Thermalright Ultra-90 Fan Problems

[UseItNow]

I need help folks, in a bit of bother, having installed everything in a new system, now having difficulties with the CPU cooler fan.

System:
Intel E6750
Gigabyte P35C-DS3R
Ballistix PC2-5300 2Gb
Thermalright CPU Cooler Ultra-90 with Zalman ZM-F2 Fan (3 Pin)
Corsair HX520W

It seems that the cpu cooler fan does not always start up with the start power up. When first having started the system it was fine, but after a long while shut off, restarted and soon noticed that the fan was not spinning, turned it off immediately. After a couple attempts to see if it was a one-off, restarted a third time, it spun up, has since.

I've checked the connections, everything is fine, I am just wondering if there is something I might have missed in the BIOS.

I only used this fan as it was used in the frostytech tests and gave good results, no pointing fingers there! Now the system starts up, but upon going into the bios, the system reads CPU temperature as 26 degrees celsius and system temp as 37 degrees celsius, with the fan running at only 1250rpm or so. Upon initial boot, the fan ran at 2540rpm or so as the max speed. This is fine, its rated speed is 2600rpm (max). As I didn't use the extra cable, the fan should be running at around that of 2600rpm, it's not, ever since the second cold boot, its been running at around 1250rpm, thats well below the 1600rpm (min) speed when used with the extra cable.

I will stress that the fan is a '3 PIN', hence not a PWM? as is the stock HS. Hence, no spped control.
I'm baffled, could do with pointers.

It seems now that everytime I start the PC from a shutdown, the fan spins up about a second or so from the power-up.

I would still like opinions and checks, guide to what to do next, tests?

I might just change it with another fan, if so, what would be recommended?
There must be some recommendations with the number of people with Thermalright coolers, remember it has to be a 92x92x25mm fan.

Thanks again, all help appreciated!

[UseItNow]

Please, anybody?

Note: Noticed that the fan takes a few seconds to start up.

Thanks.

[Clunk]

Faulty fan?

Fan might need more voltage than the motherboard gives it to start up?

Use a fan controller?

Get a new fan?

Have a look in the bios to change the threshold of the temps before it kkicks in?

[UseItNow]

Use a fan controller?

No.

Fan might need more voltage than the motherboard gives it to start up?
Have a look in the bios to change the threshold of the temps before it kkicks in?

Any idea where to look for in increasing the voltage, also didn't see anything in the P35C-DS3R (F2 Revision) bios relating to temp thresholds for kicking in the fan. Need a break.....

Faulty fan?

No, checked both Zalman ZM-F2 Fans, they work!
Rang Gigabyte, told that it might be their Smart Fan Control, disabled it, still underlying problem.

However, I've noticed that the fan starts up just as the monitor beeps and the POST occurs, this is slightly after the power button has been pressed - about 2-5 seconds.
Another thing is that after ringing Gigabyte, they told me that I should try inserting the fan header into the PWR FAN header and try, see if the fan spins up immediately upon power-up. Guess what? IT DOES, THERE'S NO DELAY!

So I tried the other fan in the CPU FAN header, keeping the fan in the PWR FAN header, guess what?
The PWR FAN spun up immediately whilst the CPU FAN started up a few seconds later, just as POST occurs.

Gigabyte also told me that it shouldn't be a problem in leaving the CPU fan in the PWR FAN header with nothing in the CPU FAN header, it should boot. Is this true? I guess there's also the added knowledge of that there's thermal protection on the CPU (E6750)? Where the power will be cut off in case of overheating?

However, I don't feel comfortable in doing this, I would like to pinpoint the reason as to why this is happening, unless of course this is something everybody else is seeing in their system with Gigabyte motherboards, specifically the P35C-DS3R.

However, if I can't locate the problem should there be concern if I was to leave the fan in the CPU FAN header and face the delay in spin-up, could this reduce the lifespan of the CPU? Or would it be better for me to leave it in the PWR FAN header and use the PC with that fan header configuration?

Get a new fan?

Having tried that, I guess I could try a different fan with a 4-pin connection, as the Zalman ZM-F2 has a 3-pin connector. Say with the PWM feature, could this possibly have an effect? Any recommendations?

I'm sorry in going on for so long but you can underdstand my frustration, if it didn't post, OK (touch wood) but to POST and install XP Professional without any problems and pass Memtest (1 hour), Prime95 (1 hour) and run FutureMark 3D 2005 succesfully. Okay, not the longest of test runs but still an indication of everything else seems fine?

ALL HELP, COMMENTS, RECOMMENDATIONs, HOWEVER TRIVIAL, APPRECIATED!

Thank you for your time!