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

[AgedIdiot]

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)
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% worst was ,I do remember, 13% after which it got dropped - this was in the 60's by the way)

 

[AgedIdiot]

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 )

are the apaches very good?

Allegedly - yes

 

[AgedIdiot]

Came today and fitted.

Tried the 3 pin via fan controller first - Abysmal 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.)

 

[AgedIdiot]

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 ????)

 

[AgedIdiot]

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.

Thanks - good to be reassured

 

[AgedIdiot]

Not here - Yet

And am on same motherboard

 

[AgedIdiot]

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

 

[AgedIdiot]

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?

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.
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) 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.

 

[AgedIdiot]

Would all the fans have to be pwm? I've been told that I would only need one of the fans on the splitter to be pwm and that the splitter would ensure that all the fans would regulate with it as long as they were 3 wire? I'm not sure if that's the case, what do you guys think? I'm kind of leaning towards two gentle typhoons on the cooler and a pwm fan as an exhaust if it is correct.

As I have very little technical ability - as mentioned in first post - I am probably not the best person to answer the question but here goes :

I believe that 3 pin fans will work with a four pin PWM splitter BUT I have my doubts wether all fans will be running at same speed and controlled via PWM from the motherboard.

If I'm wrong then would someone please correct me

I understand that the typhoons are good fans (custom pc did recomend them in their recent fan review) but I do not think they are as good as the Apache's. For approx £12 more you could get 3 Apache and run 'em all PWM of the splitter- job done