CPU temperature

power supply calculator:
extreme.outervision.com/PSUcalculatorlite
Source 
Voltage and the Current draw at that Voltage and the ability to dissipate the heat.. You pretty much determine the voltage if you alter it from the BIOS determined value (Based on CPU)
So the varable is current. The current is based on several varaibles. (1) work down by the CPU based on what you + background programs are doing (Can Find % of CPU utilization. The freq used by the CPU ( stock vs OCed). Think of the CPU as a RCL circuit (RCL = Risistance, capacitance, inductive) When Freq goes up R - no effect, Xc (AC Resistance of a capacitor) goes Down, Xl (AC Resistance of an inductor) goes up. The bottom line here is that as Freq goes up the CPU Impeadeance (Fancy name for AC resistance) goes Down = Higher Current. The Temp also has an effect. IF Modern CPUs did not shut down above a given temp a condition called thermal runaway could occur. Semiconductors have a negative temp coeffient (As Temp goes Up R goes down). This means thas as the temp hits a given point the resistance goes down, so Current goes up causing MORE heat, R goes down more, I goes up more untill it goes POOF and gives that burning oder.
Power = Current x Voltag and Voltage = Current / Resistance
==========================
Source (Excerpts)
Cases: Avoiding Overheating
Typical Assembling Problems 
How to Correctly Apply Thermal Grease
Motherboard Monitor and Hardware Sensors Monitor at:
http://www.hardwaresecrets.com/page/download_overclock
PCWizard
Everest - Monitor for PC and MAC
SpeedFan


--------------------------------
Water Cooling
Athlon XP Overclocking Tape
Athlon 64 Overclocking
Pentium 4 Thermal Throttle
How to Correctly Assemble PCs with Pentium 4 Prescott
Intel CPU Temperatures

• Core Duo: 100º C
• Core Solo: 100º C
• Pentium M: 100º C
• Core 2 Duo:

Model	Clock	Max. Temp. (º C)
E6850	3 GHz	72
E6750	2.66 GHz	72
E6700	2.66 GHz	60.1
E6700	2.66 GHz	60.1
E6600	2.40 GHz	60.1
E6600	2.40 GHz	60.1
E6550	2.33 GHz	72
E6540	2.33 GHz	72
E6420	2.13 GHz	60.1
E6400	2.13 GHz	61.4
E6400	2.13 GHz	61.4
E6320	1.86 GHz	60.1
E6300	1.86 GHz	61.4
E6300	1.86 GHz	61.4
E4500	2.20 GHz	73.3
E4400	2 GHz	61.4
E4400	2 GHz	73.3
E4300	1.8 GHz	61.4

• Core 2 Quad:

Model	Clock	Max. Temp. (º C)
Q6700	2.66 GHz	71
Q6600	2.4 GHz	62.2
Q6600	2.4 GHz	62.2

• Core 2 Extreme:

Model	Clock	Max. Temp. (º C)
QX6850	3 GHz	64.5
QX6800	2.93 GHz	64.5
X6800	2.93 GHz	60.4
QX6800	2.93 GHz	64.5
X7900	2.80 GHz	100
X7900	2.80 GHz	100
QX6700	2.66 GHz	65
X7800	2.60 GHz	100

• Pentium Dual Core:

Model	Clock	Max. Temp. (º C)
E2180	2 GHz	73.2
E2160	1.8 GHz	73.2
E2160	1.8 GHz	61.4
E2140	1.6 GHz	61.4
E2140	1.6 GHz	61.4
T2080	1.73 GHz	100
T2060	1.60 GHz	100

• Pentium D:

Model	Clock	Max. Temp. (º C)
960	3.60 GHz	63.4
960	3.60 GHz	68.6
950	3.40 GHz	63.4
950	3.40 GHz	63.4
945	3.40 GHz	63.4
945	3.40 GHz	63.4
950	3.40 GHz	68.6
940	3.20 GHz	63.4
940	3.20 GHz	68.6
935	3.20 GHz	63.4
925	3 GHz	63.4
930	3 GHz	63.4
930	3 GHz	63.4
925	3 GHz	63.4
915	2.80 GHz	63.4
915	2.80 GHz	63.4
920	2.80 GHz	63.4
840	3.20 GHz	69.8
840	3.20 GHz	69.8
830	3 GHz	69.8
830	3 GHz	69.8
820	2.80 GHz	64.1
820	2.80 GHz	64.1
805	2.66 GHz	64.1

• Pentium Extreme Edition:

Model	Clock	Max. Temp. (º C)
965	3.73 GHz	68.6
955	3.46 GHz	68.6
840	3.20 GHz	69.8

• Pentium 4 Extreme Edition:

Model	Clock	Max. Temp. (ºC)
SL7Z4	3.73 GHz	72.8
SL7RT	3.46 GHz	66
SL7NF	3.46 GHz	66
SL7RR	3.40 GHz	66
SL7GD	3.40 GHz	66
SL7CH	3.40 GHz	67

Maximum-CPU-Temperature Pentium 4 (more)
Maximum-CPU-Temperature Celerons
Maximum-CPU-Temperature all Xeons

AMD CPU Temperatures

• Athlon 64:

OPN	Model	Clock	Max. Temp. (ºC)
ADA4000IAA4DH	4000+	2.6 GHz	69
ADA4000DEP5AS	4000+	2.4 GHz	70
ADA4000DAA5BN	4000+	2.4 GHz	71
ADA4000DKA5CF	4000+	2.4 GHz	71
ADA4000DEP5AS	4000+	2.4 GHz	70
ADA3800IAA4CN	3800+	2.4 GHz	69
ADA3800DAA4BW	3800+	2.4 GHz	71
ADA3800DEP4AS	3800+	2.4 GHz	70
ADA3800DEP4AW	3800+	2.4 GHz	70
ADA3800DAA4BP	3800+	2.4 GHz	70
ADH3800IAA4DE	3800+	2.4 GHz	65
ADA3800IAA4DH	3800+	2.4 GHz	69
ADA3700AEP5AR	3700+	2.4 GHz	70
ADA3700DKA5CF	3700+	2.2 GHz	71
ADA3700DAA5BN	3700+	2.2 GHz	70
ADA3500IAA4CN	3500+	2.2 GHz	69
ADA3500IAA4CW	3500+	2.2 GHz	70
ADD3500IAA4CN	3500+	2.2 GHz	78
ADA3500DKA4CG	3500+	2.2 GHz	65
ADA3500DAA4BN	3500+	2.2 GHz	65
ADA3500DAA4DW	3500+	2.2 GHz	65
ADA3500DEP4AS	3500+	2.2 GHz	70
ADA3500DEP4AW	3500+	2.2 GHz	70
ADA3500DIK4BI	3500+	2.2 GHz	70
ADA3500DAA4BP	3500+	2.2 GHz	70
ADH3500IAA4DE	3500+	2.2 GHz	65
ADA3500IAA4DH	3500+	2.2 GHz	69
ADA3400AEP4AR	3400+	2.4 GHz	70
ADA3400AEP4AX	3400+	2.4 GHz	70
ADA3400AIK4BO	3400+	2.2 GHz	65
ADA3400AEP5AP	3400+	2.2 GHz	70
ADA3400AEP5AR	3400+	2.2 GHz	70
ADA3200AEP4AR	3200+	2.2 GHz	70
ADA3200AEP4AX	3200+	2.2 GHz	70
ASA3200AIO4BX	3200+	2.2 GHz	69
ADA3200DEP4AW	3200+	2.0 GHz	70
ADA3200DIK4BI	3200+	2.0 GHz	70
ADA3200DAA4BP	3200+	2.0 GHz	70
ADA3200AEP5AP	3200+	2.0 GHz	70
ADA3200AEP5AR	3200+	2.0 GHz	70
ADA3200DKA4CG	3200+	2.0 GHz	65
ADA3200DAA4BW	3200+	2.0 GHz	65
ADA3000AEP4AP	3000+	2.0 GHz	70
ADA3000AEP4AR	3000+	2.0 GHz	70
ADA3000AEP4AX	3000+	2.0 GHz	70
ADA3000AIK4BX	3000+	2.0 GHz	70
ADA3000DEP4AW	3000+	1.8 GHz	70
ADA3000DIK4BI	3000+	1.8 GHz	70
ADA3000DAA4BP	3000+	1.8 GHz	70
ADA3000DAA4BW	3000+	1.8 GHz	65
ADA3000IAA4CN	3000+	1.8 GHz	69
ADA2800AEP4AP	2800+	1.8 GHz	70
ADA2800AEP4AR	2800+	1.8 GHz	70
ADA2800AEP4AX	2800+	1.8 GHz	70

• Athlon 64 FX:

OPN	Model	Clock	Max. Temp. (º C)
ADAFX74GAA6DI	FX-74	3 GHz	56
ADAFX72GAA6DI	FX-72	2.8 GHz	63
ADAFX70GAA6DI	FX-70	2.6 GHz	63
ADAFX62IAA6CS	FX-62	2.8 GHz	63
ADAFX60DAA6CD	FX-60	2.6 GHz	65
ADAFX57DAA5BN	FX-57	2.8 GHz	65
ADAFX55DAA5BN	FX-55	2.6 GHz	65
ADAFX55DEI5AS	FX-55	2.6 GHz	63
ADAFX53CEP5AT	FX-53	2.4 GHz	70
ADAFX53DEP5AS	FX-53	2.4 GHz	70
ADAFX51CEP5AT	FX-51	2.2 GHz	70
ADAFX51CEP5AK	FX-51	2.2 GHz	70

• Athlon 64 X2:

OPN	Model	Clock	Max. Temp. (º C)
ADX6400CZWOF	6400+	3.2 GHz	63
ADX6000IAA6CZ	6000+	3.0 GHz	63
ADA5600IAA6CZ	5600+	2.8 GHz	70
ADA5400IAA5CZ	5400+	2.8 GHz	70
ADO5200IAA6CZ	5200+	2.6 GHz	72
ADA5200IAA6CS	5200+	2.6 GHz	70
ADO500DSWOF	5000+	2.6 GHz	72
ADO5000IAA6CZ	5000+	2.6 GHz	72
ADO5000IAA5DD	5000+	2.6 GHz	70
ADA5000IAA5CS	5000+	2.6 GHz	70
ADO5000IAA5CU	5000+	2.6 GHz	70
ADO4800IAA5DD	4800+	2.5 GHz	72
ADA4800IAA6CS	4800+	2.4 GHz	70
ADO4800IAA6CS	4800+	2.4 GHz	72
ADA4800DAA6CD	4800+	2.4 GHz	65
ADO4600IAA5CZ	4600+	2.4 GHz	72
ADO4600IAA5CU	4600+	2.4 GHz	72
ADA4600IAA5CU	4600+	2.4 GHz	70
ADA4600DAA5CD	4600+	2.4 GHz	65
ADA4600DAA5BV	4600+	2.4 GHz	65
ADO4400IAA5DD	4400+	2.3 GHz	72
ADV4400DAA6CD	4400+	2.2 GHz	71
ADA4400IAA6CS	4400+	2.2 GHz	70
ADO4400IAA6CS	4400+	2.2 GHz	72
ADA4400DAA6CD	4400+	2.2 GHz	65
ADA4200IAA5CU	4200+	2.2 GHz	70
ADO4200IAA5CU	4200+	2.2 GHz	72
ADA4200DAA5CD	4200+	2.2 GHz	71
ADA4200DAA5BV	4200+	2.2 GHz	65
ADH2350IAA5DD	BE-2350	2.1 GHz	78
ADO4000IAA5DD	4000+	2.1 GHz	72
ADA4000IAA6CS	4000+	2 GHz	70
ADO4000IAA6CS	4000+	2 GHz	72
ADO3800IAA5CZ	3800+	2 GHz	72
ADA3800IAA5CU	3800+	2 GHz	70
ADO3800IAA5CU	3800+	2 GHz	72
ADD3800IAT5CU	3800+	2 GHz	78
ADA3800DAA5BV	3800+	2 GHz	71
ADA3800DAA5CD	3800+	2.0 GHz	71
ADO3600IAA5DD	3600+	1.9 GHz	72
ADH2300IAA5DD	BE-2300	1.9 GHz	78

• Sempron Soquete 462: 90º C
• Sempron Soquete AM2:

OPN (Tray)	OPN (Box)	Model	Clock	Max. Temp. (ºC)
SDH1150IAA3DE	SDH1150DEBOX	LE-1150	2 GHz	61-79
SDA3800IAA3CN	SDA3800CNBOX	3800+	2.2 GHz	55-69
SDA3600IAA3CN	SDA3600CNBOX	3600+	2 GHz	55-69
SDA3500IAA2CN	SDA3500CNBOX	3500+	2 GHz	55-69
SDD3500IAA2CN	SDD3500CBNOX	3500+	2 GHz	78
SDA3400IAA3CN	SDA3400CNBOX	3400+	1.8 GHz	55-69
SDA3400IAA3CW	SDA3400CWBOX	3400+	1.8 GHz	55-69
SDD3400IAA3CN	SDD3400CBNOX	3400+	1.8 GHz	78
SDA3200IAA2CN	SDA3200CNBOX	3200+	1.8 GHz	55-69
SDD3200IAA2CN	SDD3200CNBOX	3200+	1.8 GHz	78
SDA3200IAA2CW	SDA3200CWBOX	3200+	1.8 GHz	55-69
SDA3000IAA3CN	SDA3000CNBOX	3000+	1.6 GHz	55-69
SDD3000IAA3CN	SDD3000CNBOX	3000+	1.6 GHz	78
SDA2800IAA2CN	SDA2800CNBOX	2800+	1.6 GHz	55-69

• Sempron Soquete 754:

OPN (Tray)	OPN (Box)	Model	Clock	Max. Temp. (ºC)
SDA3400AIO3BX	SDA3400BXBOX	3400+	2 GHz	69
SDA3300AIO2BO	SDA3300BOBOX	3300+	2 GHz	69
SDA3300AIO2BX	SDA3300BXBOX	3300+	2 GHz	69
SDA3300AIO2BA	SDA3300BABOX	3300+	2 GHz	70
SDA3300AIO2BA	SDA3300CVBOX	3300+	2 GHz	70
SDA3100AIO3BA	SDA3100CVBOX	3100+	1.8 GHz	70
SDA3100AIP3AX	SDA3100AXBOX	3100+	1.8 GHz	70
SDA3100AIO3BA	SDA3100BABOX	3100+	1.8 GHz	70
SDA3100AIO3BO	SDA3100BOBOX	3100+	1.8 GHz	69
SDA3100AIO3BX	SDA3100BXBOX	3100+	1.8 GHz	69
SDA3000AIO2BA	SDA3000CVBOX	3000+	1.8 GHz	70
SDA3000AIO2BO	SDA3000BOBOX	3000+	1.8 GHz	69
SDA3000AIO2BX	SDA3000BXBOX	3000+	1.8 GHz	69
SDA3000AIP2AX	SDA3000AXBOX	3000+	1.8 GHz	70
SDA3000AIO2BA	SDA3000BABOX	3000+	1.8 GHz	70
SDA2800AIO3BA	SDA2800BABOX	2800+	1.6 GHz	70
SDA2800AIO3BA	SDA2800CVBOX	2800+	1.6 GHz	70
SDA2800AIO3BO	SDA2800BOBOX	2800+	1.6 GHz	69
SDA2800AIO3BX	SDA2800BXBOX	2800+	1.6 GHz	69
SDA2600AIO2BA	SDA2600BABOX	2600+	1.6 GHz	70
SDA2600AIO2BA	SDA2600CVBOX	2600+	1.6 GHz	70
SDA2600AIO2BX	SDA2600BXBOX	2600+	1.6 GHz	69
SDA2600AIO2BO	SDA2600BOBOX	2600+	1.6 GHz	69
SDA2500AIO3BX	SDA2500BXBOX	2500+	1.4 GHz	69

Maximum-CPU-Temperature Opterons
Maximum-CPU-Temperature More Opterons

Source
Intel CPU temperatureIntel have an inbuilt thermal protection system allowing the CPU to reach temp's above 100 and still be fine. But this does not mean you should allow this to go on for a long time.
Idle: 40 - 55 Load : 55 - 85
(intels are known for running hot so dont stress too much unless your close to 100 or so, you can setup alerts for when your CPU hits a certain temp)
AMD CPU temperatureIdle: 30 - 45 Load: 50 - 70 

Reasons CPU is overheating

It is not uncommon for a CPU to run hot and usually it is quite an easy fix the following are the most common reasons
1. Thermal Paste underneath your CPU has been applied poorly and not in a nice thing layer, if this is the case you can simply go out and buy some more , its very cheap and look for a thermal paste that comes with a brush to make applying it easier.
2. Your CPU needs a desperate clean and is clogged with dust , this is very common in old houses that get dusty easily, simply clean it out with a brush or can of compressed air. My secret method , cheap method is too use a simple manual foot pump for a swisse ball.... works great and cheaper than buying cans of compressed air.
3. You CPU cooling system has not been fitted properly or is generally poor, this being said the stock fan's that come with CPU's are usually adequate aslong as you aren't overclocking or doing anything extreme.

Signs of High Temperature on CPURunning your CPU constantly at a high temperature can be very damaging and may have the following implications
- Reduce the Life of your CPU
- Randomly Freezes or Resets your computer
- CPU totally burns out (this would take some time, at very high temps to occur, remember intel cpu temperature can get very hot especially prescott series)
Another great way to monitor your cpu temperature is to include desktop widgets to monitor your CPU temp at all times.
Let me know if you have any questions as I've played around with CPU temperatures a lot overclocked a few CPU's and have setup some watercooling too cool some of the hotter CPU's. goodluck :)