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Apache's in push/pull - Problem with using PWM?

Discussion in 'Overclocking & Cooling' started by AgedIdiot, 7 Oct 2009.

  1. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Running a Prolimatech Meg. cooler and have decided to go Push/Pull using 2 Apache's (ordered and due tommorrow:)).

    I could run them ,I think, by simply plugging them into a 3 pin Akasa fan cable splitter (already owned) and then running from my existing Akasa Pro fan control.

    OR

    I could use the Akasa PWM fan splitter cable (bought and awaiting delivery)and run them from the motherboard - An Asus P5Q-E.

    I am reasonably condfident that the first option will work and if I use this I can , of course, manually control the speed ,noise & temps.

    I've never used the PWM control on any board - I like the idea of it adjusting the speed when needed but from what I've read in my board manual the only control that the op. has is to choose between Standard/Silence/Turbo and I would have no control 'on the fly' ; true ?

    Anyone got an opinion which of the options is better than the other? and if so why?

    Also although I'm not too bothered if the fan controller got 'bust' using the first method ,I would not wish to damage my board if it could not/might not cope with running 2 fans via PWM. Is it likely to be a problem ?or am I simply being a little paranoid/(would not be the first time:o)
    Further possible 'dumb' question relates to the speed that fans run at i.e. if one runs two fans of one terminal (be it 3 pin splitter or 4 pin Pwm splitter) will they run slower or not be able to run as fast as one fan ?

    As anyone reading this will have surmised Science and more partic. electrics are not my strong suite (best ever Physics test result was , if memory serves correctly about 40% :confused:worst was ,I do remember, 13% :eek:after which it got dropped :D - this was in the 60's by the way)
     
  2. zsolmanz

    Associate

    Joined: 8 Aug 2009

    Posts: 54

    Option one will work. The fans will probably run slower (depending on if the splitter is series or parallel), but I'm not certain.
    With option two, either the fans will run slower or the board will have to provide more voltage (same reason as above). I'm not sure which, it'll probably be a bit of both.

    As for PWM fan splitters, never had any experience. I've always preferred the idea of speedfan controlling fans plugged straight in.

    What is the motherboard, how many 3- or 4-pin fan plugs does it have, and how many of them have the 4th pin? (Usually the CPU fan has one). (This is just to see if speedfan is a viable alternative).
     
  3. setter

    Caporegime

    Joined: 14 Dec 2005

    Posts: 28,160

    Location: armoy, n. ireland

    Ive run fans on both a controller and the akasa pwm cable on an asus p5q deluxe, in bios i had the fan profile set to turbo, in windows i controlled speed with asus ai suites fan expert i have three sharkoon pwm fans running on this cable, 2 on a TRUE and a rear exhaust, all 3 running in sync, my front 2 intakes are on an akasa junior fan controller, theese 2 though are standard 3 pin 2000 rpm sharkoons. Personally i prefer the pwm function as the motherboard does the work, as a failsafe once the cpu temp rises above 60c, the pwm fans will run full speed.
     
  4. Exsurgo

    Hitman

    Joined: 2 Oct 2009

    Posts: 819

    Location: Belfast, UK

    As long as the two fans combined dont draw more than 0.9 amps you should'nt be doing any damage to your board
     
  5. Arcane

    Mobster

    Joined: 19 Aug 2005

    Posts: 3,814

    Location: Ealing, London

    The Akasa fan splitter he's talking about also includes a molex connector so luckily you won't be powering them directly from the board, something I get a little nervous about. I'm looking for a couple of pwm fans myself for my new toys, are the apaches very good?

    [​IMG]
     
    Last edited: 7 Oct 2009
  6. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Thanx for the replies. Still undecided wether to risk PWM on board.

    Will decide over weekend.

    As mentioned in original post am useless at 'science' so if anyone could tell me if the two 12v fans would draw more than .9amps would be much appreciated (did try a google as to how to convert volts to amps but found the explanation VERY confusing in fact for me gobbledegook :o)
    Allegedly - yes :cool:
     
  7. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Came today and fitted.

    Tried the 3 pin via fan controller first - Abysmal :eek:basically not enough power was getting through to power the fans ; not even one on its own!

    Then tried with the PWM splitter , which has with it an extra molex connector (as you said Arcane)- bingo - running nice and quiet but cool.

    Will give it a few days but so far not overly impressed :( Had just tried push/pull with 2 Hiper blue led (nine blade) fans which were happily running from 3 pin and fan controller and cooling possibly a little better under load than the Apache's.

    The reason I am not sure if the Hipers are in fact a little better is the fact that they were not running under PWM , speed was constant (but quiet) and the max I got was 54c ; wheras the max I'm getting using the Apache's is 55c BUT the max fan speed it appears to get to is 1100 (rather than the 1300 they can actually get to.)
     
  8. setter

    Caporegime

    Joined: 14 Dec 2005

    Posts: 28,160

    Location: armoy, n. ireland

    Which fan profile have you got selected in bios? Im running 3 pwm fans on the splitter.

    [​IMG]

    2 on the cooler and the exhaust, you should be able to configure the fan speed in asus ai suite's fan expert, with the preset options the fan/s will only hit full speed once the cpu temp goes above 60c, my 3 pwm fans are rated to run at 400-1200 rpm, with turbo setting theyre currently sitting at 948 rpm.
     
  9. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Fan Profile - Standard

    Running the 2 fans alone - the rear exhaust fan is a 140mm coolermaster (haf case) so I've left it alone.

    I have assumed that as both fans are being run via the PWM splitter they are both running at the same speed as controlled by the motherboard. Speedfan only sees the one fan which at moment is running at 709 rpm (If I'm wrong in my assumption please advise - it looks o'k but ????)
     
  10. setter

    Caporegime

    Joined: 14 Dec 2005

    Posts: 28,160

    Location: armoy, n. ireland

    Yep, it will only show as one fan, i dont use speedfan myself, but asus ai suite lists the rpm for the cpu fan. As im running 3 fans via pwm, this speed is actualy the speed of all three fans.
     
  11. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Thanks - good to be reassured
     
  12. Clairvoyant

    Soldato

    Joined: 19 Oct 2002

    Posts: 6,140

    Location: Torbay, Devon, UK

    Sorry to hi jack this thread.

    But does anyone else get as strange noise from their Apache`s via PWM. Its like a hi pitch hummmm then goes for about a second then goes away then back.

    like up and down up and down (the RPM goes up and down all the time eg 502 to 527 back to 502 etc etc)

    If ya know what I mean.

    Its getting annoying.
     
    Last edited: 8 Oct 2009
  13. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Not here - Yet :eek::eek:

    And am on same motherboard
     
  14. Clairvoyant

    Soldato

    Joined: 19 Oct 2002

    Posts: 6,140

    Location: Torbay, Devon, UK

    hmm

    My RPM is going up and down but i dont think its the fan thats making the noise.

    I stopped the fan and it still makes the noise not as loud. And if I have the fan running at full speed. It goes up and down still 1318 RPM to 1507.

    Im going to unplug it now see if that cures it.
     
  15. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Just had a 'play' with speedfan and noticed that the fan sped does vary often - on mine between 686 & 720 rpm wether running anything or not and it does not appear to go any faster even when running 25% load.

    No hum tho
     
  16. Clairvoyant

    Soldato

    Joined: 19 Oct 2002

    Posts: 6,140

    Location: Torbay, Devon, UK

    Ok after unplugging all my fans. And going one by one. Its on of my intake Scythe S-FLEX 1600RPM Ultra Quiet 120mm Fan.

    But now this is the strange part. If I take the front cover off (antec 300) the noise goes away.

    Im wondering if its vibrating on the front of the case.
     
  17. Arcane

    Mobster

    Joined: 19 Aug 2005

    Posts: 3,814

    Location: Ealing, London

    AgedIdiot,

    Would you say overall that you're pleased with the results using the Akasa splitter? I doubt I'll use speedfan, i'd like to "set and forget" via the bios, do you think it'd be ok?
     
  18. thebandit

    Hitman

    Joined: 5 Mar 2009

    Posts: 748

    Location: Essex

    I really like reading these forums, its amazing what stuff you pick up, I had never seen these Molex PWM fan controller splitters but it's a good idea and just what I need, sold.
     
  19. setter

    Caporegime

    Joined: 14 Dec 2005

    Posts: 28,160

    Location: armoy, n. ireland

    I can say that im well pleased with it, i ran it on my previous p5q and q9550 combo at 3.8ghz, temps never went higher than 55c, decided to stick with it on my i7 rig.
     
  20. AgedIdiot

    Wise Guy

    Joined: 31 Oct 2007

    Posts: 2,343

    Location: Gods County(Allegedly)

    Yes - Although initially I was a bit concerned wether using PWM was a good idea ,I'm being converted as I get used to the way it works:).

    I have been seduced by the quiet operation and the knowledge that if I load the comp. then as and when required the fans will be speeded up.
    Also it is nice to know that if the cpu fan fails my Bios will tell me etc.

    The hard bit is getting used to the idea that you are no longer looking for the coolest temps. either at idle or under load - obviously the fans are only spun faster if needed and as , from what I've read , it will only push the fans to full speed if my cpu's temp gets above 60c, I'm never (not with this chip Q9650 @4ghz and max temp of 55c under IBT) going to see what it could cool to. :D
    May ,one day, try running the fans independently of PWM at full chat to see what they could cool to but having been converted to PWM (if your looking to run more than one fan then the Akasa splitter with its extra molex connection is, I believe, the essential extra) I do not see myself going back to old 'standard' connections.

    It's only been a couple of days but I'm just about converted (to be sure I need to run it for a few months ) and if I were looking to change system in the future I would look , as Setter did, to continue to use it.(watercooling apart) :D:D BTW I do not run speedfan or other testing programs all the time -they are just a useful tool to be used from time to time to see what is going on ; as required.