NVIDIA's trick to boost the GeForce 9600GT

Discussion in 'Frontpage news' started by cowie, Feb 29, 2008.

  1. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    Last edited: Feb 29, 2008
  2. Hilbert Hagedoorn

    Hilbert Hagedoorn Don Vito Corleone Staff Member

    Messages:
    31,042
    Likes Received:
    710
    GPU:
    AMD | NVIDIA
    The reference clock is being pulled off the PCIe bus ..

    Big deal ?
     
  3. roguesn1per

    roguesn1per Ancient Guru

    Messages:
    9,511
    Likes Received:
    0
    GPU:
    GTX580
    lol exactly...

    Its not gona improve the performance more than what overclocking does...cause its the same thing.

    Apart from the fact that raising the PCIE bus can cause problems.
    And this doesnt Tell us why its Just as fast as a 8800gs...
     
  4. Hilbert Hagedoorn

    Hilbert Hagedoorn Don Vito Corleone Staff Member

    Messages:
    31,042
    Likes Received:
    710
    GPU:
    AMD | NVIDIA
    Let me elaborate a little, as Unwinder and yours truly have been hunting this since three weeks (working on the new Rivatuner).

    I was actually the first to notice that the 27 MHz crystal only was used for the memory and not longer the core, reported it back to NV, did not get a valid answer back. That by itself is unusual.

    Two days ago I got word back from Unwinder where he concurred that the primary GPU clock is now pulled off the PCIe bus, and no longer of the 27 Mhz crystal on the PCB. That PCIe clock is 100 MHz. NVIDIA fires a divider of 4 on it and that way achieves a 25 MHz core frequency that is multiplied to the final clock-core frequency.

    So why it's unusual to pull the 25 Mhz clock from the PCIe bus, it's nothing special either. There's no feedback data from the GPU towards the PCIe clock, thus overclocking at driver level will never influence the PCIe clock.

    Increasing the PCIe bus itself, would increase the GPU clock though and thus performance though.

    So a little unusual .. yet a clock is a clock. I find the question as to why memory and the GPU clock now are separated a way more interesting one ;)
     

  5. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    sry you posted first
    exactly it may cuase problems.
    plus if you happen to run some mb's certain controlers will let you run higher pci-e speeds true right?
    plus the fact your sorta clueless on how high your clocking the card right?
    busting you head open trying to find out why you system wont boot.
    plus its new and i hate change if not for the better? is it for the better?.
    but boss you know best and i geuss i got carried away
    man seasonal jobs.. i need a life lol

    than what about shaders?
    and how to oc these cards in software?
     
    Last edited: Feb 29, 2008
  6. Hilbert Hagedoorn

    Hilbert Hagedoorn Don Vito Corleone Staff Member

    Messages:
    31,042
    Likes Received:
    710
    GPU:
    AMD | NVIDIA
    Nono .. don't get me wrong bro. I'm just trying to elaborate a little as I it looks like some sort of dark secret is revealed now. While in fact it's nothing more than a reference clock being pulled from a new location.

    Any modern mainboard has the PCIe bus locked at 100 Mhz. And the ones that do run faster really are merely a few mhz higher (ASUS auto clock etc), hardly noticeable.

    And overclocking the card will remain the same, makes no difference.

    I had a discussion about this topic this afternoon with unwinder, and my last words where "Gosh, we are such nerds". Because we spend 3 weeks hunting this abnormality down, and then I realized .. this is not a big ****** It's just a ref clock pulled from another location.
     
  7. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    well ok
    but say my marvel controler on my dfi t2r will let my pci-e bus hit almost as high as an nv mb,and other craps out at 105-107area?
    i sometimes push them that high cus i add volts to cards
    and not nerds boss your PRO'S
     
    Last edited: Feb 29, 2008
  8. roguesn1per

    roguesn1per Ancient Guru

    Messages:
    9,511
    Likes Received:
    0
    GPU:
    GTX580
    As Such why would you Have you pcie over 100 anyway??

    Any "overclocker" knows to lock it at 100 cause it causes problems any higher.

    So if you dont overclock, then its not a problem....And if you do overclock and dont lock the pcie then its your problem
     
  9. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    hey corrupting drives gives me pleasure
    ok i have my reasons to do that sometimes
    ever heard of linkboost?
    ever try to take non 6pin cards that are modded for a spin?
     
    Last edited: Feb 29, 2008
  10. Hilbert Hagedoorn

    Hilbert Hagedoorn Don Vito Corleone Staff Member

    Messages:
    31,042
    Likes Received:
    710
    GPU:
    AMD | NVIDIA
    If that's the case then if and everything remains stable, you'll have a slight overclock.

    If GPU is (600 MHz / 25) x (107MHz / 4) = 642 MHz.
    Worst case scenerio .. PCIe clock needs to revert back to original clock (100 MHz). But why overclock the PCIe lanes anyway ? Nobody does that as there's plenty of bandwith already.
     

  11. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    true so useing that formula you can keep track ok
    free benchmark points cus i'm a benchmark whore sometimes
    sry if i acting rash boss
     
    Last edited: Feb 29, 2008
  12. roguesn1per

    roguesn1per Ancient Guru

    Messages:
    9,511
    Likes Received:
    0
    GPU:
    GTX580
    it doesnt give you "free" anything

    becuase its raising the GPU clock.

    So the Performance increase is not free because you had to overclock to do it :p
     
  13. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    no dude lets not say the 96
    i was giving reason why i push the pic-e lanes sometimes for higher bench marks lol
     
  14. Hilbert Hagedoorn

    Hilbert Hagedoorn Don Vito Corleone Staff Member

    Messages:
    31,042
    Likes Received:
    710
    GPU:
    AMD | NVIDIA
    Oh and Cowie, I missed one of you earlier questions. But overclocking remains the 100% same, it still happens at driver level.

    The GPU picks up the 25 MHz reference clock, and from there on everything is managed at VGA level / drivers.
     
  15. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    ok got ya.
    that was my concern
    you can close if you feel like boss
     
    Last edited: Feb 29, 2008

  16. Skiddywinks

    Skiddywinks Ancient Guru

    Messages:
    4,562
    Likes Received:
    0
    GPU:
    Asus Matrix 285
    *reads links*

    *reads topic*

    WHOOSH. Way over my head -_-

    Good thing it doesn't sound important then!
     
  17. anwaypasible

    anwaypasible Banned

    Messages:
    904
    Likes Received:
    0
    GPU:
    evga / 7900 GTO / 512mb @ 676/1554
    lol.. i'd have a clock of 949.75mhz
     
  18. Alexstarfire

    Alexstarfire Ancient Guru

    Messages:
    8,316
    Likes Received:
    0
    GPU:
    GeForce 9800GTX+ @ stock
    I think the whole point of this was to say that unless you knew about LinkBoost and how the 9600GT computes it's core clock you could unknowingly compare an OCed 9600GT to a stock version of a any other video card, while thinking that they were both at stock speeds. Course, this would only happen to amateur benchmarkers and OCers, but still. No advanced OCer would dream of doing anything manually, so the PCIe bus would never change without his knowledge. Also, another problem comes in with how RivaTuner and GPU-Z report the core clock speed. While RivaTuner correctly shows the core clock speed when you go into the hardware monitor, it reports a false clock speed when going into the driver settings. Not a big deal to advanced users, but the less experienced may be fooled into thinking his card is at stock settings, when in fact it's not. The less experienced may use auto-overclocking in the BIOS to OC the CPU. If it happens to be an nVidia board that automatically increases the PCI-e speed, then the video card may inadvertantly be overclocked all the while the user has no idea, since he likely wouldn't use the hardware monitor in RivaTuner. It seems to me like it's a ploy to dupe/fool the less experienced into thinking something that may not be true.
     
  19. cowie

    cowie Ancient Guru

    Messages:
    12,828
    Likes Received:
    23
    GPU:
    GTX
    ding ding ding you win a cookie
    i'd would just like to know before hand.
    but i think that i know why they did not
    the competition

    btw if you aint pushing your pci-e you aint tryin'
     
    Last edited: Mar 1, 2008
  20. Alexstarfire

    Alexstarfire Ancient Guru

    Messages:
    8,316
    Likes Received:
    0
    GPU:
    GeForce 9800GTX+ @ stock
    It's not like there is a reason to push my PCI-E clock speed. Won't make anything go faster, it's just make it more unstable.
     

Share This Page