PC Case rear fan

May i suggest that you try to slightly lower the System Fan speed (not CPU fan)? As for my bios, i can see 100%, 82.5%, 75% and so on.

I set mine as 75% and the sys_fan becomes less noisy. I'm running a CoolerMaster 120mm on rear of case btw, on a Centurion 5 tower case.

And also please take note of the temperature of your CPU and Case when you change the speed just in case you get into overheating problems!

When I built my new system I used four of these guys.

Newegg.com - Antec 761345-75081-3 80mm Case Fan - Case Fans

They have a selector switch for 3 speeds but its on a short lead and inside the case so not convenient to change.

Then I got this guy to control my 4 case fans. Works by controlling the voltage to the fans. Will control 5 fans and also has 5 temperature probes and temp alarm. One feed from power supply to controller and fans feed from the controller. I normally run my fans at 50% and all is cool.

Newegg.com - NZXT Sentry-2 5.25" Touch Screen fan controller - Controller Panels

Newegg has lots of fans and also other fan controllers. Look at the CFM and dBa (noise) ratings.

Jim

Excellent thanks for the advice everyone. I will do a little shopping investigation and try one out :)