Re: Two PCI device with the same Dev. ID & Vendor. ID

[Andrew Ircha <api@art-render.com>]

Young-Su Kwon wrote:
> Information that I have found :
> 1. In PCI 2.2 spec., there is "subsystem ID" but that is not for
> the cards from the same manufacturer.
> 2. Although "subsystem ID" is supported in PCI 2.2 spec., the
> Windows device driver does not have "subsystem ID".
> 3. This problem is the same for the case when two grahics cards
> that are the same model from one manufacturer are installed.
> 4. I remember that two PCI voodoo cards
> (Old model of graphics card from Voodoo) can be installed
> to boost up the system performance. How can it be possible?

The subsystem vendor ID should have your company's number, which is
assigned by PCI-SIG. The subsystem device ID is your choice. So I think
point 1 is incorrect.

The Windows driver usually reads the vendor id, device id, subsystem
vendor id, subystem device id and revision to install the correct
drivers - so I think point 2 is incorrect most of the time. Do you mean
that you can't see the "subsystem ID" in the device manager?

I don't know how you can plug two graphics cards into one workstation
and expect them both to work. If that were the case, why would people go
to the trouble of making twinhead graphics cards?

All the best,



Andrew Ircha