3rd party x1900 power issues!

Discussion in 'Mac Pro' started by slughead, Oct 24, 2006.

  1. slughead macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #1
    Hey I just got my PC x1900 and THE COMPUTER wont turn on with the power cord plugged in!

    I'm using a two 4-pin molex -> 6 pin PCIe adapter, and with both plugged in, the power just blinks and turns off.

    With 1 plugged in, the card doesn't work, not even under windows.

    I'm freakin!

    Obviously it's drawing too much power with both plugged in. Does it really require 2?

    More info:
    It's a saphire 512MB open box from newegg.com.

    The power is coming entirely from the optical drive bay which has a hard drive and optical drive plugged in already.
     
  2. MRU macrumors demi-god

    MRU

    Joined:
    Aug 23, 2005
    Location:
    Ireland
    #2
    ^ :eek: eek! nightmare. Is it working with the original card bcak in ?
     
  3. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #3

    yep, everything works fine as long as only 1 power cord is plugged into the aparatus..

    of course, the x1900 doesn't work, just the 7300
     
  4. MRU macrumors demi-god

    MRU

    Joined:
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    #4
    Ok are both the 7300 & ATi in the machine at the same time. Maybe that's what drawing too much power ?
     
  5. Spanky Deluxe macrumors 601

    Spanky Deluxe

    Joined:
    Mar 17, 2005
    Location:
    London, UK
    #5
    Have you got a spare ATX power supply to power the x1900 with to see if it works. Also have you tried it with just the x1900 plugged in and not the 7300GT?

    I wouldn't have thought it be a power issue since people have run 7950 X2 cards before without any issues.
     
  6. mdntcallr macrumors 65816

    mdntcallr

    Joined:
    Aug 1, 2000
    Location:
    Los Angeles, CA
    #6
    hmm, i havent heard that anything but the apple distrib cards work in the mac pro's.

    but i could be wrong.
     
  7. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #7
    Yes

    I have 4 x 7200 RPM hard drives, 1 x 10,000 RPM hard drive, the optical drive, the 7300, and the x1900 in there.

    I'll try a spare ATX.

    I think the problem is simply that the line coming from the power supply has:

    - DVD ROM drive
    - 10,000 RPM hard drive
    - x1900

    I think it's just too much power on that particular power line, and since I have no spares, I'm going to have to buy an internal cable or scrap my 10k HD.

    I'll know for sure when I try out the other PSU.
     
  8. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #8
    The spare ATX PSU works, so it was a power issue after all!

    I got the x1900 flashed and am typing this on a monitor plugged into it right now!

    I'm using a this psu until my GPU -> motherboard cable arrives.

    Hopefully when feeding off a different power line, internal PSU will suffice.

    SO NOW MY DREAM MACHINE HAS BEEN FINISHED!

    - 2.66 Ghz Mac Pro
    - 600 GB RAID-0 (2x300GB Seagates)
    - 250GB Stock HD (Western Digital)
    - 500GB Seagate
    - 80 GB 10,000 RPM Western Digital Raptor
    - 3GB RAM

    All for less than 3 grand!
     
  9. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #9
    By the way, sorry if I was unclear earlier. I'd been inhaling solder fumes all day.

    The Molex -> 6 pin adapter has 2 molex inputs so you can run it from 2 powerlines at once into the card.

    The 6 pin plug on the card has two grounds and one 12 volt plug for each powerline, and a total of 2 powerlines max. However, you only really need 1.

    I cut off both molex connectors and put all the leads in parallel (+12 -> +12, -5 -> -5, -12 -> -12) because I only had 1 powerline in my case, and figured this was going to trick my card into working.

    The 2nd molex connector in my optical drive bay was torn apart when I unplugged it from my 5th hard drive. I used this opportunity to solder in a new molex for the drive area and run a parallel line into the card cavity.

    In the card cavity, I soldered in my 3 (used to be 6) leads from the molex -> 6 pin adapter directly to my newly aquired powerline.

    The problem was, now I had the x1900, 10k RPM HD (which eats up tons of energy) and my DVD drive all in parallel running off a single powerline.

    This powerline was not designed for this, and so the computer would not 'turn over' when I hit the power button.

    I assumed that the card had some auto-detection scheme to see if you had 1 or 2 powerlines coming into it, so I attempted to cut 1 of the powerlines off to try and fool it. I forgot, however, which half of the leads composed each powerline. I cut the most logical 3 and assumed I was right because the computer turned on. However, the card did not.

    The problem was that I'd mixed up 2 of the leads. Once I got that straightened out, I realized that there was no mystical auto-detection scheme and that there was no way my PSU was going to let me pull that much power from that powerline.

    I cut the powerline in the card cavity and attached a regular molex connector to it (cuz I had one and I was soldering and cutting anyway, so I figured what the heck). I reassembled the molex -> 6 pin adapter and attached it to an external ATX PSU. I ran the cable through an empty PCI slot.

    So now, I'm using another PSU exclusively for the card. It works fine.

    I also have a spare molex connector sitting idle in my card cavity. I'm thinking christmas lights.
     
  10. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
  11. MRU macrumors demi-god

    MRU

    Joined:
    Aug 23, 2005
    Location:
    Ireland
    #11
    Thanks for the pictures. You've just convinced me 100% not to go that route ;) :) :eek:


    would doing all that to the connectors not screw up your macpro apple waranty?
     
  12. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #12
    I doubt I'll have a problem, but if I do, I can always remove all that crap and install the old molex.


    Also, the only reason I did all that wiring was because the stupid molex connector in the drive bay ripped off.

    Moreover, as I found out, there's no reason to use the drive-bay cable as it wont supply enough power for the card... unless it was my 10kRPM HD that was the straw that broke the camel's back, in which case you can save $25 by connecting that adapter directly to the optical bay's extra molex.

    Regardless, if you're squeemish about messing with it, you could always pay for the $30 GPU -> Motherboard cable that welovemacs.com sells (find link elsewhere).

    In the end, due to the aforementioned power issue, that's what I'll be doing.
     
  13. Jasonbot macrumors 68020

    Jasonbot

    Joined:
    Aug 15, 2006
    Location:
    The Rainbow Nation RSA
    #13
    Thats so 1337! I just wanna know, does the X1900 only work under windows and the 7300 under both?

    Why can't the mac see the PC Graphics card?

    And: If OS X boots plugged into the PC Card what happens?

    I'm just curious and havent found any answers elsewhere:D
     
  14. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #14

    Well, first off, we've figured out how to change a PC x1900 XT 512MB into a mac x1900 simply by "flashing" the firmware.

    As such, my x1900 now works in windows AND os x.

    Mac OS can't see PC video cards because all Mac video cards need a special piece of software on the card called a "ROM". PC cards come with a "ROM" too but it's different. The ROM, being a piece of software, can be downloaded, deleted, and/or replaced.

    So basically, someone with an x1900 for mac downloaded their ROM and put it on the internet. I then took that ROM and put it into my PC x1900, making it into a Mac x1900.


    The x1900 and the 7300 work in both operating systems now.

    Edit: for more on flashing: http://forums.macrumors.com/showthread.php?t=243610
     
  15. Jasonbot macrumors 68020

    Jasonbot

    Joined:
    Aug 15, 2006
    Location:
    The Rainbow Nation RSA
    #15
    Just a ROM flash, BTW (no offense) I'm not a noob so the explaination on ROM had me ROLFing:D

    Anyways: Cool, is the 1900 the only card you can "convert", `I remeber an old hack (hardware) to turn an old ATi to a mac based card. Lots of soldering...

    But now that the x1900 works on both OSes Y use the 7300?

    //ROM is like the cards OS, not really special software. If it was "special sftware" you'd install it not flash it. I flashed my V3 RAZR
     
  16. eMagine macrumors regular

    eMagine

    Joined:
    Sep 18, 2006
    Location:
    Los Angeles, CA
    #16
    your card is touching the RAM riser housing (which is metal) and it's shorting. make sure the card and the metal housing don't touch.
     
  17. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #17
    Sorry :)

    So far, yes: the 1900 is the only one you can convert.

    When you run 2 monitors on a card, the VRAM is usually cut in half (half for each).

    I run 2 monitors (soon to be 3 again), so I have 1 GPU for each.

    Operating systems are software, whether they be stored on a ROM chip or a hard drive.

    And it's not really an OS, either, it's actually a BIOS (basic input/output system) software. It's still software, it's just the most fundamental software in a computer component.

    My RAM housing has a big piece of plastic on top of it... I donno about yours

    plus, as I said before, this issue has been resolved (mostly)
     
  18. Jasonbot macrumors 68020

    Jasonbot

    Joined:
    Aug 15, 2006
    Location:
    The Rainbow Nation RSA
    #18
    @slughead, ya thats cool! You can't run 3 monitors with extended desktop?

    So I guess when you need to do graphics intensive work you use the X1900 controlled monitor. Wow! The choices!
     
  19. slughead thread starter macrumors 68030

    slughead

    Joined:
    Apr 28, 2004
    #19
    You can, I just don't have 3 monitors yet.. I sold one to help pay for this computer.


    Yeah.. work.. that's it :)
     

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