School me on overclocking

Discussion in 'OT Technology' started by Mourning Wood, Mar 26, 2010.

  1. Mourning Wood

    Mourning Wood New Member

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    This is the first computer I've tried overclocking so I don't know too much about it (overclocking), even after doing some research on the subject. The voltages listed below I got from some forum post I found on a google search but they seem to work well.


    The CPU is a Core i7 920 running at 3.81ghz. ASUS P6TD Deluxe motherboard. These are my temps after two hours in Prime95.

    [​IMG]


    Using the following settings:

    Code:
    Ai Overclock Tuner => Manual
    Intel Speed Step Tech => Disabled
    Intel Turbo Tech => Disabled
    CPU Ratio => Auto
    BCLK Freq => 191 (= 3810 MHz)
    PCIE Freq => 100
    DRAM Freq => DDR3-15xxMHz
    UCLK Freq => Auto
    QPI Link Data Rate => Auto
    
    Voltages
    -----------
    CPU Voltage => 1.25
    CPU PLL Voltage => 1.80
    QPI/DRAM Core Voltage => 1.25
    DRAM Bus Voltage => 1.64
    CPU Differential Amplitude => 800mV
    
    all other voltages to Auto
    Would it be safe to assume that I should be able to do 4ghz without much trouble or heat increase? It's only 190mhz more.

    Also, what is considered an acceptable temperature for maximum CPU load? I'm also concerned about the life of the chip if overclocking it is going to shorten that life considerably.
     
  2. Mourning Wood

    Mourning Wood New Member

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    Come on, surely some of you know more about this than I do :x:
     
  3. deusexaethera

    deusexaethera OT Supporter

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    Honestly, overclocking is old news. The limiting factor in performance these days is either a lack of RAM and/or a hard drive that's too slow. The hard drive responds to commands about a 100,000x slower than the CPU and RAM. That's why SSDs are the hot shit right now; they're still not as fast as RAM, but they are a hell of a lot faster than normal hard drives.
     
  4. lowfat

    lowfat 24/Mac/SciFi/PC Crew OT Supporter

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    Depends on your usage. Overclocking my CPU from 2.66GHz to 4.2GHz gained my 70% increase in speed on what I use it for.
     
  5. DIABLOS

    DIABLOS New Member

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    Depends on the usage entirely a very blanket statement you have made..

    For games, yes it is a waste but for rendering or encoding it is very much worth it.
     
    Last edited: Mar 28, 2010
  6. DIABLOS

    DIABLOS New Member

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    As long as you're under 80c when running prime then you'll be fine. You won't shorten the life of the chip unless you use excessive volts which impossible to do on air anyway as the chip will over heat and crash which will force you to lowe tthe volts anyway.

    Set the volts at 1.35 for both the the core volts and the QPI test for stability and gradually lower the volts until it is as low it will go and maintain stability.
     
    Last edited: Mar 28, 2010
  7. Mourning Wood

    Mourning Wood New Member

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    Do I always keep these voltages the same?

    Also, is it safe to run a stress test while I sleep? What if it locks up two hours after I've gone to bed and sits there for another six? That won't damage anything?
     
  8. CodeX

    CodeX Guest

    School you eh?

    Processor cores are made in batches, on large "wafers", and individual ones are cut from the those wafers, much like paper money is made on large sheets and are cut to their individual sizes. Because of subtle variations in this process some cores end up being able to handle higher clock speeds than others. Often times it is more cost effective to sell cores capable of higher speeds as a lower speed by artificially limiting it through various means. Even if that was not the case with your specific processor it is certainly artificially capped below it's potential, for reliability reasons and because it is just unreasonable to test each and every core produced for it's maximum clock rate.

    Now, this is where overclocking comes in. If you are lucky you have a higher performance part than what was sold to you, and can unlock that potential. That is the best case scenario but like I said even if that is not the case there is almost certainly some improvement to be made. To overclock a processor you either increase the front side bus speed or you increase the processor multiplier, which multiplies the front side bus speed to get the processor frequency. You have less control with the multiplier than you do with the FSB speed, in terms of step sizes, but if you adjust the FSB speed the north bridge chipset and RAM have to be able to handle the increased speed, because they will be effected as well, whereas the multiplier will only effect the processor clock.

    Now, here is where voltages come into play. Say you hit the limit and your computer becomes unstable with a certain clock speed. One thing you can do is increase the CPU or memory voltage. Memory voltage can be increased if you are limited by the memory speed after adjusting the FSB clock, or CPU voltage can be increased if you are limited by the CPU after adjusting either the FSB speed or the processor clock.

    The reason increasing the voltage helps is because the faster the clock speed the more difficult it is for the internal hardware to detect transitions on hardware pins (which is how computers work). By increasing the voltage you increase the "pressure" on the signal, so that when a state change occurs on a pin it "snaps" into position more quickly. In addition to this the signal level between a low signal and a high signal is increased, making it easier to detect and less likely to be lost due to digital noise on the line.

    However, there is a draw back. Increasing the voltage increases the "friction" caused by resistance in the circuit. This causes higher thermal output than normal and it becomes more and more difficult to maintain the temperature of the component, eventually creating a thermal runaway condition where the part fries.

    So, increase the FSB until your memory craps out, increase the memory voltage until you can no longer keep it cool, increase the multiplier until the processor craps out, increase the processor voltage until you can no longer keep it cool.... done.
     
    Last edited by a moderator: Mar 31, 2010
  9. CodeX

    CodeX Guest

    Or, that is how it used to be, when it couldn't be done by idiots... I remember drawing a connection between two jumpers on my old slot Athlon with a graphite pencil to unlock it... after cracking the case open with a screwdriver while almost pissing myself

    Now, you run a program and it automatically does it for you and figures out your maximum potential with one mouse click...
     
  10. CodeX

    CodeX Guest

    Also, be sure you know how to clear the CMOS on your motherboard before you try any of this...
     
  11. 5Gen_Prelude

    5Gen_Prelude There might not be an "I" in the word "Team", but

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    Calculating Pi?
     
  12. deusexaethera

    deusexaethera OT Supporter

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    :rofl:

    Probably encoding, based on what others in this thread are saying. I guess that's a valid use for overclocking, but I think I'd rather do that with an older single-core machine that I'd only boot up when I needed to encode something, and just use a newer multi-core machine for daily tasks.
     
  13. Mourning Wood

    Mourning Wood New Member

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    :bowdown: thank you!
     
  14. Mourning Wood

    Mourning Wood New Member

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    I remember reading about how to do that but never had the balls to :rofl:
     
  15. bowrofl

    bowrofl New Member

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    So overclocking is pointless for games now? Trying to figure out ways to squeeze some juice out of my gaming desktop that has a Q6600 2.4 Ghz CPU. :hs:
     
  16. deusexaethera

    deusexaethera OT Supporter

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    So much of games' processing needs are graphics and physics related that it hardly matters what your CPU is anymore; all that stuff is handled by the video card nowadays. (nVidia started using spare GPU power to compute physics interactions about a year ago, IIRC.) The most CPU-intensive part of a game anymore is handling the network traffic for MMOs or just loading the environment into RAM.
     
  17. CodeX

    CodeX Guest

    OC'ing the CPU is mostly useless for gaming... but OC'ing the GPU or video memory is still very useful.
     
  18. JustJeff

    JustJeff www.youtube.com/thisisjustjeff

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    GPU's will find their ways into CPU's within the next 10 years. :)

    They are number whores... they will do a lot of simple computations very fast. CPU's are more of the "Smart core"

    Overclocking is useless... unless you are doing some demanding graphics rendering or the like. Don't waste your time/kill your processor on it. Hardware nowadays is much more reliable and doesn't need to be fussed with. Once SSD's make a run (hopefully they will in the next few years), you will see drastic increases in performance. I'm actually excited to see some of these newer devices that are "smart phones" that do everything you can imagine... They even brew you coffee!!

    But anyway... I would say only for the learning experience do what CodeX has said to do... otherwise don't mess wiht it :p
     
  19. DigiCrime

    DigiCrime If Only!

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    Mine blue screens to much even with a slightly overclock FSB. :hs:
     

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