First Flashed GT120 & GTX260

Discussion in 'Mac Pro' started by MacVidCards, Jul 23, 2010.

  1. MacVidCards Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #1
    OK, now that I have a 64bit Mac, time to fiddle with the cards I was denied before.

    So I gathered a couple 9500GT cards.

    The usual rule of thumb applies here.

    The CLOSER you stay to Apple OEM, the better the results.

    I tried 2 different 9500GT cards, An MSI with GDDR2 and a Jaton with GDDR3. (both 512 Megs)

    NOTE: YOU NEED TO PUT A 256 K CHIP ON TO TRY THIS !!!!

    The Jaton had similar diagonal RAM install compared to MSI which was all right angles.

    Using Nvclock, I discovered that Mac OEM and Jaton GDDR3 had EXACT same clock speeds. (down to 4 decimal places) Flashed'em both and....

    The MSI won't boot, at all.

    The Jaton produces....a lovely, perfect image...from lower port.

    Upper DVI port is dead to world. Even plugging in a DVI to VGA adapter to trigger Hot Plug Detect yields nary a flicker from the thing.

    So, as might be expected, the MDP plug on Mac card has caused issues. Makes one realize how lucky we were with 4870/90. Upper DVI may have been single link, but at least it worked. Not sure everyone would have gone flash crazy if they had ALL been single DVI.


    I will try "sewing" bits of original PC BIOS into Mac ROM, but that is a laborious and rarely happy endinged process. Other than the 7800GT with 7300GT EFI sewn onto it, I have NEVER been able to do this with any Nvidia EFI ROM. Unlike the ATI ROMs, the PC BIOS is more closely woven into the EFI. Must be some "GOTO" and "RETURN" type stuff going on. (Who can help unravel these EFI ROMs? Anyone?)

    I discovered this during my fiddling with a GTX260. Only way to make card work properly in Mac (without Magical Help from Netkas and his bag'o'tricks) was the simplest. Running the bone stock, original Mac GTX285 ROM.

    Did I mention that that card works perfectly? But again, needed a 256K chip installed first. I suspect only certain GTX260s will do this. It is running GTX285 clocks, but shows up with 896 Megs of VRAM and correct number of shader cores, etc. So, a slightly slower GTX285. (for which I paid $100)

    If anyone else wishes to do some experimenting, I'd be happy to put 256K chips on any cards sent to me. (as long as you include return postage and $2 for chip. Another tenner for some Stella is welcome but not expected)
     
  2. CaptainChunk macrumors 68020

    CaptainChunk

    Joined:
    Apr 16, 2008
    Location:
    Phoenix, AZ
    #2
    Very cool, Rom.

    I was thinking about doing a flashed GTX 260 for a while to replace my flashed EVGA 8800 GTS (which really behaves as an Apple 8800 GT with 16 more shaders because the overclocked ROM crashes in Windows games EVERY time). But now I think I might hold out to see what the results will be on flashed GTX 400 series cards when (and if) Apple starts shipping cards with ROMs to extract.

    The GTX 460 in particular is looking very tempting, for the price.
     
  3. MacVidCards thread starter Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #3
    Does Windows id your 8800GTS as an 8800GTS or an 8800GT?

    I actually have a ROM for 8800GTS EFI64 now, would prob help you.

    I haven't released it because don't like lining pockets of AppCrapcanix.

    And since you are in LA, could prob help you out. (just don't make me walk the plank !!!)
     
  4. CaptainChunk macrumors 68020

    CaptainChunk

    Joined:
    Apr 16, 2008
    Location:
    Phoenix, AZ
    #4
    Actually, I'm using Apple's stock 8800 GT ROM on the card. Thus, Windows even identifies the card as an 8800 GT now. I tried using an overclocked version of that same ROM (which had somewhat similar core/memory clocks to a stock 8800 GTS 512). But with that ROM, every Windows game with needing 3D acceleration would crash the whole system (requiring a hard power-down) like clockwork.

    It would actually be interesting to try out your 8800 GTS 512 ROM. The worst that could happen is it not working, in which case I can just revert back to this one, which works fine, though a tad bit slower. PM me if you'd like.

    Thanks!
     
  5. 666sheep macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #5
    ^ Try to flash your GTS with ROM listed in 8800 EFI64 thread. There was ROM for GTS which was combined from EFI32 and EFI64 versions and worked with Win very well.
     
  6. MacVidCards thread starter Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #6

    i imagine he already is

    device id of 88gts can't be rom strapped to 611, can only do 602, which is the one used by efi32 8800gt. the efi64 id is 611. when strapped, results in 601 and neither DOS nor windows allows card & rom to differ

    this is why that rom got written

    and then grabbed up by applecrapcanix and others to sell reflashed 88gts cards for efi64.
     
  7. haveagoal macrumors newbie

    Joined:
    Feb 3, 2010
    #7
    I'd really like to take you up on this offer to do a chip.

    I have a couple of cards I'd like to do something with if I can.

    One of the cards has a Pm25LV512 another has an Atmel AT25F512A and another has an MX MX25L512 which all sound like 64k chips.
     
  8. me2u90 macrumors newbie

    Joined:
    Aug 1, 2010
    #8
    Original Mac GT 120 ROM

    Hi,
    I'd like to try an original rom of a Mac Pro GT 120 with my 9500GT.
    I wonder if anyone could upload it or to help me finding one? :)

    Thanks in advance
     
  9. smchan macrumors member

    Joined:
    Jul 22, 2008
    #9
    Rominator - Are you still mod'ing GTX 285s as well? I've been cruising craigslist and ebay for one but don't really have a steady-enough hand to feel comfortable with soldering. I'll gladly pay for the chip, return post and beer.

    Sam
     
  10. partybymarty macrumors newbie

    partybymarty

    Joined:
    Aug 11, 2010
    Location:
    Hotlanta
    #10
    ROM chip swapping

    Yes, all 25-series EEPROMs that say 512 in the name are definitely 64K. If you still need, I can also swap the ROM chip on your card(s) with a compatible 128K one, programmed with whatever firmware you like.
     
  11. smchan macrumors member

    Joined:
    Jul 22, 2008
    #11
    What would be your charge to swap the ROM and flash a GTX 260 or 285 for me?

    Thanks,
    Sam
     

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