Newbie questions on heatsink fans

[wgoldfarb]

A few months ago, after a LOT of reading on this site and *great* help from many people here, I finally built my first rig. Now I decided to take the next step and try my hand at overclocking. To that end I am replacing the Intel stock HSF I've used up to this point with a Thermalright Ultima 90. My questions relate to the fan that will go on the Ultima 90.

I am running a Core2Duo E6600 in an Asus P5B Deluxe, housed inside an Antec P180b. I am not going for any extreme overclocks -- if I get to 20% I will be very happy. My aim is to overclock the system, but keeping it as silent as possible. Thus I will probably choose a 120mm fan. I know that in their review, AT paired the Ultima 90 with a Scythe 120mm SFF21F fan that runs at 1600 RPM.

Since I am not going to do any extreme overclocks I am thinking I can get by with a lower fan speed than 1600RPM and have a more a silent system while still maintaining adequate temperatures. My idea is is to get a Scythe SFF21F 1600 RPM but with some type of speed control (such as a Zalman Fan mate 2) so I can lower the fan speed as low as possible while still maintaining adequate cooling.

This all sounds very good to me, but I am wondering if this is a bad idea for any reason. Will I be able to get adequate cooling at lower speeds, or is using anything less than the 1600 RPM fan a bad idea? How about using the Fan Mate 2 controller on the HSF fan? Or shoudl I just get a lower RPM fan without a controller?

The second part of the question is where to connect the fan. I know I can connect the fan's 3 pin connector to the MoBo's CPU fan 4 pin header by just leaving the PWM pin unused. Is there any advantage or disadvantage of using the CPU fan header on the MoBo versus using one of the 3 pin case fan headers? Will using a speed control such as the Fan Mate 2 make any difference in terms of where I should connect the fan?

Thanks in advance for any help!

 

[VinDSL]

Sounds like you got it aced!

And, personally, I'd use the case fan header. Why? I dunno, that's just what I like to do...

 

[Billb2]

Fan performance is usually denoted by the CFM (Cubic Feet per Minute) rating of the fan, not RPM as RPM tells you nothing about the fans performance.

If you use an external speed controller it should be powered directly by the PSU (off of a 12v molex connector).

Overclocks are limited by heat as eventually you'll start increacing voltages. So, in your statement "My aim is to overclock the system, but keeping it as silent as possible" as silent as possible depends on how much you overclock and you wont know that until you actually do it. So choosing the optimal fan is a shot in the dark now.

A reasonable starting point would be a 100 CFM fan on a rheostst (5 ohms, 5 watts. available at any electronics parts store).


Scythe SFF21F Specifications:

* Dimensions: 120 x 120 x 25mm
* Fan Speed: 1600RPM
* Fan Noise: 28.0dBA
* Air Flow: 63.7CFM
* Current: 0.20A
* MTBF: 150,000 Hoursarting place would be a 100 CFM fan on a rheostat.

 

[VinDSL]

Fair enough...

Okay, go with ONE OF THESE

Latest and greatest!

 

[wgoldfarb]

VinDSL, Billb2,

Thanks for the answers, quite helpful. I will take a look at some higher CFM fans, including the Scythe VinDSL mentioned, and couple them with a rheostat, as suggested by Billb2.

 

[HeatMiser]

If you haven't already, you also might just try getting the lower CFM Scythe with the heatsink and see how loud it is -- just plug it into a fan header on your mobo. With that heatsink, a good fan (even lower CFM), and your modest goal of a 20% overclock, I doubt you will have any temperature problems. Loudness can be pretty subjective (and dependent on ambient noise) and you might find that a simple set up is all you need to get the right loudness/cooling you are looking for. Try that, then if you don't like the noise, the other guys above have some great suggestions.

 

[wgoldfarb]

HeatMiser,

Thanks for the suggestion. I have an Antec Tricool, so I will try the Ultima 90 with the Tricool at the three speeds (approx 73 CFM, 53 CFM and 30 CFM). This will give me a better idea of how much air flow I really need on the Ultima 90 to cool my CPU at stock speeds. Once I know that I can decide what fan to get, keeping in mind that I might need some added airflow once I start overclocking.

Thanks again to everyone for your answers! :thumbsup:

 

[WoodButcher]

That Asus you have can set the fan speed in the bios if you use the cpu mobo header. IIRC you can set it to operate at temperature or voltage. Sorry, I haven't run an air cooled system in a while so I don't remember.