I have HP Z640 with the newest M60 02.50 BIOS (sp100084.exe). Automatic fan speed control does not work. So when I run heavy CPU load SW (ie. render 3DS Max) which runs for 10 hours at 100% CPU load, then CPUs have 89°C (192 degrees Fahrenheit). CPU fan speed does not change - still the same (1300 rpm). When I set "Idle fan speed" to maximum in BIOS, then they have about 5000 rpm. With such high rpm even I run 100% load on CPUs for hours, they does not exceed 50°C (122 degrees Fahrenheit). I made a warranty claim at HP. They changed some parts - new motherboard, new fans on rear case wall, new USB module on the front case wall. It did not solve the problem. Fan speed regulation based on temperature (CPU load) stopped workig. I think it is due to BIOS update. I tried to downgrade to previous M60 02.48 BIOS (sp96293.exe). It did not help. And I can't find older BIOS version to try them. Anyone has idea? Any help kindly appreciated. HP Z640 Workstation configuration: - 2x Intel Xeon E5-2690 v4 (14-core, 2.60 GHz) - 128 GB ECC RAM - 4x 512 GB SSD - NVIDIA Quadro M4000, 8GB GDDR5 1 664× CUDA graphic card
