Two IDE Controllers?

[Mattazuma]

Can I use two IDE controllers in a PC (One on the MB & one PCI)?

I have four IDE devices and I need more disk space. I'm too cheap to go SCSI.

Thanks,

Mattazuma

 

[Vegito]

What kind of mobo do you have, normally you have 4 ports off 1 mobo unless you have older mobo. But anyway, Standard IRQ is 14 & 15 for almost all mobo as onboard IDE controller so you'll need you get a controller such as promise that lets you jump other irq or share other irq. If the PCI controller uses 14/15 you may run into conflicts.. yeah, it's possible..

 

[Mattazuma]

It's an Abit BX6 Rev. 2.

I am probably going to get a Promise Ultra/100 controller.

 

[BigLance]

I have asked about this and have been told it will work, The "external" (promise etc.) controller will need only boot if your BIOS is set to boot off of SCSI. If you dont want to run your Boot Hard drive(s) off of it, I dont think you really need to do anything, windows takes care of it...

 

[Mattazuma]

Thanks BigLance!

 

[Lord Evermore]

You only have one controller on board the motherboard. That controller has two channels (one physical port each), and each channel can carry two devices, so you can have a total of 4 devices. However because IDE is a master/slave design, you can lose some performance when you put more than one device on each channel.

You can install an expansion card like the Promise controller and thereby add the ability to run another 4 devices (one controller, 2 channels, two devices per channel). So then you'd have the ability to install 8 devices. The expansion card has an advantage though in that it only uses 1 IRQ, whereas each channel of the onboard controller uses an IRQ. So in order to save IRQ's, you would want to use the expansion card first, and disable one or both of the onboard channels in order to stop them from using an IRQ.

So, install as many of your hard drives onto the Promise controller as you can, then use one onboard controller channel to carry two more devices, and disable the other one to save an IRQ. However if you can spread the devices and use one device per channel, you can get a little more performance, but you'll use up a total of 3 IRQ's.

Also, you can't use an expansion card as a boot device if you have a hard drive on the onboard controller's primary channel (possibly also won't work if you have a hard drive on the secondary channel, I never tried that). The BIOS looks for a hard drive on the onboard controller first, and will try to boot from that. If you're using an OS that doesn't have to be installed on the first hard drive (Linux, Win2k) then it can be installed on one of the devices on the expansion card, and the boot record on the hard drive on the motherboard controller can still point to the other drive (however that might take a reinstallation, I don't know).

 

[ElFenix]

i have a hard drive as master on the secondary channel, boots just fine off the promise card. i'd put the second HDD on the promise card but 2 maxtors and a promise card don't mix very well.