rMBP Throttling in Bootcamp

[TheMental]

I've been an avid reader of this forum and it has helped me a lot before, so I come to you folks as a last resort.

I have an early 2013 rMBP, i7-3740QM @ 2.7GHz - GT650m - 16Gb ram - > All games that it could realistically run were running just fine up until like 2 month ago, no throttling issues whatsoever.

But, summer hit and I started getting real annoying CPU and GPU throttles. I couldn't really run any game on it during that time, and I pretty much assumed it has to be dust/fans/thermal paste issues. So, I sent it to a shop where they cleared out all the dust, and reapplied thermal paste, and it worked fine for about a month.

A month after the cleaning process, performance started to decline, but it wasn't really that annoying or game breaking so I just disregarded it.

Now, the same problems are happening again. GPU is throttling down to 270 MHZ, CPU revolves around the 2GHz range even when set to 2.7GHz constant with ThrottleStop and under load, etc..

I also tried tweaking performance states in inspector but nothing worked really. Attached are the sensor readings during throttling and a dxdiag.

It's also worth noting that before, both cpu and gpu temps would go up as far as 99C and no throttling would occur. Now the throttling appears to be happening at 70C. I'm not really sure what's going on.

Fans are set to max value using Macs Fan Control.

Thanks for taking the time to read this, and any suggestion you might have is heavily appreciated.

 

[snaky69]

Reset the SMC and report back.

 

[TheMental]

Reset the SMC and report back.

Just did, zero change.

 

[cbautis2]

Check how hot your power brick gets when gaming. I'm assuming that the power brick isn't providing maximum power delivery due to excessive heat when gaming

 

[IanKelleigh]

Check how hot your power brick gets when gaming. I'm assuming that the power brick isn't providing maximum power delivery due to excessive heat when gaming

I've seen this happen on my MacBook pro too. So you're saying that if the brick gets too hot, it's not delivering enough power, so the CPU/GPU get throttled?

 

[cbautis2]

I've seen this happen on my MacBook pro too. So you're saying that if the brick gets too hot, it's not delivering enough power, so the CPU/GPU get throttled?

Yep. The EFI is smart enough to modulate the frequencies of the CPU and GPU as to meet the maximum power output of the power brick. To fully test this hypothesis try putting cold packs to the power brick then monitor the CPU and GPU temps.

 

[TheMental]

Check how hot your power brick gets when gaming. I'm assuming that the power brick isn't providing maximum power delivery due to excessive heat when gaming

Well, I checked it and it seems as warm as usual. I never cared to check it too much before, but it doesn't seem to be boiling hot or anything.

I did however unplug the adapter completely and went on battery, didn't make a difference.

 

[TheMental]

Update: Not sure if this is relevant, but if the battery is charging the throttling seems to be happening a lot more frequently. The keyboard seems to feel relatively hot during the throttling issues, yet all temps seem to be revolving around 65-70c.

Are my sensors broken or sth? Wow this is frustrating!

 

[shoehornhands]

From the info you've given, it sounds more likely to be an issue related to the GPU.

If the GPU runs slower in the summer (the increase in air temperature reduces cooling), then the CPU isn't going to have as much work to do (i.e. the GPU is the weakest link, not the CPU). Because of this, the CPU has no need to utilize turbo (the i7-3740QM can turbo up to 3.7GHz) and this is what brings the temp up to 99°C (that's the whole point of turbo; to give you more speed when the cooling system isn't saturated).

In other words, if the GPU is throttling, then the CPU will look like it's throttling as well (because it has less work to do and thus doesn't need to run as fast). This is evidenced by the CPU "appearing" to throttle at 70°C.

I don't know all the specifics of the GT 650m, but its specifications say "up to" 900MHz core clock speed and I didn't see any mention of a base clock. I would try playing around with the GPU a bit (dropping the max core clock may actually result in smoother gameplay by eliminating the peaks and valleys in framerate).

Also, keep in mind all the changes you make trying to solve the problem (i.e. settings you change related to the processor, gpu, clocks, power states etc). Given that everything is interrelated, it's not uncommon to come across the solution to a problem, but be unaware of it because something else you tweaked (while attempting to solve the initial problem), actually resulted in a similar problem.

 

[TheMental]

From the info you've given, it sounds more likely to be an issue related to the GPU.

If the GPU runs slower in the summer (the increase in air temperature reduces cooling), then the CPU isn't going to have as much work to do (i.e. the GPU is the weakest link, not the CPU). Because of this, the CPU has no need to utilize turbo (the i7-3740QM can turbo up to 3.7GHz) and this is what brings the temp up to 99°C (that's the whole point of turbo; to give you more speed when the cooling system isn't saturated).

In other words, if the GPU is throttling, then the CPU will look like it's throttling as well (because it has less work to do and thus doesn't need to run as fast). This is evidenced by the CPU "appearing" to throttle at 70°C.

I don't know all the specifics of the GT 650m, but its specifications say "up to" 900MHz core clock speed and I didn't see any mention of a base clock. I would try playing around with the GPU a bit (dropping the max core clock may actually result in smoother gameplay by eliminating the peaks and valleys in framerate).

Also, keep in mind all the changes you make trying to solve the problem (i.e. settings you change related to the processor, gpu, clocks, power states etc). Given that everything is interrelated, it's not uncommon to come across the solution to a problem, but be unaware of it because something else you tweaked (while attempting to solve the initial problem), actually resulted in a similar problem.

That's the thing, it used to always run at 900 MHz when its not throttling, these days it rarely ever goes up to 900, stays at 725 or something and then when it starts throttling it goes down to 270. If you check the actual sensor logs, you'd see that the GPU itself is in fact throttling at 70C, and the CPU temp is around the same too. There's also minor CPU throttling going on.

I'm forcing Turboboost off anyway using throttle stop, so its not turbo boost thats NOR over heating thats causing my issues. This card used to run fine as I said in 90+ on both CPU and GPU. Now, everything is weird all of a sudden.

I am using a cooling pad for the laptop btw, and even when there is no throttling going on the GPU will never go up to 900 or whatever speed I set above 725.

 

[cbautis2]

Update: Not sure if this is relevant, but if the battery is charging the throttling seems to be happening a lot more frequently. The keyboard seems to feel relatively hot during the throttling issues, yet all temps seem to be revolving around 65-70c.

Are my sensors broken or sth? Wow this is frustrating!

I would try getting a new magsafe at a local store and see if it helps. You can return the magsafe if it made no difference...

 

[Freyqq]

Buy a $20 cooling pad for the rMBP. A decent one will cool temps by about 10C, which is usually enough to prevent throttling.

 

[TheMental]

Buy a $20 cooling pad for the rMBP. A decent one will cool temps by about 10C, which is usually enough to prevent throttling.

Already using one. And my temps under load used to revolve around 85-90C without any throttling. Now both the GPU and CPU appears to be throttling at 70C.

 

[Freyqq]

Already using one. And my temps under load used to revolve around 85-90C without any throttling. Now both the GPU and CPU appears to be throttling at 70C.

could be a driver or firmware issue then. Are you using the latest GPU drivers from nvidia's site?

 

[TheMental]

could be a driver or firmware issue then. Are you using the latest GPU drivers from nvidia's site?

Yep, latest drivers.

 

[Kissmyne]

This sounds like the GPU is not able to dissipate heat very well and is throttling as a result of this physical issue.

I would suggest testing in OS X, with Unigine Heaven or similar, if the GPU temps climb over 95 degrees Celsius running this benchmark, you have a hardware issue, namely overheating which would explain the throttling.

 

[TheMental]

This sounds like the GPU is not able to dissipate heat very well and is throttling as a result of this physical issue.

I would suggest testing in OS X, with Unigine Heaven or similar, if the GPU temps climb over 95 degrees Celsius running this benchmark, you have a hardware issue, namely overheating which would explain the throttling.

I sent it to the shop today, and they sent it back saying the heat sink "isn't working properly" and I need to order a new heat-sink with two fans, setting me back $600 and 32 days (time for the parts to arrive).