Advantages to three-pin vs four-pin fans

[Assoul]

I'm really wondering what the advantage is to using three-pin vs. four-pin fans. I've had nothing but problems with the three-pin case fans that came with my NZXT H630 and am ready to replace all of them with four-pin counterparts. Namely that, it seems, four-pinners will adjust their speed more accordingly to system / CPU temperature while three-pin fans don't have this service as well developed. Either way, all the fan headers on my mobo are four pin, so I would expect all good case fans to take advantage of it.

As an example, I purchased (and had to return) a Noctua D14 since it came with two three-pin fans split into a Y cable that attached to the CPU FAN motherboard header. After reading that the Y will cause the fans to constantly spin at the same speeds, I'm wondering why Noctua wouldn't include two four-pin fans to take advantage of PWM.

I'm looking to us a Silverstone CPF04 to control all my fans. Doesn't it make sense that fan speed be dictated by system load? I even considered purchasing an automatic Thermaltake fan controller, but, low and behold: all the connectors on it are three-pin and it doesn't connect to the SYSFAN header, but rather attaches to your CPU heatsink via a metallic clip. It seems too unreliable this way.

I might be missing something here, but why would any vendor make three-pin a choice over four?

 

[mikeymikec]

I might be missing something here, but why would any vendor make three-pin a choice over four?

Backwards compatibility?

 

[Deders]

Yeah that's a strange decision to not have PWM fans for a CPU cooler. Someone else mentioned this in another forum. The NH-D15 comes with PWM.

You should still have the option in the bios somewhere to adjust your fanspeed automatically depending on the temp.

 

[dlerious]

I might be missing something here, but why would any vendor make three-pin a choice over four?

3-pin fans are DC controlled. Not all 4-pin headers are PWM capable. I use 4-pin PWM with an Aquero.

 

[Assoul]

Backwards compatibility?

How far backwards do you need to go? The motherboard I purchased has four pins on all fan headers, and the NZXT H630 it's installed in uses only three-pin fans and even has a three-pin-only fan hub. Makes no sense.

Yeah that's a strange decision to not have PWM fans for a CPU cooler. Someone else mentioned this in another forum. The NH-D15 comes with PWM. You should still have the option in the bios somewhere to adjust your fanspeed automatically depending on the temp.

I actually wrote to Noctua requesting that they exchange the DC fans that came with the D14 with PWM fans. They replied with some BS excuse. Here's a link to my resulting Amazon review: (http://www.amazon.com/gp/customer-r...iewpnt?ie=UTF8&ASIN=B002VKVZ1A#R1IPJJ6T6HB4S3). Returned it and never going with another Noctua product again.

And yes, I was able to adjust it to voltage, but the results weren't as good as using true PWM fans, which is what I have now.

3-pin fans are DC controlled. Not all 4-pin headers are PWM capable. I use 4-pin PWM with an Aquero.

I'm using the CPU_FAN and SYS_FAN on my Gigabyte motherboard and they both work very well. 800-900 RPM during idle and 1200 - 1500 RPM during load. The point is that vendors really should be getting with the program and provide something that uses today's technology as a regular standard.

 

[mikeymikec]

How far backwards do you need to go? The motherboard I purchased has four pins on all fan headers, and the NZXT H630 it's installed in uses only three-pin fans and even has a three-pin-only fan hub. Makes no sense.

However the Noctua D14 can be installed on AM2 boards, so that's going back to 2006 I think? At a guess I'd say I first started seeing 4-pin headers in 2011 maybe.

 

[Assoul]

However the Noctua D14 can be installed on AM2 boards, so that's going back to 2006 I think? At a guess I'd say I first started seeing 4-pin headers in 2011 maybe.

The Noctua customer service rep was BSing me. I don't appreciate him saying anything other than "you're right - we should have been supplying the NH-D14 with PWM fans since 2005 since it wouldn't hurt if you used it on a voltage-only header and you certainly paid top dollar for it." Again, I don't know who he's trying to fool but I don't appreciate being patronized.

Besides, my previous Gigabyte GA-P5-32DSL had 4-pin support and I purchased it in 2008.

*Edit: It was a GA-P35-DS3L (http://www.gigabyte.com/products/product-page.aspx?pid=2629#ov)

 

[mikeymikec]

The last two AMD boards I used (2010, 2009, both AM3) had a single 4-pin CPU header, but the rest were 3-pin.

Another scenario is low-end boards vs. mid/high end boards: I only buy mid/high end boards, but I've seen some crazy limitations on low-end boards (like AM2 era boards that don't support dual-channel).

 

[aigomorla]

I might be missing something here, but why would any vendor make three-pin a choice over four?

u can use a 4 pin header on a 4 pin or 3 pin fan as its backwards friendly.

however u can not use a 3 pin header on a 4 pin fan.

Some itx boards, or older budget boards only have 3 pin headers outside the cpu, so noctuna wanted to make sure incase u decided to use the fan elsewhere, you would not run into compatibility issues.

There is no advantage i see on using 4 pin over 3 pin.
Infact the only pwm fan i used to trust several years ago was the only the intel stock fan, as all other pwm fans just flat out sucked.

Also when using fans for your radiator, its hard/expensive to find a good working PWM splitter to use 3 fans on your 120x3 radiator.
A member mentions aquero, he also forgets to mention that is a 200 dollar fan controller

 

[dlerious]

I also have a few Swiftech 8-way PWM splitters along with that Aquero. It was the $200 one (6 XT). It does a lot more than just fans though I have EK 3-way splitters for my Vardars. Darkside has some 3-pin splitters that have staggered lengths - like to find 4-pin like that. see http://www.performance-pcs.com/dark...x-fan-y-splitter-cable-jet-black-sleeved.html

 

[JeffMD]

3 pin fans were speed controlled via changing the voltage, where as the voltage on 4 pin fans is the same, the rotations are simply sent through a second wire. The former is a very inaccurate and unsafe method and you will find that most motherboards today have done away with voltage changing on 3 pin fans. This was the case in my MSI core2 motherboard. If you want to modify fan speeds, go with a 4 pin.

 

[UsandThem]

Most of the 4 pin fan headers on Gigabyte motherboards aren't actually PWM. On most of their boards only the CPU and OPT headers are truly PWM. They don't broadcast this, however it is in their manual.

I read the review you linked to, and I don't understand the hate for Noctua. They provide extremely detailed information and specs for their products, and make different products for different needs.

I could see if the specs said it came with PWM fans, however they instead gave you 3-pin. The key is to know what fits your needs and to order the correct product.

 

[Magic Carpet]

As an example, I purchased (and had to return) a Noctua D14 since it came with two three-pin fans split into a Y cable that attached to the CPU FAN motherboard header. After reading that the Y will cause the fans to constantly spin at the same speeds, I'm wondering why Noctua wouldn't include two four-pin fans to take advantage of PWM.

Originally, Noctua started out with DC controlled fans only. D14 is a very old model and that's why it didn't include PWM fans. They began to include PWM fans in later revisions. You could, however, swap the included fan with another one, though.

Personally, I prefer DC controlled fans, mainly because I like manual control (with the use of adapters and/or fan controllers). But I understand the people not wanting to mess with these things and just let the bios/app do it for them.

Depending on application, use and parameters either implementation works fine. Just, if you decide to get a PWM fan, make sure it's a quality one. The cheaper ones are very annoying at their maximum rpm, usually it takes a few to several seconds before the bios control kicks in to spin it down (happens on every boot/resume from sleep).

 

[BonzaiDuck]

Someone mentioned the Swiftech 8-way PWM splitter, and those things are worth every penny of the ~$10 price-tag on each.

Power on the Swiftech comes from the PSU -- not from the motherboard. A single connection to either a CPU 4-pin fan header or a 4-pin "case fan" header will then supply the single signal to control up to eight PWM fans.

One might say "Well, sure -- but I want to control several fans differently." But if you design your case-cooling strategy to keep it relatively simple, you can have two groups of fans -- say, intake and exhaust -- controlled from two different motherboard headers.

I think the Silverstone item mentioned by the OP is a similar device.

Certainly, the Aquaero controllers are excellent. But you can do a lot with PWM fans and a motherboard with an adequate number of PWM 4-pin headers using these simpler devices -- Swiftech, Silverstone -- I think Akasa makes one also.