Intel XTU - What are the differences between Thermal, Power Limit & Current Limit Throttling ?

Hello guys,

As all of you, I have a Alienware 2015 with a GTX 980m. I am really happy with this laptop because the temps never get too hot. I have a Notepal U3 and never go above 80°C : max for the moment was 77°C.

I have never really paid attention to throttling since the games I play do not need too many ressouces (Dota, Pillars of Eternity, Max Payne 3, USF4...) but I started to be interested in how my laptop performs with summer time coming.

Everything is in the title : what are the differences between Thermal, Power Limit & Current Limit Throttling ?

Indeed, under intel XTU, when I do a benchmark test, my PowerLimit Throttling and Current Limit Throttling are constantly moving. My Thermal Throttling stays at 0% though.



Can anybody explain me what this means ? Do I have some throttling issue ?
My CPU is also constantly moving from 3 to 3,5 GHZ but never under. Is that also normal that the CPU usage % is never constant ? (ie 100% ??).

Thx a lot guys in advance for your responses.

 

Best way to check if its throttling by running wprime95 and Heaven

 

Thank you for the response.

Actually, my Throttling comes from the power limit which is reached.

Can anybody tell me why ? Because I got a 240W PSU, which should be enough to feed the laptop, how can I be limited because of the TDP ?

In other words, is it normal ?

Thx a lot !

 

To address (most of) your questions,

CPU usage % is never constant, unless under load (e.g. CPU stress test).

Thermal throttling = reduced CPU speed due to heat.
My A15 (980m) never had this, although YMMV.

Power limit throttling = limiting CPU speed to its rated TDP.
i7 4710/4720/4980HQ have the same TDP of 47w, but often need to go above that.
If you really want full performance, set "Turbo Boost Power Max" to 58w (consider undervolting).

However, my experience by setting it to 58w: Bios A00 = noisy, A05 = toasty.
Not worth it either way, but it lets you maintain a steady turbo boost.
IMHO, 28w/37w is perfectly good for gaming without any noise/heat concerns.

Not too familiar with current limit throttling, so can't help you out there, sorry.
P.S: You can also adjust the Active Core multipliers for more MHz.

 

Thx Xenow for your message !

That helped me a lot to understand a bit more about those throttling ;D !

 

Where do you set the wattage settings that you were referring to here?

 

Under XTU it's "Turbo Boost Power Max", under Advanced Tuning tab - between CPU voltage and core multipliers.