120mm Fan with 4pin PWM connector?

signal64 · Post by **signal64** » Sun Apr 09, 2006 11:31 am

I have a situation that requires using 120mm fan that is 4-wire PWM Controlled and can plug into a 4pin fan port on the motherboard. It's for a CPU Heatsink.

That combination seems to be a bit rare.

So far I've found two JMC fans that look like overkill (being high CFM and noise) and possibly a Silverstone one.

The 120mm fan favorites that folks here seem to like do not appear to have the built in pwm option.

Any ideas?

Many Thanks.

frankgehry · Post by **frankgehry** » Sun Apr 09, 2006 4:01 pm

The 4-wire pwm fans that I'm aware of are high speed models. Since they are controlled by pwm they will run at slower speeds than a low speed 3-wire fan. There's no point in having low, medium, and high speed models.

signal64 · Post by **signal64** » Tue Apr 11, 2006 10:35 pm

True, but as my motherboard puts out 100% duty cycle on power up before switching over to cmos settings, it was something to consider.

I must have been reading the JMC-1238 specs and not the JMC-1225.
The 1238 puts out 150CFM@4000RPM 13v which had me a little freaked.
Didn't want it to rip off on startup.

The 1225-12H seems more reasonable at a max of 2600 RPM which is adjustable as you mentioned.

Question is now where to find one.

Only sources I've found so far are frozencpu and performance-pcs.
Both are out of stock and no dates on when they will be back.

Any other sources someone can recommend?

Thanks

frankgehry · Post by **frankgehry** » Tue Apr 11, 2006 11:17 pm

Skyline is a jmc distributor and is listed at www.jmcproducts.com. They also have everflows (silverstones), but I would prefer a jmc. I've purchased both regular and pwm fans from skyline. I would explain the problem to them and see what they suggest. A pwm fan has a ground, 12v, tach, and pwm wire. I've tested mine with 5v and they still work fine, so you could install a resistor in the 12v line to reduce the top speed. You could probably wire in a fan mate that would allow you vary the voltage and find the best operating range. But before going to all this trouble, you may want to check with abit. I know that in my bios there is a setting for pwm or dc.

signal64 · Post by **signal64** » Sun Apr 16, 2006 3:32 am

Performance-pcs got them back in stock.

In BIOS the only thing I could find was to disable speed control for CPU fan, but that didn't solve it.

Just odd that some PSU's worked and others not (all rated 550w plus) with a 3pin fan. Pluggin in a PWM 4pin worked on all.

About ready to give up on this board as there are some other BIOS issues that I've been able to confirm with other users. Doesn't help with Abit being unresponsive to any support requests as well.

I'm ordering the JMC anyway as it'll come in handy later on as well.

Thanks all.

bobov · Post by **bobov** » Wed Apr 19, 2006 7:13 am

http://www.performance-pcs.com/catalog/ ... ts_id=3977

signal64 · Post by **signal64** » Wed Apr 19, 2006 11:11 pm

Yup, I think I covered performance-pcs (including that they were back in stock

).

But thanks for pointing out the link for those needing one.
Performance-PCS isn't a bad place to shop from.

Thanks

TomZ · Post by **TomZ** » Fri Apr 21, 2006 1:34 pm

I've got a couple of JMC's here I bought from Skyline. They're pretty quiet at low speeds, and move a good amount of air and make some noise at higher speeds. Typical tradeoff like other fans, e.g., Antec TriCool.