CPU fan slow to spin up

[Randybob01]

Putting together my new system:

Intel i7 3770, stock cooler
Gigabyte GA-Z77X-UD5H mobo
Antec Earthwatts 650W PSU (old, but I'm not going to use a high-powered graphics card for now)
G.Skill F3-12800CL9D-8GBXL RAM kit, only 1 4 GB stick in the system now

Anyway, the CPU fan tries to spin up a few times when I turn it on, but doesn't really get going until about 20-30 seconds after I turn it on. My case fans of course spin right up. I have detached both the case fans from the motherboard, and hooked them up directly to the PSU via Molex-to-3-pin adapters. Is this spin-up time/behavior normal for an i7, or am I right in suspecting something is wrong here?

 

[philipma1957]

Putting together my new system:

Intel i7 3770, stock cooler
Gigabyte GA-Z77X-UD5H mobo
Antec Earthwatts 650W PSU (old, but I'm not going to use a high-powered graphics card for now)
G.Skill F3-12800CL9D-8GBXL RAM kit, only 1 4 GB stick in the system now

Anyway, the CPU fan tries to spin up a few times when I turn it on, but doesn't really get going until about 20-30 seconds after I turn it on. My case fans of course spin right up. I have detached both the case fans from the motherboard, and hooked them up directly to the PSU via Molex-to-3-pin adapters. Is this spin-up time/behavior normal for an i7, or am I right in suspecting something is wrong here?

sounds wrong to me

 

[Randybob01]

Is this the sign of a bad mobo? Would that be long enough to brick the CPU?

 

[philipma1957]

I built 8 machines this year. most with custom coolers one with a stock cooler. in all cases the fan spins up fast. Intel coolers are considered low cost junk. My guess is the fan in it is bad. I would think to get a cooler from newegg

if this fits it is decent and a small price to pay to protect a 300 dollar cpu

http://www.newegg.com/Product/Produc...82E16835103099



if coin is tight

http://www.newegg.com/Product/Produc...82E16835226050

this one is smaller and will fit in more cases.

 

[ShintaiDK]

CPU cant get damaged due to heat. It would throttle before and even shut off if needed.

Also I dont think its an issue if the temp havent build up. You might simply have a quiet fan setting in your BIOS.

 

[philipma1957]

the gigabyte boards do have a quiet fan setting.

what I found interesting is the fan spins then stops then starts.

My h77 matx gigabyte board with a low fan setting and the 92mm silenx fan/cooler I listed just spins. you are correct that it should not kill off the cpu as a passive heatsink alone should allow the cpu to throttle down safely.

 

[JimmiG]

Automatic fan control causing the fan to not spin up until the CPU has reached a certain temp?

 

[sm625]

This is normal behavior. I have seen several gigabyte motherboards with cpu fans that start then stop and kind of bump bump bump a little and then finally start. I'm sure it is because the temperature is so low at first that it just leaves the fan at such a low rpm setting that it is not actually enough power to start the fan. (A fan requires only a small amount of power to run at a low speed, but it requires significantly more power to start itself and reach even a low speed.)

It wont hurt anything because eventually the chip warms up enough to where enough voltage is fed to the fan that it will get over the startup hurdle.

Technically it is a bug because whoever wrote the algorithm to change the fan speed based on temperature should have taken into account that current draw is very nonlinear at 0 rpm.

 

[VirtualLarry]

Disable "quiet fan".

 

[mtnd3vil]

My Gigabyte LGA775 motherboard would do this too and I was using the fan at full power in the bios. It started to spin for a split second at power up, then stopped, then 10 seconds later spun at full speed then on. I assumed it was a Gigabyte thing because I've never had one before or after.