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P4 2.8Ghz HT Carputer setup.

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  • P4 2.8Ghz HT Carputer setup.

    Hi, I have been pondering in getting this thing going along time ago, but just have been caught up with other things, but now it's time to get this done, hehe.
    I have a P4 2.8 HT, 512mb ram, 120gb HD and intel motherboard.
    I know I should probably use something less powerful for a in car computer but I really have no use for this PC.
    So if you guys can help me out with a few questions I would greatly apreciate it:
    What do I need to get to power this computer? A higher output alternator? Or just a XX watt power supply/converter? Name or link of where I can get one please.
    Is there someone that sells the complete wire kit to connect the cpu to the DVD/CD rom that will be in the dash along with the Xenarc 7" screen all the way from the trunk? - Battery is in the trunk BTW.
    What else will I need besides the shutdown controller being that I have the cpu complete?

  • #2
    Inverter + SDC. Go to the mp3car store.


    • #3
      I looked at the calculator and for my setup I'm going to need:
      Required CPU Power : 85.50 W
      Total Required PSU Power : 133.37 W

      So which power supply will power this?
      Will I need a higher volt alternator?


      • #4
        This is the last time I'm explaining this. It will go into the FAQ Emporium as soon as I'm done, with additional information that I'll leave out for your benefit.

        The main factor in determining power needs is your CPU. Some CPUs draw lots of power, namely P4 and Athlon64 units. The CPU is the biggest variable in systems, as far as power consumption.

        Look up your CPU on Chris Hare's PROCESSOR ELECTRICAL SPECIFICATIONS page. He lists the electrical specs of just about every CPU produced in the past ten years or so. Look at the Max Power Dissipation column. That's the peak power usage of the CPU under heavy load. Using this figure in your calculations will allow power overhead for the CPU to perform any tasks you throw at it without choking off your power supply.

        Now that you know the max power draw of your CPU, you need to know how much power the PSUs provide on the 12v rail. The 12v rail is the one that will provide power to the CPU. It's stepped down to 1-2w (typically) with more amperage so the CPU doesn't burn up. There's circuitry on the motherboard for this.
        Typically, the PSU will tell you how many amps it will output on the individual rails. To calculate wattage output, you multiply amps by volts (A x v = w). If the wattage output of the PSU is less than the max dissipation for your CPU, it won't work.
        Some will argue that the PSUs put out more than they are rated for, blah blah blah. This may very well be true, but do you really want to gamble that a $100 PSU will work for your desired setup based on a couple of watts difference?

        The other thing you need to consider is other 12v devices. There aren't that many. 3.5" HDDs, full-sized optical drives, case fans, external audio like a Creative SB Audigy NX, possibly an LCD screen, etc. There are other power calculators that will give you power usage estimates for these devices.

        Let's say you want to use an Opus 150w PSU with a P4 2.8C CPU. If you look up that CPU on Chris Hare's page, you can see that the max power usage is either 68.4 or 69.7w, depending on flavor. Let's call it 70w for simple math. ALWAYS ROUND UP!!!!
        So you look up the specs for the Opus 150w and it says that the output on the 12v rail is 5A. 12v x 5A = 60w.
        You'd get 60w out of the Opus PSU and the CPU requires 70w. It's not going to work.
        Have you looked in the FAQ yet?
        How about the Wiki?

        Under normal circumstances, a signature would go here.


        • #5
          Thanks for the help.
          I went with a less power hungry PC.


          • #6
            I have a similar system. I have a intel 2.6p4 w/ht and trying to load up the os for the first time. Im using an external dvd/cd bunner from panasonic in a case to load the os. I changed the things in the bios so it loads from the external drive via usb. The problem I have is that it tell me on the screen to load :boot media for the device! Im using the micro-atx board(intel d865glc). Ive disabled all othe devices except the cd drive. The panasonic uj-845 doesnt have a dos driver. I need help bad!


            • #7
              Nice threadjack.

              Your request for assistance generates more questions than answers:
              1) Why do you need DOS drivers? Look in your BIOS for an option to enable USB boot so you can boot from the external USB drive.
              2) For installing Windoze, I'd recommend connecting an IDE optical drive, just for the simplicity of it. It can alsways be removed later on.

              Next time you have an issue, either create a new thread or post in a thread that is at least related to your problem. Hijacking someone else's thread is generally frowned upon in forums.
              Have you looked in the FAQ yet?
              How about the Wiki?

              Under normal circumstances, a signature would go here.


              • #8
                Originally posted by Soup Nazi
                Thanks for the help.
                I went with a less power hungry PC.
                You could always underclock the processor so it uses less power...a happy benefit of which is it also runs cooler. Of course, your motherboard should have a bios that allows you to lower the clock speed (and perhaps drop the voltage a tad too). Problem is: you'll have to underclock fairly heavily as you can't be sure how much power you're saving.
                EPoX mATX SocketA w/onboard Geforce4MX / 512MB PC2700 / AthlonXP 1600
                Lilliput / DVDrom / Opus 150W / WD 3.5" 160GB / SB Audigy NX
                XP home / Road Runner / iGuidance 4.0