Why Nexus fan RPM is higher then Intel Boxed one?

archiver · Post by **archiver** » Wed Dec 26, 2007 10:23 am

Hi,

Why Intel motherboard with 4 pin CPU fan control with E6550 boxed fan is 850 RPM and when replaced with Nexus (PHT-7750) with copper heatsink silent fan RPM is 1150?

Temperature is alwys constan't at 29-32 Celsius.
Motheboard is Intel DQ35JO.

tehfire · Post by **tehfire** » Wed Dec 26, 2007 3:07 pm

The stock Intel HSF has a PWM-controlled fan, meaning that it changes speed depending on how the CPU is at the time. I think that 850rpm mark is it's slowest or near its slowest speed.

Perhaps that Nexus always runs at full speed? Is the Nexus you installed a 4-pin or a 3-pin fan? If it's a 4-pin fan, it is very possible that you could slow the RPMs down with a software program (Like Speedfan or similar).

archiver · Post by **archiver** » Wed Dec 26, 2007 11:54 pm

Nexus is a 4 pin PWM.

http://www.nexustechnologyusa.com/c/ntu ... 750_1.html

Speedfan has failed on DQ35JO motherboard. The temperature was wrong approximately +40% and I can't imagine any easy way to calibrate it.
Intel Desktop Utilities had to be uninstalled but still
Speedfan either couldn't display fan RPM at all.

Looks like Nexus PWM response compared to Intel fan is different and Intel PWM output doesn't provide sufficient controll according to CPU and chipset temperatures.

As my C2D (E6550) CPU is seriously overcooled - is there any other suitable external control methods to lower RPM? Purpose is to reduce Nexus noise and RPM at least to the same level as of boxed cooler.

The CPU boxed fan RPM increases aproximately 5% under heavy CPU burden, so it may be that motherboard control is present but now overcooling CPU and out of range for this CPU. While cooler has to provide also airflow for rest of chipsets, I believe that lowering RPM to boxed fan level is totally safe.

L34K_B4RAK · Post by **L34K_B4RAK** » Sun Dec 30, 2007 5:04 am

Perhaps Nexus drawn more current/ampere than Intel.

jcuesico · Post by **jcuesico** » Tue Apr 22, 2008 3:07 pm

I've used a zalman fanmate2 with a pwm fan. The fanmate will shift the operating range of the fan. I've used this thread as a reference.

Go look at the picture a few posts down the thread.

ultraboy · Post by **ultraboy** » Tue Apr 22, 2008 5:19 pm

archiver wrote:Speedfan has failed on DQ35JO motherboard. The temperature was wrong approximately +40% and I can't imagine any easy way to calibrate it.
Intel Desktop Utilities had to be uninstalled but still
Speedfan either couldn't display fan RPM at all.

Do you mean Speedfan doesn't control any fan at all, or it just reports wrong temp?

If the latter, you can try Speedfan beta since the non-beta has some issue with C2D reporting.

Edit: Just notice that a new Speedfan 4.34 is launched today - so give it a try whether it now work for you.

archiver · Post by **archiver** » Wed Apr 23, 2008 1:58 pm

I'll give a try to new speedfan.
In meantime I replaced the fan to the newer one and now RPM is approx 600.

Can't recall Speedfan -
But Intel utility monitors also chipset temperature, which without any active cooling tends to be very high. Therefore CPU cooler design provides some neccessary airflow also to the closest neighborhood including chipset.

Obviously testing with a closed cabinet can only provide any final measuring results.

btw- I abandoned Intel 35JO because 2 tested units had rather audible noise from audio line out ... veeery far from promised noise levels - these 2 units were a most obvious crap if considering audio quality - I just started tuning from the wrong end