It is currently Fri Aug 22, 2014 10:19 am

All times are UTC - 8 hours




Post new topic Reply to topic  [ 10 posts ] 
Author Message
 Post subject: How to detect/observe CPU power (thermal) throttling?
PostPosted: Thu Aug 09, 2012 2:33 am 
Offline

Joined: Wed Jun 13, 2007 10:12 am
Posts: 2859
Location: ITALY
Are AMD (and Intel, of course) CPUs supposed to scale down core their clock frequency/multipliers when any overheating occurs?

In case, is there any setting, method, technique, or software able to show those throttling occurrences in any case?

The question may look rather obvious, but seemingly I'm not able to actually detect any change in cores clock frequency (I've used AMD OverDrive 4.2.1, CPU-Z 1.57, RMClock 2.3.5 and Throttle Watch 2.02), expectedly due to thermal throttle (currently on three AMD 10h CPUs, Phenom II X4 980, Athlon II X4 605e, Athlon II X3 420e), up to 117° C reported core temps (I used two more tools, Core Temp and SpeedFan).

_________________
Regards,
Luca


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Sun Aug 19, 2012 2:24 pm 
Offline
*Lifetime Patron*

Joined: Tue May 15, 2007 1:39 am
Posts: 1924
Location: Finland
I'm not sure AMD throttles, to be honest, I know most if not all Intel CPUs do. If you can't see it even when the CPU gets that hot, it's probably not there. Would need to verify the feature exists.

_________________
Case: FD Define Mini
Parts: P8Z77-M Pro µATX, i5-3570K @stock, N650Ti-1GD5/OC, G.Skill 2x4/1600/CL9 DDR3U, Xonar DX, WD G 1 TB, m4 128 GB, RX-5300 PSU
Cooling: Noctua NH-U12P SE2 + Scythe SS PWM, 2x Noctua NF-P12
Extras: Eaton UPS, Dell 24" EIPS, Ducky kb, SteelSeries m, Synology DS213j NAS
idle & load: CPU 32 °C & 44 °C @ 300/600 & 600/800 RPM, GPU 35-65 °C @ 1200-1650 RPM


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 5:32 am 
Offline

Joined: Sun Jan 23, 2005 11:44 pm
Posts: 165
Location: London
Not sure about AMD, Ive only used this on i7.
But Ive used ThrottleStop in the past, there is also some good info on the ins and out of thermal throttling.

_________________
Case: P182, Fans: 4xNF-P12@800Rpm, MoBo: GA-EX58-UD4, CPU: i920, GPU: GV-N670OC-2GD, PSU: Seasonic 760 platinum, HDD: HD203WI, SSD: VTX4-25SAT3-128


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 7:15 am 
Offline
Site Admin

Joined: Sun Aug 11, 2002 3:26 pm
Posts: 11828
Location: Vancouver, BC, Canada
afaik, throttling is featured in all modern cpus -- for many years now. It came more or less in conjunction with heatspreaders. One obvious & simple way to detect is with an AC power meter -- total power draw starts yoyoing down & up as throttling begins when a steady state stress utility like prime95 is used.

_________________
Mike Chin,
Editor/Publisher, SPCR
Support SPCR with your donations!


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 10:08 am 
Offline

Joined: Mon May 16, 2011 11:23 am
Posts: 623
Location: Germany
Spoon Boy wrote:
Not sure about AMD, Ive only used this on i7.
But Ive used ThrottleStop in the past, there is also some good info on the ins and out of thermal throttling.


"Cool & Quiet" is AMD's name for throtteling technique.


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 10:46 am 
Offline
Site Admin

Joined: Sun Aug 11, 2002 3:26 pm
Posts: 11828
Location: Vancouver, BC, Canada
Pappnaas wrote:
"Cool & Quiet" is AMD's name for throtteling technique.

I don't think that's quite right. CnQ applies only in low power states, to reduce power in idle, much like Inte's Speedstep. This was adopted from Notebooks. Not sure if AMD (or Intel, for that matter) actually named the throttling-at-max-power utility.

_________________
Mike Chin,
Editor/Publisher, SPCR
Support SPCR with your donations!


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 12:24 pm 
Offline
Patron of SPCR

Joined: Wed Dec 15, 2004 12:00 pm
Posts: 3302
Location: Essex, England
Quote:
Not sure if AMD (or Intel, for that matter) actually named the throttling-at-max-power utility.


This thread has put doubt into my mind, I have never seen a CPU throttle for certain, i.e. I didnt have CPU-Z installed and watched the clock speeds whilst it was overheating, but I was quite certain that this feature was introduced first with the P4, and then the Athlon, and I would assume every CPU since.

Many BIOS's have a "CPU throttling option" with they typical options of 60C, 65C and 70C, I have always set it at 60C when given the choice - But I have never actually put this to the test, although I have known some laptops to slow down when their heat-sinks are clogged with dust, fluff and hair, but I still don't have any personal evidence......


Andy

_________________
Main PC, P180, CM Silent Pro 500M, i5 3570k @ 4.2Ghz, 8-GB @ 2,000MHz, 256 GB Samsung 830, 500-GB 7K500, MSI 660Ti Twin Frozr, PC is super quiet :o
Server, 6-TB RAID-5 array, + 2 x 2-TB backup drives, 380W Enermax Pro82+, 4x very quiet fans, positive pressure only, no exhaust fans
Living Room PC, 3500+, 2-GB RAM, HD501LJ


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 2:08 pm 
Offline

Joined: Sun Jan 23, 2005 11:44 pm
Posts: 165
Location: London
I found this handy info on Intel's way of controlling things when a CPU starts to cook its self, its a little technical and goes into a fair bit of detail.
Thermal-Management-Logic-and-Thermal-Monitor-Feature

The short version if you don't want to be bored by Intel documents, there are two basic ways CPU overheating is controlled,
one is PROCHOT (short for processor hot)
basically a single bit flag on each CPU die that gets tripped when the TCC (Thermal Control Circuit) limit (set by INTEL) is reached this pretty much just tells the board to cut power to the CPU.

The other methods and probably more relevant to the OP's question about lowering the frequency of the CPU are called TM and TM2, (Thermal Monitor,Thermal Monitor2)
Basicly TM changes the duty cycle of the internal processor clocks
And TM2 causes the processor to adjust its operating frequency (by dropping the bus-to-core multiplier to its minimum available value) and input voltage identification (VID) value. This combination of reduced frequency and VID results in a reduction in processor power consumption.

Erm sorry for the longish post i got a bit carried away :lol:

_________________
Case: P182, Fans: 4xNF-P12@800Rpm, MoBo: GA-EX58-UD4, CPU: i920, GPU: GV-N670OC-2GD, PSU: Seasonic 760 platinum, HDD: HD203WI, SSD: VTX4-25SAT3-128


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 2:30 pm 
Offline
Patron of SPCR

Joined: Wed Dec 15, 2004 12:00 pm
Posts: 3302
Location: Essex, England
Quote:
The short version if you don't want to be bored by Intel documents, there are two basic ways CPU overheating is controlled,
one is PROCHOT (short for processor hot)
basically a single bit flag on each CPU die that gets tripped when the TCC (Thermal Control Circuit) limit (set by INTEL) is reached this pretty much just tells the board to cut power to the CPU.

The other methods and probably more relevant to the OP's question about lowering the frequency of the CPU are called TM and TM2, (Thermal Monitor,Thermal Monitor2)
Basicly TM changes the duty cycle of the internal processor clocks
And TM2 causes the processor to adjust its operating frequency (by dropping the bus-to-core multiplier to its minimum available value) and input voltage identification (VID) value. This combination of reduced frequency and VID results in a reduction in processor power consumption.

Erm sorry for the longish post i got a bit carried away :lol:


Don't apologise for such a short and very, very sweet post.

The TM/TM2 rings some bells from the distant past, and I would love to have a system to torture to see it in action for myself, just because :twisted:


Andy

_________________
Main PC, P180, CM Silent Pro 500M, i5 3570k @ 4.2Ghz, 8-GB @ 2,000MHz, 256 GB Samsung 830, 500-GB 7K500, MSI 660Ti Twin Frozr, PC is super quiet :o
Server, 6-TB RAID-5 array, + 2 x 2-TB backup drives, 380W Enermax Pro82+, 4x very quiet fans, positive pressure only, no exhaust fans
Living Room PC, 3500+, 2-GB RAM, HD501LJ


Top
 Profile  
 
 Post subject: Re: How to detect/observe CPU power (thermal) throttling?
PostPosted: Mon Aug 20, 2012 4:27 pm 
Offline

Joined: Sun Jan 23, 2005 11:44 pm
Posts: 165
Location: London
I couldn't sleep thinking over what the OP was asking about,

Quote:
The question may look rather obvious, but seemingly I'm not able to actually detect any change in cores clock frequency (I've used AMD OverDrive 4.2.1, CPU-Z 1.57, RMClock 2.3.5 and Throttle Watch 2.02), expectedly due to thermal throttle (currently on three AMD 10h CPUs, Phenom II X4 980, Athlon II X4 605e, Athlon II X3 420e), up to 117° C reported core temps (I used two more tools, Core Temp and SpeedFan)


From what i can remember most software takes best guess approaches to measuring the true temperature of modern day CPU's speaking about Intel,
And i dare say it's the same for AMD, a quote from the documents of Realtemp.

Intel designed these temperature sensors to control thermal throttling and thermal shut down and for those purposes,
they tend to work excellent. They were never designed to be used to report accurate core temperatures.


So it's hard to know for sure when the TJmax (Intel) or TCase Max (AMD) is reached as TJMax (IDK about AMD) is not a clearly defined value.

If you wanted to know a best guess for when the CPU is throttling due to overheating you would be looking for the TJMax or TCase Max for that particular CPU,
AFAIK Core Temp like all other software uses a best approximation approach.

You would then have to use something like core temp to get a rough idea of what the CPU's TJMax or TCase Max is,
As well as using something like CPU-Z at the same time to view the clock multiplier, core voltage, and Frequency of the CPU.
Watch for these to drop when you get close (could be +-10c) to TJMax, TCase Max.

All the while running your favorite stress test, Personally i used IntelBurnTest works on AMD to.
But if i'm honest i would be very worried if any CPU reached 117° C :shock: like the OP said IDK if AMD run hot normally but there comes a point when
reducing the noise a PC makes can be taken to far if your going to cook you components due to lack of good air flow.

As for the other end of the scale like MikeC said AMD used to use C'n'Q I think they now call it P-States and for Intel its C-States,
but that's a hole other kettle of fish. :roll:

_________________
Case: P182, Fans: 4xNF-P12@800Rpm, MoBo: GA-EX58-UD4, CPU: i920, GPU: GV-N670OC-2GD, PSU: Seasonic 760 platinum, HDD: HD203WI, SSD: VTX4-25SAT3-128


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 8 hours


Who is online

Users browsing this forum: Google [Bot] and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group