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Hardware Review: M3-ATX Power Suply

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  • Hardware Review: M3-ATX Power Suply

    Recently I've upgraded my system. My reliable Epia M10000 was replaced with a Biostar MB with an intel celereon M440 processor. Also to power this I needed a bigger PSU then the M1-ATX I had before. So the new system is powered with a M3-ATX power suply.

    The reason I choose the M3-ATX was for it's small size. And small it is. When I recieved it I couldn't believe how small this thing really is. And is this supose to give me 125W were my first thoughts.

    When installing it simply snaps on the ATX power connector. No wires are needed to make the connection between the power suply and the ATX connector. This is it's main advantage. There is no cable mess in your case when using this power suply and it can be fitted in very small cases.

    It has a build in start-up/ shutdown controller that can be set to a few different settings by the use of jumpers. The one most used is jumper setting one wich turns on power after 2 seconds after ignition, shuts down windows after 5 seconds after ignition is turned off and completely shuts down after another 60 seconds giving the system time to shut down.

    Also it has a build in "anti thump control". Simply connect this wire to your amplifiers remote and there are no loud pops when starting/shutting down your system.

    Once connected to my test bench and flipped the switch to simulate ignition I immediatly noticed the long time it needed to start up the system. Altough the manual says 2 seconds, it almost takes 10 seconds before the system fans start to turn and POST is started. I found this a really long time compared to the M1-ATX I had before wich was significantly faster. When setting up my system I didn't found any problems using this small PSU. I am using a 3,5" Western Digital Caviar HD and also powered my external CD rom and a TFT screen with it and it seems to have enough power to do this. After my system was setup properly it was time to put it in the car and this is where the problems began.

    I drive an 1996 BMW 525tds. This is an older type of diesel engine and it needs to glow a couple of seconds before the engine can be started. Wen glowing, the glow plugs are using so much power that the cars electrical system drops below 12V during this time. And when the voltage is lower then 12V the M3-ATX doesn't power the system. It's also mentioned in the manual. Is it a safety feature? Is it a flaw? I don't know, but it's really anoying. Also after the engine is started and the voltage is rised to 13,8V the M3 doesn't power the system anymore. I have a kill switch installed that cuts the main power of the PC but also when turning this off and back on again the system isn't powered. The M3 seems to need the ignition puls after it recieves main power to power up unlike my M1-ATX wich also started after killing main power and putting it back on. For me this is a major flaw!

    The only option left is to turn the cars engine off, turn on ACC but not the ignition so the glow plugs don't draw power yet, wait until the system is powered and then start glowing and starting the engine. This really isn't a good solution. Also when starting the engine when in POST it seems the M3 hasn't enough power for the 3,5" HD because when I do this I often get a disk boot failure. So I actually have to wait until windows is loading to start the engine. This seems like forever when waiting in your car to drive away.

    The anti thump circuit also isn't as good as on the M1. There still are pops. They are not very loud but they are there. With the M1 there was nothing. Also after the system has shut down the amplifier turns back on again for the remaining 60 seconds the power suply waits until shutting down completely drawing a lot of power during this time.

    So my conclusion is that this is not the best PSU I've seen. Compared to the very reliable and stable M1-ATX this really isn't a good PSU, period. Maybe in a petrol driven car problems aren't that big but still... I certainly wouldn't reccomend it if you drive a diesel powered car, even a modern one. If you don't really need the small size and power I would definatly recommend the M1-ATX over this one. I have no expierience with the M2-ATX but I guess that one also is a better choice then the M3-ATX.


    -Small Size
    -No cable mess
    -Has build in startup/shutdown controller
    -Has anti thump system


    -Really needs 12V at startup. (Not available with diesel engines)
    -Doesn't really survives engine cranks all the time.
    -Takes a long time to start up.
    -Anti thump isn't very good
    -PC can't be restarted by killing main power and putting it back on. It needs ignition pulse again.
    -Turns on amp again after windows has shut down for about 60sec.

    Note. These tests were done right after I replaced my battery with a new Bosch Sliver Plus 100Ah one so I'm sure the battery is good condition. The M1-ATX worked just fine, even with the old battery.
    BMW 525tds -Biostar I94GM-I4 -Celeron M44O 1,86GHz, M2-ATX, 1Gb, 320GB -HQCT RDS tuner -Creative Extigy -iBus controller -Lilliput 7" touchscreen -DLS Ultimate A7 amplifier -Focal 130K, 130V, 27V2 speakers

    Bezel Worklog-My Install -iDrive F01 RR Skin

  • #2
    Super Review

    That a very nice review, very very helpfull, i was thinking of getting this to replace my M2-ATX due to space constraints in my new car, after reading this am having second thoughts especially as i have just bought a Colt Diesel.

    Thanks Again


    • #3
      I have to disagree, based on my experiences so far....
      I do not drive a diesel though..

      I replaced an opus 90 with this unit.

      Works great, I did not notice the slowness booting.
      I am however running a laptop HDD and the Xenarc using this unit.

      XM/HD Radio (external power)

      Turns off like it should and turns on like it should.
      I am completely amazed at how well this works, so two thumbs up from me.
      EPIA M10000, 512 Ram, Opus 90, GPS, XM, 7" Xenarc, Pioneer HU
      Installed & Working....
      Custom enclosures
      Newbie Guide


      • #4

        Now I've ran the power supply directly to the battery and it works a little better but still far from perfect.

        Shutting down is no real problem except for the fact the amp stays powered for about 60 seconds after shutting down. This is not a big problem but my heavy amp still draws a lot of power when idle during these seconds and I concider this as a flaw.

        Startup though still has problems. I measured the voltage on the battery (a brand new one as I said before) when glowing the engine and it is about 11,8V. The manual of the M3 specificly mentions it NEEDS 12V at startup. I don't have it and there is no way of having it in my case and many other diesel engines.

        With the new wire from the battery it seems to survive engine cranks better I must say. But then I have to turn on ACC wait until the system starts, turn on ignition and glow, and after that start the car. This takes forever!

        So now I use a switch on my ACC wire to make the computer start after the engine is started. This is the only way to make it start reliably. So far for making it start with the turn of the key. I have no experience with an opus but I never had any problems with my M1-ATX.

        Also the small amplifier pops maybe nothing serious for most users but the M1-ATX has no pops at all!

        So I still don't recommend it to use in a diesel powered car. It's quite possible that on a petrol powered care you won't experience any problems at startup ever because the voltage never drops below 12V (if you got a good battery) so if you have petrol car you probably can give the M3 a go but after what I've experienced with it compared to my M1, I would never buy it again. Specialy because there are two better alternatives that cost about the same as the M3 and those are the M1 and M2.

        The M3 could have been a reasonably good PSU if there wasn't the need for 12V at startup. Now it just isn't. That's my opinion.
        BMW 525tds -Biostar I94GM-I4 -Celeron M44O 1,86GHz, M2-ATX, 1Gb, 320GB -HQCT RDS tuner -Creative Extigy -iBus controller -Lilliput 7" touchscreen -DLS Ultimate A7 amplifier -Focal 130K, 130V, 27V2 speakers

        Bezel Worklog-My Install -iDrive F01 RR Skin


        • #5
          I was just linked to this page 3 hours after purchasing the M3.. i have a petrol car and will let you know my findings in a weeks times when it arrives.

          i do hope that it works without any hiccups.

          post back soon
          Originally posted by ClockWorK
          Remember, as soon as you make something idiot-proof, they will come out with a better idiot.


          • #6
            A little update:

            After only a month or so, the M3 died on me. It simply didn't start anymore. Tried more then 50 times flipping my ACC kill switch. When standing still witout engine, standing still with engine, while driving,... The darn thing just wouldn't turn on the PC anymore! Even with voltages as high as 13,5V!

            So now I replaced it with an M2 and all my problems are gone. Never have to use the ACC kill switch anymore. It starts up like it should, shuts down like it should and this without any amplifier pops at all just like my M1 used to do.

            I'm beginning to wonder if I didn't have a bad M3. One with a production flaw. I cannot believe people would keep on selling (and others buying) this PSU if all of them are pieces of crap like mine was.

            Anyway, now I'm happy with my M2 and I'm never buying an M3 again.
            BMW 525tds -Biostar I94GM-I4 -Celeron M44O 1,86GHz, M2-ATX, 1Gb, 320GB -HQCT RDS tuner -Creative Extigy -iBus controller -Lilliput 7" touchscreen -DLS Ultimate A7 amplifier -Focal 130K, 130V, 27V2 speakers

            Bezel Worklog-My Install -iDrive F01 RR Skin


            • #7
              I just recieved my M3 on friday, and have it all mocked up in my car. Currently, it survives cranks, even after long periods of ky on engine off, running the pc. Its currently running my pc (1ghz pIII, 2 system fans, 512 ram, onboard sound and video) as well as my usb gps reciever, non powered usb hub, griffin powermate, linksys usb g adapter, luetooth dongle, and touchscreen usb. It has no hiccups so far at all. The only thing that its not connected to is my usb dvd drive, but im not using it yet in my set-up. My only complaint comes not from the M3-atx, but the fact that my mother board doesnot support the power on and off from the atx connector. It has a seperate 9 pin connection with a momentary switch that must be used for power on and off. Ill post any problems i encounter from here on out.
              Car Pc progress meter:
              [-5%-------------------] Carpc build #2. So far, 20$ deep! I love recycling!

              "The car is the closest we will ever come to creating something that is truly alive" -Sir William Lyons
              My worklog


              • #8
                I have recently gone from the M1-ATX to the M3, and I noticed the same problems with turning on. I have to turn the key to IGN and wait until the PC starts, then start. The M1 didn't have this problem. I am considering switching to the M2-ATX, even though I really liked the size of the M3...


                • #9
                  You know, I instantly assumed the M3-ATX would be better than the M1-ATX, but now that I look at the specs, they really are very different... Here's what I have found from the datasheets:

                  Current (max)
                  5V 3.3V 5VSB -12V 12V
                  M1-ATX 10A 10A 1.5A 0.15A 2A
                  M2-ATX 8A 8A 1.5A 0.15A 4-9A
                  M3-ATX 6A 6A 1.5A 0.15A 4-6A
                  M4-ATX 15A 15A 1.5A 0.15A 8-12A

                  I really need to measure my current consumption on each rail to see how close I am to the limits. The hard drive will definitely need some extra at spin up so some extra overhead there would be good to have.