Is it normal for CPU fan to drastically change speeds?

Yes it's normal as your CPU gets hot while gaming. Your cpu fan and video card fan will switch to higher RPM under load.

yes it is normal as long as your fan speed is set to Auto. as mrblazito said, it will change the speed within the cpu's current temp...

what temps are you getting???

the temps are still normal. 30C idle and up to 59C under load.
the Cpu is overclocked.

i was just concerned weather the Fan might break if the rpm gets too high. and im curious about this because before yesterday the fan never went above 4000rpm.

those are absurdly high speeds. I've never seen any fans that go that fast.

Fastest these fans usually go is about 3000 RPM, but 2000 is typical.

generally a fan when quiet operates around 1000 RPM.

You might seriously want to check your readings.

what kind of fan you have???

Probably a delta engine or something... I know no ordinary PC fan that goes up to those speeds.

I know AMD's stock heatsink/fan that has the copper heat pipes, it's fan can exceed 5,000rpm, it's the reason so many people complain it's noisy.

exceed 5000 RPM???????  

Im going to see if the boxed cooler that came with my Phenom 2 does that!

Yup

wow, that would probably compete with a basic water cooling system..lol

Yep there are some that get as high as 7200RPMs for example this one -- ( LINKIE ) or this 8000 RPM one by Evercool ( LInkie )

so for some reason the fan goes back to normal. then on certain days it will shoot up again during CPU intensive things. and yes its stock Amd with the copper pipes. i think it may have something to do with the Room temperature. because i never have the problem when the AC is on.

its wierd though because i almost wish it would stay that high. with that kind of speed i could probably manage a bit more OC

You could adjust the profile to make it run at 100% speed at a lower temp if you wanted.

what do you mean by profile? and what program would you use to do that? or would you use the Bios?


also you dont think running at speeds that high could damage the Fan over time?

indeed, you may something confused a jet play flying around your town with that fan when its all quite.

That always been up for debate on here so i doubt you'll get a straight answer.

For me, i would say: If it a bad quality fan, yes. It would have quickly in a short period of time. If it decent to high quality fan (most stock HS Fans are high quality. (im not talking about cooling performance, just the fan quality itself)) Then i doubt you'll notice the fan performance drop before you buy a new cpu.

Lets just say that my fan on a Intel P4 prescott (nicknamed presshot), can flex between 2800RMP to over 4200 RPM's and that been doing it for 5 years without a single rpm drop.

So i doubt that you'll notice the difference in the fan now @100% between now and a few years from now when a cpu change is in order.

Fixed  

Mines a different fan from the 478 socket. i should of been clearer on that.

To be honest, if you are planning on doing OC, you should get an aftermarket cooler/fan. In fact, you should just get an aftermarket cooler fan anyway, unless you want your room to sound like an airport.