PCI-X in Gigabit Ethernet PCI Slot

Discussion in 'PowerPC Macs' started by pkmgarf, Sep 18, 2011.

  1. macrumors newbie

    I'm working on setting up my G4 as my houses server. It will be performing a variety of functions (file, print and internet sharing, along with whatever else I need). It's also Linux based (don't worry, it's up and running already - that's not why I'm here).

    Where I'm at, is setting it up as my router. I purchased a 4-port gigabit ethernet PCI-X card to use, but am a little disappointed. Everything I read online states that PCI-X is backwards compatible with PCI (only that it will run at a lower speed). Unfortunately, the PCI slot on my logic board is not quire right - there's an area with a plastic "block" in it (regular PCI cards don't have a pin in this spot), but the PCI-X card I have does not have a notch for it.

    There's no pin on the card in this spot, just some extra circuit board. My question is this - has anyone successfully installed a card like this in a Powermac logic board?

    I can post pictures if necessary. I'm planning on Dremel-ing the PCI-X card to fit, but I figured I'd check on some forums first...
  2. macrumors 65816


    Can you post pics?
  3. macrumors 68000

    Would cutting the inside out help?


    They used to cut the keys out of the connectors on Dell's low end servers, so you could put a high-power GFX card in (they were cheaper then the low-end desktops and better-built).
  4. macrumors newbie

    Well, I jumped the gun and grabbed the Dremel. The pics are below. Unfortunately, the Dremel's cut off wheel is a little small, so I had to go in at an angle. As you can see, I got a little close to the pins, but there is still material there. I don't think I messed anything up, but the machine will not boot with the card installed. I tried it in each port, and with it as the only card installed. All that happens is the power light flashes, and fans on the processor start to spin (briefly), and then it stops.

    Everything works fine with the card out. I'm going to try and find a PC to throw the card in and see if it boots...not sure what else to try...

  5. macrumors 6502a

    PCI-X SLOTS are backwards compatible with PCI cards, not the other way around. You can run a normal PCI card in a PCI-X slot, but the PCI-X card can ONLY be run in a PCI-X slot.

    In your case, it appears you have a PCI-X slot, but it's of the wrong type for your card. My guess is that your card isn't made for Macs, given that it says Intel on it :p

    Even if it did work, there may not be compatibility for it in OSX.
  6. macrumors 68020


    This is all 100% correct. Very well explained also.

    I see the OP has the identical XFX GeForce 6200 low profile AGP card I do in my Sawtooth. Anything to help the airflow inside these little towers.
  7. macrumors member

    The rule-of-thumb with PCI cards and slots is: if the card fits, it'll work (electrically; there's always the issue of drivers). If it doesn't fit, it's not going to work because it wasn't designed for that type of slot (even if drivers are available).

  8. pkmgarf, Sep 19, 2011
    Last edited: Sep 19, 2011

    macrumors newbie

    I think you guys might be mistaken. I did a lot of reading, and PCI-X should work in a PCI slot. The PCI slot in my Mac is of the universal 3.3v or 5v, 32 or 64 bit variety. This slot *should,* from what I understand, work with just about any card you can put in it.

    The card I have is keyed for a 3.3v, 64 bit PCI-X slot. This slot type uses a different key layout than the universal slot that is on my motherboard. However, the only pins that are different are pins 50 and 51, which according to all the pinouts I've looked at, are open/ground.

    All of the slot types can be found on Wikipedia, along with a comparison. A good pinout is here.

    Everything I've read says that the PCI-X card will simply run at the 33 mhz speed of a standard PCI slot, limiting it's data throughput. For those that are doubtful, check out this link. PCI and PCI-X are pretty much the same damn thing.

    Also, I fully understand that my Intel card is not a standard "Mac" card. However, I am not planning to use it under OS X, and the research I've done on the Linux driver seems like it works well. Also, I did do some other reading, and it looks like the Intel Pro1000/MT is compatible with OS X using a native Apple .kext.

    **edit, added some links
  9. Guest

    PCI-X cards are backwards compatible with full lenght PCI slots. I own 2 PCI-X cards and I don't have PCI-X slots since I'm on a G4 MDD. No problem.

    I do not want to mess things up, but the reason why that card doesn't fit must be something else than "PCI-X SLOTS are backwards compatible with PCI cards, not the other way around".

    Truth is it works both ways, but when you put a PCI-X card in a PCI slot, it will run a slower standard PCI speed.

    Edit: PCI-X and 64 bit/ 33mhz PCI are almost the same thing. 32 bit PCI slots on the other hand, are not. Thanks Apple for using 64 bit PCI in all G4s (unlike on most PCs).
  10. macrumors 6502a

    I'm now getting confused.

    OP, can you post a picture of the card installed in your PCI-X slot?

    Is "Full Length" PCI different from a normal 32-bit PCI slot commonly found in consumer-level PCs?
  11. macrumors newbie

    I'll get a picture up in the morning. The system is running my wifi network right now.

    And the PCI slots in the G4 are 32/64 bit slots ("full length," as a standard, 32 bit slot is shorter).
  12. pkmgarf, Sep 20, 2011
    Last edited: Sep 20, 2011

    macrumors newbie

    Well, I did some more research, and posted a thread over on Tom's Hardware forums (as this is more of a hardware issue than a Mac-specific problem).

    I found this page on Intel's website, stating that the quad port adapter is only compatible with 3.3v ONLY slots, and not the 3.3/5v universal. I wish I would have found that page before I bought the card - the only requirements listed ANYWHERE else is PCI 2.2/PCI-X.

    My thread on Tom's Hardware basically tells me that unless I can find a way to force the PCI slot into 3.3v mode, this card will not work, even though it now physically fits in the slot.

    Something about the card not having the logic to decide between 3.3v or 5v on a universal slot - - this I am unsure of though, as the dual port card (which is, as far as I know, VERY similar to my quad port) has this logic, and is keyed for the 3.3v/5v universal slots.

    I did email Intel, as well. They were no help: "Voided warranty by rekeying...does not work in your slot..." No explanations, just simply that it won't work.
  13. macrumors 6502

    Dave H

    Maybe you could tape the 5v pins on the card, like how the 3 and 11 pins have to be taped with flashed 8x AGP cards in G4s.
  14. macrumors newbie

    There are no 5v pins to be taped...the card has no "extra" pins.

    I'm thinking this "logic" to pick 3.3v or 5v is in the ROM on the card? Maybe? Or is it hardware? I'm not sure.
  15. macrumors 6502a

    Even if this card worked, or even if you GOT this card to work, how do you know OSX can even recognize all four ports?? Are there any four port adapters available for these computers that ARE supported, and this Intel card shares the chipset perhaps? Without knowing for sure, you might be wasting time.
  16. macrumors newbie

    As I mentioned, I'm using Linux, so no worries with Apple drivers. Also, there is a native Apple .kext in OS X that should recognize this card, if it would boot.

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