot next to it? If it is, try moving it up to a different slot.

And with Ultra-DMA, some drives need to be set with a separate little program that comes with the drive when you buy it, to have it run at it's highest rated burst transfer speed (UDMA 100 for the Seagate). The Seagate tool is probably in the SeaTools group.

. . . Gary

[p.s....your big drive probably would slow if you enable DMA and have the older Ultra DMA-33 40wire cable instead of the newer Ultra DMA-66/100/133 cable (80wire), because the system would detect transfer errors and eventually disable your DMA]