8800GTS 512 for old Mac Pro

Discussion in 'Mac Pro' started by Chocomonsters, Apr 24, 2008.

  1. Chocomonsters macrumors regular

    May 22, 2007
    Has anyone tried to flash 8800GT 512 efi32 rom on 8800GTS 512 for early Mac Pro?

    First, thanks to Altimeter88 for posting 8800GT 512 efi32 rom.

    I will try it on 8800GTS 512 tomorrow. I have EVGA 8800GTS KO 512 (part#512-P3-N845-AR). It has right EEPROM size. I am planning to reclock Bios back to factory overclocked speed of 670 MHz GPU, 1674 MHz Shader, and 1940 MHz (effective memory) using NiBiTor. I've ran this card at 800 MHz GPU, 1920 MHz Shader, and 2000 MHz (effective memory) in PC, but I am a bit afraid to run it that high in Mac Pro.

    I am not sure how flashing 8800GT rom will work under OS X. I assume it will run at reference 8800GT setting of 600 MHz GPU, 1500 MHz Shader, and 1800 MHz effective memory.

    Anyone have any idea if 8800GTS will run 128 Stream Processors versus 112 Stream Processors of 8800GT?

    What if the card was reflashed with 55k 8800GTS PC bios rom, will EFI portion remain (which I doubt)?
  2. Max-8888 macrumors newbie

    Apr 15, 2008
    If you flash the Apple Firmware, it will run with the Apple defalut speeds....

    No why should a part of the old firmware remain? You get a card which acts like the Apple one.
  3. Elandrion macrumors newbie

    Jan 13, 2008
    I just flashed my eVGA 8800GTS (more info about my card here) with the 32bit EFI rom which Altimeter88 posted earlier.

    pro: the card works in OSX as expected, similar to the cards people flashed with the 64bit rom in the GTS thread

    con: Windows doesn't boot up, I just get a black screen after the EFI boot drive selector screen. Again, this is similar to the problems people described in the GTS thread. Also, as NiBiTor can't edit the 32bit rom yet, it is not possible to easily create a rom with the correct GTS clock rates; I do hope one of the rom editing gods may be able to change that though.

    Appended are 2 screenshots from the system profiler, and one from a benchmark in OpenGL Extensions Viewer.


    edit: so yea, after I ripped out the old ATI x1900 which I still had in slot 3 booting in windows works now.
  4. Viper69 macrumors newbie

    Apr 24, 2008
    I flashed my eVGA 8800GTS (G92) KO edition card the other day, and it's working perfectly fine in OSX and Vista 64bit on my old MacPro. :D

    The only downside for me right now is that the ROM isn't recognized by NiBiToR, so I'm unable to set the clocks any higher then a stock 8800GT.

  5. Chocomonsters thread starter macrumors regular

    May 22, 2007
    Thanks for your reply.

    Elandrion, sorry to hear that. What windows are you running? Have you tried to reinstall driver? Usually you have to reinstall driver after flashing GPU in windows (at least according to NVflash developer, and I have always reinstalled driver after flashing GPU in windows), but I am sure you have tried that already.

    Viper69, that looks like the card I have. I have already send the file to mvktech guys, so hopely they will update NiBiTor soon. Try using RivaTuner for softclocking your card under Windows. Soft clocking always over-rides the BIOS hard clocking anyways so you can reclock it higher at least in Windows for now until NiBiTor gets updated.

    Thanks for your updates.
  6. Elandrion macrumors newbie

    Jan 13, 2008
    @choco: nevermind what I wrote concerning black screens, after I ripped out the X1900 which was still installed booting into windows was no problem anymore. I just had to install the latest (beta) Forceware drivers to get hardware acceleration.
  7. Chilz0r macrumors regular

    Jul 20, 2007
    Wait, I'm trying to figure out what you guys are saying? So you flashed your 8800GTS 512mb with a 32-bit EFI ROM, put that in your "Early 2008" Mac Pro and it works in both Windows & Mac OS X?
  8. sys0p macrumors member

    Feb 1, 2007
    AFAIK, stream processors are hard coded and not rom dependent, thus the card will use the available 128.
  9. Elandrion macrumors newbie

    Jan 13, 2008
    Not quite. You need to select the correct ROM according to the type of MacPro you have.

    If you have an "Early 2008" MacPro, use the 64bit 8800GT ROM.
    If you have an "old" MacPro (MacPro1,1), use the 32bit 8800GT ROM.
  10. pastrychef macrumors 601


    Sep 15, 2006
    New York City, NY
    Just out of curiosity, has anyone tried an EFI32 8800GT in an Early 2008 Mac Pro? Thanks.
  11. Yarrow macrumors newbie

    Apr 25, 2008
    Moscow, Russia
    Summary: you have success in flashing 8800GTS with EFI32 rom and running flashed card in both OS X and BootCamp WinXP 32Bit. Right?
  12. Chocomonsters thread starter macrumors regular

    May 22, 2007
    Yes, EVGA 8800GTS 512 KO (P/N 512-P3-N845-AR) works well in OS X, XP32, and Vista32. I am not sure on Vista64 yet as I had to take Vista64 off my Mac Pro to reinstall OS X.

    Only problem is that NiBitor does not work for this 8800GTefi32 rom so hard clocking the card back to factory overclocked speed is not possible by BIOS editing. I have tried to OC'd this back to EVGA factory core speed of 678, memory speed of 1944, and Shader of 1728 with NiBiTor, but this card defaults back to reference 8800GT speed. This card can be easily OC higher than 800 MHz core in Windows, but it is limping along at default 8800GT core speed of 600 MHz currently.

    I will try playing around with RivaTuner this weekend for soft OC.


    My Windows are not installed with boot camp (ie, no EFI partition on hard disk), but I did installed boot camp assistance for easy OS switching. But I dont see any reason this should have any bearing on G92 GPU.
  13. tobyg macrumors 6502a

    Aug 31, 2004
    Well I went out and got an 8800 GTS, the KO G92 version (same P/N, 512-P3-N845-AR) and flashed it. Worked fine, for a little while.

    I ran some tests in Windows XP, 3dMark06 got about 12000 at stock speeds, using RivaTuner and setting the speeds up the same as the stock card I got up to 12600, not much of an improvement.

    Anyway, I noticed the fan speed never went up. It's at 30% and 300rpm unlike the 8800 GT at 30% at 700 RPM.

    When I was playing Dirt it ended up crashing and locking up, but before it fully locked up I saw the temperature. Core temperature showed 96 degrees... Celsius! Way too hot! Anyway, back to the 8800 GT and the fan is being controlled fine, temperatures stayed at max 82 degrees at the core, fan speed went up to 50% speed, about 1100 RPM. At least they went up, they didn't go up at all with the 8800 GTS.

    The reason I preferred the GTS is because of the 'advanced' cooling. Unfortunately the controls for the fan are probably part of the ROM, change the ROM and lose the controls.

    I'd like to see if anyone else can test this out. I think this thing is going back to the store unfortunately, sticking with the 8800 GT.
  14. Elandrion macrumors newbie

    Jan 13, 2008
    exactly. the 32Bit part refers to the ROM and not to XP though, as i've said in the post 2 up from yours.
  15. Yarrow macrumors newbie

    Apr 25, 2008
    Moscow, Russia
    Do you have any problem with cooler like tobyg has?

    I think such problem with cooler is maybe specific for eVGA 8800GTS KO Edition only. KO Edition has different cooling system with other GTS'.
  16. Elandrion macrumors newbie

    Jan 13, 2008
    not as far as I can see, even after a few hours of playing WoW I don't get any glitches or crashes, and the fan doesn't turn itself up too. Unfortunately I can't say how hot the card really is, because there is no mac utility which can read the sensor data from the card, and I didn't try any windows game yet.
  17. tobyg macrumors 6502a

    Aug 31, 2004
    Well I put the original ROM back on the card and put it back in my Mac Pro. Under Windows now the fan was at about 450 RPM by default and did go up as I used the card. Played Dirt again, no crashing and the Core temperature on the video card never got over 80 degrees.

    I would NOT suggest using the EVGA 8800 GTS KO G92 version in your Mac Pro.
  18. Chocomonsters thread starter macrumors regular

    May 22, 2007

    RivaTuner works great on my EVGA 8800GTS 512 KO. I've set it to follow EVGA factory OC setting for Fan, core, memory, and shader without any problem.

    Under RivaTuner, you need to set both auto fan setting under low level system tweak and directed fan setting under driver settings

    You can use EVGA setting of 37% min duty cycle, 60 F Temp Min, 85 F Temp High, TOperating 78 F, TRange slope 32, and Temp Low 65 F for auto fan setting. Most guideline suggest using Fan 60%, 80%, and 100% settings for directed fan setting.

    I am sticking with 679 MHz Core, 1950 Mhz Memory, and 1730 Shader OC setting EVGA used (off few MHz from EVGA as RivaTuner can not fine tune speed) which is far conservative OC. I am just worried about Mac Pro generally running hotter than PC. I've pushed this card to over 800 MHz core on PC before.

    Try following RivaTuner Guide. Here is a good guide FYI.


    Once Nibitor gets updated in future, hope we can hard OC in firmware. Until then RivaTuner works fine. I am not sure Voltage setting works well with RivaTuner as 8800 GT 512 firmware runs our GTS at 1.1 V instead of 1.15 V.
  19. tobyg macrumors 6502a

    Aug 31, 2004
    See, that's the problem. I shouldn't NEED to set the fan to anything. I'm not overclocking it beyond the already overclocked specifications, so the fan should be sufficient at the default settings. Unfortunately the fan control is probably burned into the ROM so it's not controlling it properly on the 8800 GTS as it's using the 8800 GT rom.

    I COULD use RivaTuner to control the fan, but I shouldn't have to. What about in OSX? I didn't have anything to stress or monitor the graphics card in OSX so I didn't test that, but my guess is the fan is still not functioning properly in OSX.

    Either way, my advice is still to not use the 8800 GTS in the Mac Pro.
  20. Chocomonsters thread starter macrumors regular

    May 22, 2007
    I agree. You should not have to use RivaTuner at all.

    It is just that we make decision based on our individual needs.

    Apple 8800GT versus PC 8800GT. Cost saving and potential to overclock (as XFX and EVGA provide lifetime warranty) versus Apple support / care. Buy XFX card if needed to as they will replace your card even if it is burned out from overclocking it to death.

    PC 8800GT versus PC 8800GTS. Flash once to Apple reference standard speed and forget it versus overclocking and tweaking with 128 stream processor and dual slot cooler (GTS) versus 112 stream processor and single slot cooler (GT).

    I think if one is uncomfortable with OC, one shouldn't get GTS. Should just get GT as it is plenty fast and runs well. However, if one is going to overclock then GTS is better solution (about $30 more than GT card at NewEgg) as RivaTuner is still require to OC core, memory, and shader speed anyways. Adding fan control setting only requires additional 5-10 mins.

    I figure most people who are willing to flash card at the expense of losing warranty is willing to reclock card back to factory speed. Especially solution requires simple software script using RivaTuner.

    As for OS X, YMMV. I dont have any game that can even stress regular NVIDIA reference speed 8800GT card under OS X. As for professional 3D application under OS X (ie, Maya), 8800GT sounds aweful due to poor driver issue.

    Since using 8800GTS only requires software modification to regain faster factory OC speed, quieter dual slot cooler, and 128 stream processor versus 112 stream processor (abit small gain) makes no brainer for me under Windows.
  21. tobyg macrumors 6502a

    Aug 31, 2004
    Problem there is that you can't forget it. Fan control wasn't working for me even without overclocking. Running at stock GT speeds it was still overheating. I wish the GTS would have worked properly as it is a much better card than even what Apple is selling, but alas it's not fully functional with the Apple 8800 GT ROM installed on it.
  22. Chocomonsters thread starter macrumors regular

    May 22, 2007
    Hi tobyg,

    I just ran 8800GTS without RivaTuner running 8800GT32.rom (reference 8800GT speed).

    Auto Fan control works fine for 8800GTS with Apple 8800GT32.rom.

    I ran Unigine Sanctuary Benchmark for 30 mins to bring up Core temp to 71.3. Fan speed scaled nicely from 30% (base fan speed under 8800GT) upto 42% at 71.3 celsius. According to the Apple 8800GT32.rom setting, the fan speed is 30% upto 68 celsius then scale up 100% fan speed at 108 celsius :eek:

    Obviously Apple wants to run 8800GT hot in order to keep the fan speed / noise down.

    Maybe something is wrong with your card. Try reflashing your 8800GTS card with Apple 8800GT32.rom and try it again. Or you can reflash with original EVGA 8800GTS firmware and test it under Windows to see if fan will regulate. If it doesn't auto regulate with original EVGA 8800GTS firmware under windows, you can RMA for replacement from EVGA under warranty. Good news is that they are very good with warranty replacement.


    Attached Files:

  23. tobyg macrumors 6502a

    Aug 31, 2004
    I've already returned the card.

    As I stated, I did reflash with the 8800 GTS rom and tried it in Windows. The default in Windows with the 8800 GTS rom was like 35% at 450 RPM vs the default in windows with the 8800 GT rom at 30% and 300 RPM. And the fan did increase properly under Windows with the 8800 GTS rom, just not with the 8800 GT rom.

    Sorry, I'll be no help going further with this one as I don't have the 8800 GTS any longer.

    Glad it's working for most of you, I just didn't trust it as it overheated on me and basically crashed when I tried it.
  24. Yarrow macrumors newbie

    Apr 25, 2008
    Moscow, Russia
    Have bought the same eVGA 8800GTS card (512-P3-E841-AR) - everything is OK. It simply works. Many thanks for information.
  25. Frixo Cool macrumors member

    Frixo Cool

    Jun 10, 2004
    Any news about any update of NiBitor?

    I have installed Thermalright cooler on my 8800 (1st gen) and now I would like to try some permanent OC on the Mac side.

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