MPro 17 5.3 CPU Throttling Issues

Heya, avid lurker here, previous Alienware owner now turned to the dark side and got a mac -or is it the other way around?

So before I yell BS at Apple Care Support I hope some of you mac owners could clarify some questions for me. The only thing different about the Macbook Pro 17 I have is the T9900 CPU (3.06ghz), well onto my "problem".

I recently installed Windows 7 on my MB (No OSX present on the HDD), used BootCamp3.0 drivers from my OSX DvD and updated those to 3.1, so all drivers for the Hardware under Windows 7 have been installed -everything working nifty.

My problem is whenever I tax my system to the max (Read 100% CPU usage) the two CPU cores quickly reach 100-104Degrees, the fans kick in, but little do they help, the system instead clocks the CPU frequency down to first 2.8->2.6->....ending up at 1.5Ghz -the fans do nothing, since it never goes back to 3.06Ghz unless I stop the cpu intensive task.
Meaning under full load I can only utilize "~50%" of the power in my system. Do any of you have an idea why this happens? Its important to add that the MB is sitting on a flat table in a normally tempd. room, also the MB was bought October'09 so it is probably not dust clogging the fans.

I found this odd and called Apple Care, their reason for this was a defect HDD, which quite frankly doesn't make any sense. So I need some new ammo for those guys, any suggestions what could be wrong? Returning it for repair and getting told its a software error would be rather embarrassing...
Maybe I missed something, a certain extra driver youre supposed to install, chipset driver maybe, tried searching for something similiar but really didnt get any hits.

When I write CPU intensive, its Maya Rendering, Youtube HD watching etc that triggers the downclocking/throttling.
ATM i'm creating an image of the HDD so I can install SL and see if the issues also persist within OSx

Hopefully you have some ideas I can test out/drivers to install. Else the MB runs flawlessly, except when I try to use its raw power for something other than writing this wall of text in notepad

Cheers
Sunksat (Yup, not my real name hehe)

 

What happens with XP or Vista?

I had a Dell Vista laptop and it had a 5.5 hour battery life but Vista was a pig - operating system and applications were slow. Upgraded to Windows 7 and everything runs faster now but battery life is down to about 2.5 hours. Some have said that it might be that I need new drivers, that there's a battery big in Windows 7. Personally I think that performance for battery life is a reasonable tradeoff.

I also find that battery time on Mac OS X is much better than Windows XP on my MacBook Pro.

 

I havent had neither XP nor Vista installed on it yet. Just ran the Apple Diagnostics CD, found no errors, gonna install SL tomorrow and see how that goes.
Batt time is way better on OSX than in Windows, from a non "I have measured something" perspective hehe. Had to switch to Windows due to incompatibilities with my old win machines. Any other ideas?

 

I generally prefer to run very high-performance applications on desktops (I have two Core i7 systems). I can do video editing on my MacBook Pro and it does get hot but it runs just fine and the fans run at low speed. I have XP on Boot Camp on the machine to run some Windows apps that I need to run but that is fortunately seldom.

 

That CPU is a bit hot for the MacBook pro, you should try to use a program to manually adjustment the fans, set them to kick in at full once temps get past 70 or 80. 100 or more is nearing death zone for a core 2, which is why windows is throttling it so much. Also set the power profile to high preformance, so windows will up fan speed rather than throttle down.

 

if you are willing, go ahead and do a clean installation of snow leopard. then run software update until you have all the updates.

then see if the problems persist. if they do, it's a hardware problem, and you should send your laptop in. i wouldn't be surprised if it went away.

 

Thanks for the reply's and ideas, Windows Power Profile was set to "Balanced" which is the only one in 7 besides "Power Saver".
I just reinstalled Snow Leopard, did all the updates, but the problem is still there. In OSX the cores at full CPU usage sit around 100-102degrees, the downclocking still happens, only difference is it goes straight from 3.06->1.596Ghz. Though in OSX the clockspeed returns to 3.06Ghz rather quickly but ofc goes back to 1.596Ghz shortly after to cool the machine.
The fans sit still at 2000rpm no matter what the temperature of the CPU is.
Spoke with Apple Care again, they had no idea what was going on, so I'm of to an Apple Retailer here in CPH tomorrow to showcase this strange behavior -this was endorsed by Apple Care since they had no idea hehe, funky.

Last note, installed SMC fan control to check if I could tinker with something, made the fans run @6000RPM (which was very audible), but that still didn't make the cores go down in temperature, downclocking still occurred and the temperature kept hovering around 100degrees.

I do the same "mmoy", keep a nice tower for the heavy stuff and the laptop for less intensive things, though at campus I need to max the power from time to time

 

The Apple techs probably asked you this, but have you tried SMC and PRAM resets?

 

Yeah I tried both options, neither helped.
On my way to pick up the machine, apparently they changed the motherboard, hopefully that fixed it. Must test when I get back!
Thanks for all your suggestions
Cheers

 

t9900.... say woooot 100 Celsius. Did you install it yourself? Did you apply ac5?

 

The T9900 is factory installed, haven't touched anything of the innards in this machine. Stupid to say the least that you can't service it yourself :S
Anyway, picked up the machine, on the repair slip they list as having exchanged the motherboard although the technician notes that he could not replicate the error I originally had...Great!
The machine still suffers from the same heat/downclocking...
Not as severe regarding CPU speed as before, but still, now im getting picky:
Cold start->CPU@44Degrees
Start mprime, torture test, 2 cores
The CPU goes to 3.06GHz as it should in no time, temperatures raise
Then the cycle happens:
3.06GHz(100Degrees)->2.926GHz(89Degrees)->3.06GHz(91Degrees)->2.660GHz(85Degrees)->2.926GHz(89Degrees)
Thats the first and only time I see the CPU reach 3.06GHz, the rest of the time it sits still at 2.926GHz (cycling down to 2.660 and back to 2.926)
Thats the cycle it repeats over and over and over, CPU usage never goes below 100% utilization...
Important to note, I use mprime for this particular test, but as stated in the OP this also happens with YouTube HD/Maya Rendering, practically anything that uses the CPU 100%...

Now, the repair shop does not want to see the MAC again, since their technician was not able to replicate my errors, between the lines they implied it was something I did, which I now ask, am I being to picky here?
I mean, you buy the 3.06GHz CPU, then I assume its OK to expect it to be able to run at the specified speed all the time, correct?

I have added a link to a screenshot of the desktop in SL when I run this software, from there you can clearly see excessive temperatures+clocking of the CPU
http://yfrog.com/5nscreenshot20100224at937p
Last addition, its a clean install, fully updated. Only software on the machine is the temp monitoring programs+mprime

Anyone have further ideas of what I should do now? Kinda at a loss...

BTW: Would prefer todo all this in Windows, but if I contact Apple Care with my problem they blame everything on the Windows Installation...

 

Windows has always seemed to run hotter than OS X on MacBook Pros, in my experience.

Is this the same 3.06GHz CPU that apple sells in their laptops, or does it have more cache or something that might make it run hotter?

Apple treats the body as part of the heat sink, for kicks, point a fan at the laptop for see if cooling the body also lowers the heat and kills the throttling.

And thermal paste could make a huge difference. I had to install/reseat my desktop i7 920 CPU three times before I finally got one that ran cool.

 

Apple did not think too well on those machines, the CPU is way too hot for the design, I have the same unit and the ONLY way I could get it to stay cool was to lap the CPU, apply Diamond heatsink compound AND Drill holes in the baseplate below the fan intakes !!!

 

My suggestion is to get a laptop cooler. I have the zalman nc-2000, its quiet and will keep the bottom of your mb cool. Heat issues seem to be common on high performance laptops these days.