PCI latency? a Q for Gurus

Discussion in 'Links' started by Emile, Jan 6, 2005.

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  1. NowhereMan

    NowhereMan Ancient Guru

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    This tool doesn't work on my motheroard. Computer just hangs (new or old version). Any other tools out there?
     
  2. Phalkon30

    Phalkon30 Ancient Guru

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    IIRC, this tool is for AGP only cards. Looks like you're on PCI-E. I really think that the first post should be edited to reflect this...
     
  3. BlackZero

    BlackZero Ancient Guru

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    yeah makes my pc hang also, I do have another tool same thing but an older version and works absolutely fine heres a link to the thread where it's posted:

    http://forums.guru3d.com/showthread.php?t=247805&highlight=ltcycfg
     
  4. allenaudio

    allenaudio New Member

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    Download on CD?

    Greetings.

    New here with a question.
    I use E-mu 1616 with Reaper software for recording. I would like to check the latency settings of my Emu card. The laptop I use for recording I do not put on line.
    When I burn the software on to cd it doesn't run?
    I get error messages.
    Do I need to be online to run this software or is there a way to run this after it is on a cd?

    Thanks
    Doug
     

  5. RED X

    RED X New Member

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    great site, loads of info,got fs2004 installed,on vista,but got the same probs, as like these others guys get, stuttering,because my video card is oc,is that gonna cause me any probs, ive bought the lat down to 64,but it still stuttering,in game,but not as bad, is it better to go up or down on the lat? ,infact the only thing i see ,with a lat number is the bus host controllers, on 32,is that normal?and the pci standard pci -to -pci bridge, that was set on zero too,that is the video card to change the lat,allso games like bro in arms,cod5,crysis all run brill,so should i only reset everytime i play fs2004 ? any help ,would be great ,ty
     
    Last edited: Jan 26, 2009
  6. AnthraxPants

    AnthraxPants Banned

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    As posted earlier by Phalkon30 and others, PCI Latency tool is aimed at AGP based motherboards. A latency of 32 is quite normal for some hardware, though you may see some system components with a latency of 0. You should never try and force any latency value to 0, in fact you should only alter latency values if you have a firm understanding of what you are doing.

    Video cards and sound cards will often show up as having a latency of 32 on an AGP motherboard. That is usually a good value as devices operating on the PCI bus usually default to a value of 32 so they all behave and play along nicely with one another. The bus host controllers operate with a latency of 32, so if devices like video and sound cards can operate with the same latency, then they should be working nicely in sync.

    Some of the older AGP graphics cards like the Nvidia 6800GT and its predecessors used to show up as having a latency of something like 264 in the PCI Latency Tool (or some rather slow value like that, I can't quite remember but it was a rather big latency value). Much nicer to have that old graphics card operating with a tighter latency of 32 instead so that you could ensure it was operating as responsively as the other devices using the PCI bus.

    In some situations, problems with sound cards on AGP based systems could be fixed by setting the sound cards latency to 64. A looser latency for the sound card could help remedy problems with audio, such as popping or crackling sound from certain models of creative sound cards. If you use MIDI with audio programs you may want to leave the value at a lower latency of 32 and try and solve the sound issues by trying updated drivers for the sound card first. However for general playback of audio, if the sound card behaves itself a lot better with a latency of 64 then you are better off sticking with it.

    For the PCI Latency Tool to work you need copy it to a location such as your system drive, usually the C:\ drive. You can create a folder for it there (C:\PCILatencyTool for example) and run the tool from that folder. Once you change a latency value for either a sound card or a video card with PCI Latency Tool you need to click apply and then restart Windows for it to take effect. There is no need to alter the latency for any other type of device and no need to try and change the latency settings if you have a PCI-Express motherboard.
     
  7. BlackZero

    BlackZero Ancient Guru

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    AnthraxPants,

    In this case it's the other way round, a higher pci latency translates to a device taking up more time on the pci bus, hence better responsiveness at the expense of other devices with lower pci latencies. Ati graphics card drivers in particular were known for programming the pci bus to allow maximum latency to ati graphics cards (248) and this could lead to other pci devices such as sound hardware being choked for pci bandwidth.
     
  8. Pill Monster

    Pill Monster Banned

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    Um, I'm pretty sure that's what he said....

    btw congrats to you guys for bringing a well and truly dead thread back to life :p
     
  9. BlackZero

    BlackZero Ancient Guru

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    No, he said devices with lower pci latencies are more responsive.
     
  10. Pill Monster

    Pill Monster Banned

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    Ok yes I see he did say that, but his point was still valid - that the default latency settings on ATI (and Nvidia cards btw), were set ridiculously high and ended up hogging the bus all the time.

    I think you guys agree with each other there. And I agree with you both....;)

    So can we all agree on which point we are agreeing on? :p
     
    Last edited: Feb 4, 2009

  11. BlackZero

    BlackZero Ancient Guru

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  12. Pill Monster

    Pill Monster Banned

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    ^agreed hehe
     
  13. Spathi

    Spathi Master Guru

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    I use guru pci3 then copy these over top...
    http://newbling.net/wtf/tools/LtcyCfg.zip
    They are a few days newer and show my ATI 38xx AGP card.. (the 3 ones on Guru don't)
    To copy over windows\system32\drivers\LtcyCfgWDM.sys you need to stop the service

    (32-bit only I am afraid as I don't know where I got them from) they are 29/12/2005 so maybe you could track down 64 bit ones.


    [​IMG]

    What matters is getting 256 spit between devices on the same BUS in a way so the chances of 256 being exceeded are low if many devices try to use their full allocation. The more you give the AGP or PCI card the better (UNLESS it has sound on the same bus).. so normally for AGP 255 is the best setting... unless the card has HD sound, then... 224/32 or 192/64

    Bus 0 is handled by the south bridge... so just leave them alone.. or turn south bridge devices off in your bios you don't use.

    PCIe does not use a PCI bus, so it does not matter for new boards.

    cheers
     
    Last edited: Feb 16, 2009
  14. ShivanSpS

    ShivanSpS Member Guru

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    There is ANY way to make this work under Vista x64?

    We just dicovered in the Egosoft X3:TC forums, that setting the max pci latency will greatly improve game performance, even with pci-e card it seems.

    And my damn mb dont have the option to change that.

    nevermind...

    it work on vista x64 installing it with UAC off AND ALWAYS booting up the system in "Disable driver signature enforcement"
     
    Last edited: Apr 9, 2009
  15. Shroomalistic

    Shroomalistic Member

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    is there any program that will just let you check your latencies with out modifying them. I cant get the PCI Latency tool to work at all. Im on vista 64bit also. I tried the Disable UAC and Disabling driver signature.

    the error I get is
    Failure to initalize Config Space access!
     

  16. Feneeth of Borg

    Feneeth of Borg Member Guru

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    This is because the concept of PCI latency timers seem to be misunderstood by you, because each one is the amount of cycles the device gets until the PCI bus moves on to the next, so turning down all but the video card would end up with incredible framerates, but struggling audio and networking. Remember, Balance is the key.
     
  17. amablue

    amablue New Member

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    I got PCI latency tool, but it doesn't show my video card on the list of devices. I have an nvidia 8800, but all I see on the list is my wireless adapter and a bunch of Intel stuff. Anyone know why?
     
  18. morbias

    morbias Don TazeMeBro Staff Member

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    Because PCI is not the same as PCI Express.
     
  19. ForgedReality

    ForgedReality Master Guru

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    Tried installing the latest version of this tool on win7 64bit, and Windows tells me it won't let the program load a driver because it isn't digitally signed.
     
  20. Feneeth of Borg

    Feneeth of Borg Member Guru

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    Sorry but you are incorrect, its not like ram latencies in which its simply lag. If you turn down the agp controller your performance will decrease, period. Don't make claims that its helping if you don't have proof or even logic to defend your claims, look at the pci bus page on wikipedia, and my performance agrees with it, 248 worked the best for my radeon 9800 and my 2600 (agp).

    There is another way to improve performance, by disabling unused devices, ide controllers, usb controllers, card readers, modems, etc, go into device manger and select "view by connection" disable pretty much everything that doesn't have anything connected to it. On my laptop, I reduced the devices fighting for bandwidth form 17 to only 12, considerable gains in networking, graphics, even my mouse was higher framerate.

    Most sound cards can handle 32, I suggest 64 for network adapters, and 248 for agp bus. There is a reason its set this way from the start, and its not because its the most stable.
     

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