MacBook Pro 2011 17" hard freeze

A couple of observations from testing it under bootcamp;

EDIT: Retracting previous observations, the program I was using was displaying incorrect data. Turbo boost working as intended.

Message was edited by: lithast

I tried it and you're right. Using the integrated graphic chip, everything works perfect. Rendering, benchmark. Hmm, so maybe a problem a firmware update could solve? Or should I sent it back? Maybe there is a chance to get a new and working one? What do you think?

It's always been known to me that a super conductive thermal paste like arctic silver for example will result in too much heat being retained in the CPU.

Energy flows from regions of high temperature to low temperature. If you stick thermal paste on a cpu that is generating heat, the thermal paste isn't going to suck up the heat and not release it if there is a heat sink sitting on the other side of the thermal paste that is cooler. One would expect the heat sink to be cooler because it is going to have a side with fins (to increase the surface area) that is exposed to the air. The only way heat is not going to flow from the cpu -> thermal paste -> heat sink -> air is if the air is at the same or greater temperature as the heat sink. This is basically the second law of thermodynamics.

John, I just assumed that metal-to-metal contact was an inherently more efficient way to transfer heat...

In theory metal to metal is good because metal is generally a good conductor of heat. If this was sufficient then no thermal paste would be used at all. However, you cannot make two pieces of metal perfectly smooth. No matter how hard you try you'll have a small gap between the two. +Note this is the same principle of double pane windows in a house where you want a gap of stagnant air to prevent heat from leaving in the winter and entering in the summer+. When the thermal paste is applied most heat sinks are then placed on top of the cpu and some form of pressure is used to hold them on. The thermal paste normally isn't viscous enough to provide resistance and hold the two pieces of metal apart (cpu and heat sink). So basically the thermal past just fills in the gaps.

The pressure of the heat sink will force any excess thermal paste out along the edges. It is possible that this can squirt out the side and then somehow get on top of the heat sink (this is the only case were I can see it causing problems) and prevent heat from leaving due to convective heat transfer along the surface -- it fills in the fins on the surface, reducing the surface area and the rate of heat transfer to the air. We're talking a huge amount of excess here and it would probably end up slathered all along the inside of the laptop as well.

Alright John, I'll respectfully disagree on that. It's just a known quantity in the computer assembly process that you do not use excess thermal paste. It was the same issue apple had with their 1st gen MacBook. It's what we in the repair business know 1st hand, i'm not particularly knowledgeable about the exact mechanism, but it's fact. A very thin film of thermal paste is the required amount. Not a slightly thicker one, and these are very minute differences. Couple that with a very high horsepower processor and the same cooling system from a CPU that was 10W (35 vs 45) less power hungry and you have problems.

Another thought I had was whether they may have had a bad batch of thermal paste. This would have affected a very large swath of machines (as is evidenced here).

Message was edited by: Chullo

I suppose we will have to agree to disagree on this one. I didn't want you focusing on something that was inconsequential while trying to debug this problem.

By the way, as an undergrad I worked as a computer technician doing computer assembly and repair 🙂

I tried everything I did before, like Video rendering under iMovie and Premiere CS5 - no crash with integrated card on. I also did the smalluxgpu Test with cpu*8+GPU and 800x600 resolution. With ATI Card on, the System freeze after a 10 seconds on 91 C°. With Intel Graphic I've stopped the test after 300 seconds. Temp between 89 and 94 C°.

Temp idle with safari on and integrated card: 50 C°

Message was edited by: rockngroll

John ----- Nice. Doing it now as a natural talent while I do my masters. What do you think of my last thought? ....whether it may have been a bad batch of thermal paste?

Message was edited by: Chullo

Rockngroll --- you my friend are in the same boat as most of us here....heating issue probably combined with some other driver/firmware problem. The point is, the issue reproduces itself when our temps go up and approach 100C.

John, I understand that thermal paste basically "fills in the gaps" between the metal-to-metal CPU-to-heat sink contact. My assumption is that if too much thermal paste is applied, not all of it would "squirt" out when the heatsink is clamped to the CPU and consequently very little, if any, metal-to-metal contact would remain.

I will tell you that in enthusiast computing circles it's recommended that the minimum effective amount of thermal paste be used. In my personal experience building gaming PCs, there's not very much clamping force between the heat sink and the CPU. Since thermal paste is pretty viscous, it's feasible that too much thermal paste could inhibit metal-to-metal contact between the CPU and the heatsink simply because the excess paste wouldn't "squirt" out the side.

In my opinion it's inaccurate to assume that all excess thermal paste, regardless of how much is initially applied, will "squirt out" once the CPU and heat sink are clamped together. If you use too much paste, some will remain in the CPU-heatsink gap, effectively reducing heat conductivity by reducing the metal-to-metal contact area.

Since we're throwing around academic credentials, I'll mention that I have an MS in aerospace engineering with a focus in computational fluid dynamics, so I know a little about fluid viscosity and the like. 🙂

If for whatever reason the bad batch had a low thermal conductivity (pretty much its most relevant property) then that would make sense. I suppose it could have a very low viscosity at high temperatures as well. If they got a bad batch then they should sue the **** out of the folks.

Yeah I pretty much did the same thing in school: Flexible hours, decent pay, and lot's of problem solving opportunities.

Schwa72 -- Well said. To the matter @ hand. I just ran the smalluxgpu @ 1024x768 @ 8 cores but only on the integrated graphics and the CPU temp tops out @ 92C Witt the fans blaring @ 6200. No hangs at the moment. So maybe only the ATI chip has an issue? I do know that both the processor and the GPU are connected via the same pipe so maybe it is the GPU overheating? The combination of both?

Second thought....it could still be a driver issue as any catastrophic error in the driver is exacerbated by stressing the GPU with calculations. Making the heat just a symptom that would be present regardless.

Message was edited by: Chullo

Sorry Schwa my intention wasn't to throw around academic credentials. I was simply trying to point out that I wasn't just shooting my mouth off. I've seen a lot of mention of thermal paste being a problem with these computers and a one off remark from the iFixit link is the only thing I've seen anyone reference. I just don't want people to go too far astray when trying to understand the problem.

In my experience building and working on computers there has always been ample pressure to force out excess thermal paste. Of course your experiences may differ from my own.

Something Im puzzled about - a bunch of you are quoting 6200 RPM as the max fan speed. What tool are you using for this as my fans seem to max out at 5500 according to smcFanControl?

This is with a MBP 17 / 2.3GHz (that aslo freezes when it gets hot and GPU is in use).

Chullo - I'm unable to run SmallLuxGPU in integrated only mode on my machines with GFXCardStatus - it immediately terminates when I initiate the test. I can run in Discreet and Dynamic Switching modes and produce failures on all three machines. Thoughts?

John- No worries. Who really knows how much of an issue the thermal paste is in the case of these Macs. I did understand you were simply trying to qualify your comments by mentioning your PhD; I was just being an ***. 😉

Chullo- I'm confused. When I ran the smallluxGPU test, I left Automatic Graphics Switching engaged and didn't have any problems. I assume that the ATI GPU was getting taxed in this case...weren't you also able to successfully run the test with automatic graphics switching enabled? I just figured that if my ATI card didn't crash, the integrated GPU would work fine also.

Oops, never mind, that was Adrian J. who was able to successfully complete the test, not you. My bad.

Message was edited by: Schwa72