OC & TDP

[Erif]

Hi all,

My friend has a motherboard that supports max 95W processors.

Now he is going for a processor with 95W TDP, and is thinking of OCing it.

Will OCing affect the TDP of the processor? Will his system become unstable?

 

[BonzaiDuck]

Originally posted by: Erif
Hi all,

My friend has a motherboard that supports max 95W processors.

Now he is going for a processor with 95W TDP, and is thinking of OCing it.

Will OCing affect the TDP of the processor? Will his system become unstable?

I try and be modest when "I think I know sumpin'." My associates here can correct me, but I'm pretty sure of this.

Thermal energy dissipated by the CPU increases with the square of the (VCORE) voltage, and linearly with the increase in speed (Mhz). In the first case, the thermal wattage increases like an exponential or parabolic curve with added voltage; in the second case, it only rises in a straight-line relationship with speed.

Either way, the thermal wattage at load will be higher than the TDP-spec, which -- I understand -- is the load thermal wattage for a processor run under stock specs and settings.

I don't know how OC'ing would affect the motherboard. Are you saying that the mobo supports a range of processors that have among them a maximum TDP spec that is 95W? That wouldn't have anything to do with the motherboard -- per se.

All components have varying increased risk of failure under various over-clocking scenarios, but increasing the thermal wattage of the processor by over-clocking it shouldn't pose a thermal risk to the motherboard with adequate cooling. The motherboard has its own specs in terms of voltage, thermal wattage and speed, and those specs may exceed those of the processor: some boards are "made for overclocking." The same holds true for RAM kits -- their voltages and power usage (which generate heat), and speed settings.

Others invited to comment here . . . .

 

[veri745]

Motherboards usually have a max TDP processor supported due to the traces on the PCB being rated for a maximum current. If you push the processor too hard on a weak motherboard, the current being draw through the Vcore traces can overheat and potentially melt/burn out. So yes, there is a danger; I'm not sure how hard your friend in considering pushing his processor, but the motherboard should definitely be able to handle a reasonable overclock.

Like BonzaiDuck said, increasing the freq. without bumping Vcore is safer that increasing Vcore.

 

[ghost recon88]

Whenever you increase clock speed or voltage, you increase TDP. However just because the motherboard is rated for 95w max on the TDP, doesn't mean it can't handle more then that if you overclock

 

[alyarb]

The TDP is a target number set by the manufacturer and only serves to approximate power consumption of a chip so that an ecosystem of thermally compatible parts can be designed around this target. Increasing the frequency and/or voltage of the part will increase this power consumption. You aren't changing TDP because it's an imaginary number to begin with. Setting certain BIOS parameters out of spec such as your bus speed and core voltage will likely result in an actual consumption that is in excess of the manufacturer's TDP, but to everyone's chagrin the chip is not damaged in any way and operates faster. Overclocking is one way to exceed your TDP.

Peak power consumption of most CPUs actually falls a couple watts short of their TDP, while they generally spend their entire lives far away from that number.

 

[Erif]

I think I've got a fairly good idea now.

Thanks everyone.