Subject: P4 Sleep State
By: Slemaker (IP: 68.4.118.*)
Written on: 08-09-2005 02:00

I need advice from someone familiar with internal technical details of the Pentium 4 CPU.

The P4 has a circuit which "shuts the CPU off" if a very high temperature is detected. It is automatic and does not involve any software. I suspect that the bus signal THERMTRIP# causes the CPU to drop into a SLEEP or DEEP SLEEP state. My question #1: If the CPU goes into a SLEEP/DEEP-SLEEP state in the midst of normal operation, would I see the following?

(1) Complete absence of any sign of activity other than continued spinning of the hard disks and fans;
(2) Complete nonresponsiveness to any user action (mouse, key presses, even pressing the power-off button uinless held for 5 seconds or longer);
(3) All visible indications (screen display, indicator LEDs) frozen in the exact state occupied at the instant that the SLEEP/DEEP-SLEEP state was entered - in other words, the screen continues to display desktop and application displays (frozen), not a blue, dark, or corrupted screen.

Finally, what circumstances other than an extreme over-temp condition can cause such a switch to SLEEP/DEEP-SLEEP?


By: Tillmann (IP: 146.140.7.*)
Written on: 13-09-2005 15:33


if the P4's overtemperature protection is activated, the CPU is SLOWED DOWN, not halted. That is, the system will continue to work, only much, much slower than before.

What you're describing are rather the symptoms of a normal crash. Reasons may include poor operating system/driver configuration, hardware defects (bad memory, motherboard, ...), hardware/software compability issues. It may also be that the motherboard is overheating and therefore crashing; however in the case of the P4, it is unlikely that crashing is a symptom of CPU overheating. What CPU temperature does the BIOS report?

Back to index | Reply to this message

Forum software based on code ©