PCI / AGP Slot

Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
somewhere that the PCI slot to the AGP can only be used if the AGP slot
isn't in use, is that correct?
8 answers Last reply
More about slot
  1. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    Kev wrote:

    > Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
    > somewhere that the PCI slot to the AGP can only be used if the AGP slot
    > isn't in use, is that correct?

    No, that is incorrect. Perhaps what you meant is that they share an
    IRQ. That often is the case.


    -WD
  2. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    Kev wrote:

    > Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
    > somewhere that the PCI slot to the AGP can only be used if the AGP slot
    > isn't in use, is that correct?
    >
    >

    No.

    However, the PCI slot adjacent to the AGP slot shares IRQs with AGP (the
    AGP slot is actually an 'extension' of that PCI slot) and that can create
    problems with certain cards, most notably sound cards (especially if they
    has a 'DOS compatibility' mode which emulates ISA use, which is NOT
    'sharable' like PCI IRQs are).

    The same situation occurs with PCI slots past 4 as they are 'expansion'
    slots from the 4'th and can have problems if incompatible PCI cards are put
    in them; again, most notably, sound cards.

    It comes from the nature of the PCU bus, which is 4 slots. More than that
    and they are, by definition, 'expansions' from the 4 primary slots. And AGP
    is a PCI slot 'plus' the AGP memory access. In fact, until there is any AGP
    memory used, an AGP display card is equivalaent to a PCI display card.
  3. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    Kev wrote:
    > Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
    > somewhere that the PCI slot to the AGP can only be used if the AGP slot
    > isn't in use, is that correct?

    It's not correct, BUT, some video cards that go in the AGP slot are so
    big they interfere with the use of the PCI slot directly next to it,
    which can make it unuseable. But only the latest and greatest video
    cards are that big.

    My mobo for example doesn't even HAVE a PCI slot next to the AGP slot :)
    But for entirely different reasons.
  4. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    "Will Dormann" <wdormann@yahoo.com.invalid> wrote in message
    news:BG0Hc.191557$DG4.98034@fe2.columbus.rr.com...
    > Kev wrote:
    >
    > > Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
    > > somewhere that the PCI slot to the AGP can only be used if the AGP slot
    > > isn't in use, is that correct?
    >
    > No, that is incorrect. Perhaps what you meant is that they share an
    > IRQ. That often is the case.
    >
    >
    > -WD

    Thanks for the reply. I'm not sure what an IRQ is. If I was to install a
    USB2 card into the spare PCI slot would it interfere with the video card in
    the AGP slot? Cheers.
  5. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    "David Besack" <daveREMOVEbesack@mac.com> wrote in message
    news:cci8j0$a61e$1@netnews.upenn.edu...
    > Kev wrote:
    > > Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
    > > somewhere that the PCI slot to the AGP can only be used if the AGP slot
    > > isn't in use, is that correct?
    >
    > It's not correct, BUT, some video cards that go in the AGP slot are so
    > big they interfere with the use of the PCI slot directly next to it,
    > which can make it unuseable. But only the latest and greatest video
    > cards are that big.

    With my video card, there'd be room to fit a PCI card into the slot next to
    it, but it'd be pressed right up against the video card and would cover the
    fan on it. I'm not sure if it'd be safe to do that. Can anyone advise?

    > My mobo for example doesn't even HAVE a PCI slot next to the AGP slot :)
    > But for entirely different reasons.
  6. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    "David Maynard" <dNOTmayn@ev1.net> wrote in message
    news:10ep89m3v338cfa@corp.supernews.com...
    > Kev wrote:
    >
    > > Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
    > > somewhere that the PCI slot to the AGP can only be used if the AGP slot
    > > isn't in use, is that correct?
    > >
    > >
    >
    > No.
    >
    > However, the PCI slot adjacent to the AGP slot shares IRQs with AGP (the
    > AGP slot is actually an 'extension' of that PCI slot) and that can create
    > problems with certain cards, most notably sound cards (especially if they
    > has a 'DOS compatibility' mode which emulates ISA use, which is NOT
    > 'sharable' like PCI IRQs are).
    >
    > The same situation occurs with PCI slots past 4 as they are 'expansion'
    > slots from the 4'th and can have problems if incompatible PCI cards are
    put
    > in them; again, most notably, sound cards.
    >
    > It comes from the nature of the PCU bus, which is 4 slots. More than that
    > and they are, by definition, 'expansions' from the 4 primary slots. And
    AGP
    > is a PCI slot 'plus' the AGP memory access. In fact, until there is any
    AGP
    > memory used, an AGP display card is equivalaent to a PCI display card.
    >

    Hi, do you think there would be any problems having a usb2 card installed
    next to a 128MB Radeon 9800Pro video card? Cheers.
  7. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    Kev said this...

    > With my video card, there'd be room to fit a PCI card into the slot next
    > to it, but it'd be pressed right up against the video card and would
    > cover the fan on it. I'm not sure if it'd be safe to do that. Can
    > anyone advise?

    I believe your instinct here is right. It's not a gamble that I would care
    to take. Modern GPU chips produce a LOT of heat.
    --
    º~ david ~º
  8. Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

    Kev wrote:

    > "David Maynard" <dNOTmayn@ev1.net> wrote in message
    > news:10ep89m3v338cfa@corp.supernews.com...
    >
    >>Kev wrote:
    >>
    >>
    >>>Hi, my motherboard has an empty PCI slot next to the AGP slot. I heard
    >>>somewhere that the PCI slot to the AGP can only be used if the AGP slot
    >>>isn't in use, is that correct?
    >>>
    >>>
    >>
    >>No.
    >>
    >>However, the PCI slot adjacent to the AGP slot shares IRQs with AGP (the
    >>AGP slot is actually an 'extension' of that PCI slot) and that can create
    >>problems with certain cards, most notably sound cards (especially if they
    >>has a 'DOS compatibility' mode which emulates ISA use, which is NOT
    >>'sharable' like PCI IRQs are).
    >>
    >>The same situation occurs with PCI slots past 4 as they are 'expansion'
    >>slots from the 4'th and can have problems if incompatible PCI cards are
    >
    > put
    >
    >>in them; again, most notably, sound cards.
    >>
    >>It comes from the nature of the PCU bus, which is 4 slots. More than that
    >>and they are, by definition, 'expansions' from the 4 primary slots. And
    >
    > AGP
    >
    >>is a PCI slot 'plus' the AGP memory access. In fact, until there is any
    >
    > AGP
    >
    >>memory used, an AGP display card is equivalaent to a PCI display card.
    >>
    >
    >
    > Hi, do you think there would be any problems having a usb2 card installed
    > next to a 128MB Radeon 9800Pro video card? Cheers.
    >

    Probably not but, as a general rule, I try to avoid having network cards,
    and other high data rate devices, sharing with the display.
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