Is your P3 slot 1, socket 370, or "slocket" based? Also, what speed is your P3 CPU?

My P3 is slot-1 and is a 650mhz coppermine (running on slot-1 Intel SE440BX-2 mobo)

I have never heard about a 440BX mainboard with dynamic CPU fan speed... To get these 5x5cm Pentium 3 fans running silently and sufficiently for a long time; set them to 8,5 Volt instead of the default 12 Volt. But you need some small fan voltage control unit, which you can buy or assemble yourself from a few electronic components. I have one fan control thingy from zalman, and made two adjustable ones myself. I can not live without them 😉.

I use a Noctua 120mm case fan on a P3 800mhz coppermine. It doesn't fit correctly, but it hangs on OK if you use an elastic band. 😉 The fan goes round at only 800 rpms, and is virtually silent, but it keeps the CPU cool in the low 30s.

I suggest you experiment a bit. Unscrew the noisy CPU fan, and see if you can mess about with larger (quieter) fans, by propping them up against the hole where the fan once was. Then run any software that tells you the temperature of the CPU, to make sure it's not getting too hot. You could try speedfan or everest home, as 2 free examples.

Also, consider getting a passive P3 CPU. ebay's a good bet. I think I've seen them as fast as 733mhz for passive CPUs. The best solution is to tie on a fan to these passive CPUs, as some of them can still get very toasty.

Ok i think i will experiment with different fan types 😀 But i am sure my CPU fan was not this fast or loud when it was assembled in my old case.... but my old case might have been better at hiding the noise? The back of the new case has many holes/grills so that is probably why i am hearing it more!

I have been reading the SE440BX-2 manual and it says that the smart fan control is included with motherboards that have voltage/fan speed sensors... mine does have these sensors! there is nothing else in the manual regarding the fans except the location of the fan headers but thats it.

Anyway thanks for the advice 😒

Oops my mistake... the smart fan control mentioned above is actually done via software and not the motherboard itself! I had a look at the official Intel SE440BX-2 manual and it does not mention anything about fan speed control.... it just mentions the speed sensors.

The other manual i was looking at was for Compuadd PC's that came with the Intel SE440BX-2 motherboard... slightly different to the Intel manual 😖

So my conclusion is the motherboard can read the fan speed via sensors but cannot adjust the speed? oh well i guess i will get a cheap fan control bracket off ebay 😁 and bring the fan down from 6000 rpm to around 3500~4000 rpm 😀

retro games 100 wrote:

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Also, consider getting a passive P3 CPU. ebay's a good bet. I think I've seen them as fast as 733mhz for passive CPUs. The best solution is to tie on a fan to these passive CPUs, as some of them can still get very toasty.

I've got my first 440BX in many years running again (old MB, new to me from the 'Bay), currently with a P2 at 350 MHz, and the only heat sink that fits is a passive type, but that won't be good enough off the breadboard table, where it can dissipate heat very readily. Those Slot1 CPUs came in at least three distinctly different packages, for which that many different pattern coolers have to be found.

I have a 233 MHz one with one style spring clip (dead CPU), a 266 MHz one with a dead fan on its cooler (and no easy way to adapt a more ordinary small fan to it), the 350 one, and a couple of heat sinks for a widely spaced spring clip version of the four-screw hex-head type, for which I have no matching CPUs. The fins on the particular passive style cooler I have now aren't compatible with any of the several small fan sizes I've tried.

Kiwi wrote:

I've got my first 440BX in many years running again (old MB, new to me from the 'Bay), currently with a P2 at 350 MHz, and the only heat sink that fits is a passive type, but that won't be good enough off the breadboard table, where it can dissipate heat very readily. Those Slot1 CPUs came in at least three distinctly different packages, for which that many different pattern coolers have to be found.

I have a 233 MHz one with one style spring clip (dead CPU), a 266 MHz one with a dead fan on its cooler (and no easy way to adapt a more ordinary small fan to it), the 350 one, and a couple of heat sinks for a widely spaced spring clip version of the four-screw hex-head type, for which I have no matching CPUs. The fins on the particular passive style cooler I have now aren't compatible with any of the several small fan sizes I've tried.

My old PII 233 had one of the original slot-1 intel heatsinks with the fan built into it (not sure if the fan could ever be changed??) My PIII 650 has a long aluminium heatsink with fins and a standard 60mm fan screwed to it. The only problem i had was with the CPU retention brackets... they would lock a PII firmly in place but not a PIII (both CPU's have slighty different casings).

The 266 CPU came with an unusual fan that clipped onto the heat sink around the top and bottom sides. The fan housing and a shroud to enclose much of the top and bottom sides were integral, all one piece. The power cable to/from the fan on mine is missing, and it's not something that can be fabricated in a home shop (that cable).