Thinkpads Forum

Eh, does anyone know what the average acceptable idle\load GPU temps are for the 14" t60p with the firegl v5250?

I'm running consistently 75-80C idle depending on temperature, and up to 110 (when the gpu finnally gives up and bluescreens) under heavy load. Even for a laptop, this seems really hot.

I had to replace the main fan\heatsink assembly a month back or so, as the other one stopped moving air entirely (fan would rev up extremely high, but no air was moving... guessed that the motor was spinning inside the fan but the fan wasnt really moving). I dont have any heat data from before then, as I only discovered tpfancontrol in my investigation of that problem.

Anyway, any advice would be appreicated - I can't afford to buy a new laptop (or desktop, this is my only machine), and this heat issue really worries me.

Heat was a known issue with the T60p and 110c is too hot! However, several people have reported that swapping aout the fan and cleaning the dust from the internals helped significantly. Are you sure you got the correct fan assembly? Did you use the correct heat transfer methodology for the CPU and GPU when you installed it (pads, grease, or whatever Lenovo specify)? Is it still under warranty?

The cooling was redesigned for the T61p and this is no longer a major issue (there are other issues with the T61p).

Good luck!

The heatsink assembly I replaced the original with was identical to the original, so, fairly certain it was the correct one. I applied thermal paste to both the cpu and gpu heatsink blocks, as I would with a desktop computer. I'm about to go back in there and check out the status of dust, and maybe put a new coat of thermal paste on there...

Were both heatsink blocks copper or did either of them have a grey "heat pad" on them?

The gpu block has a grey thermal pad... but it seems to be damaged. What would I be looking for, exactly, to obtain a replacement for this?

http://img140.imageshack.us/img140/7775/1000295wy2.jpg

there is a picture of it.

That could be the problem. Did you put thermal paste on top of the heat pad? That's probably not a good idea. And the heatpad as it stands may not be making good contact with the GPU. I'd call Lenovo Tech support and ask their advice as I don't really know much about the T60 heatsink setup

Lenovo tech support wont even talk to me, as I'm out of warranty.

Anyway, yea, cleaned up the heatsink assembly and got some AS5 instead of the cheap crap that was on there before... hell of a difference, idling at 70C now.

enneract wrote:Lenovo tech support wont even talk to me, as I'm out of warranty.

Hmmmm, that's a shame - they won't even help you locate a part number for the replacement heat pad?

enneract wrote:Anyway, yea, cleaned up the heatsink assembly and got some AS5 instead of the cheap crap that was on there before... hell of a difference, idling at 70C now.

So you removed the heat pad and just used Arctic Silver or you put the AS on the heat pad?

What's the GPU temp under full load now?

I took off the keyboard and cleaned the CPU fan assembly with a vacuum cleaner a few months ago. The top temperature (idle) dropped by 10 degrees!

I will do that again every few months. Forget the Arctic Silver if you are as lazy as I am.

Currently the top temperature (GPU) of my T60/p is arround 65 when idling and 67-69 with general use.

sktn77a wrote:

enneract wrote:Lenovo tech support wont even talk to me, as I'm out of warranty.

Hmmmm, that's a shame - they won't even help you locate a part number for the replacement heat pad?

Oh, they'd probably point me at the part number for the heatsink assembly - but I'm guessing that I probably couldn't afford it at the moment (uni student), given the price of other parts I've looked at.

sktn77a wrote:

enneract wrote:Anyway, yea, cleaned up the heatsink assembly and got some AS5 instead of the cheap crap that was on there before... hell of a difference, idling at 70C now.

So you removed the heat pad and just used Arctic Silver or you put the AS on the heat pad?

What's the GPU temp under full load now?

I put a small quantity of AS5 on the heat pad. GPU can still be pushed up over reasonable operating temps, but under extreme loads only (for instance, I got it to 107 running crysis)

Well, that's better but still too high! Hopefully, someone else may have a suggetsion to get that idle down into the 60s and the full load down into the low 90s.

So, about the thermal pad on the heat sink. Is it actually a pad of woven material impregnated with thermal grease, or is it just a patch of thermal interface material? I will be receiving my T60p today, and want to go through and clean out the fan & stuff since it is a used unit. I have access to an array of thermal greases & some TIM sheet material at work, but I don't want to go messing with this if it is some sort of thick gap-filling pad. Does the pad fill a large physical gap between the heat sink & dies, or is it just the usual stuff that fills the micro-pores in the surfaces and essentially leaves the heat sink against the die?

Thanks!

It fills a pretty substantial gap, I think.

If I read your other post right, you are an engineer in a related industry? If you do happen to take that apart and give it a look, I'd love to have your input on if removing the AS5 I stuck on the pad would be worthwhile.

Yes, the thermal pads are usually about 1/16" thick - way too thick to fill with thermal grease. Some people have substituted a copper pad of comparable thickness and used thermal grease but it sounds a bit of a kludge to me (?) Not sure what the alternative is, though.

enneract wrote:It fills a pretty substantial gap, I think.

If I read your other post right, you are an engineer in a related industry? If you do happen to take that apart and give it a look, I'd love to have your input on if removing the AS5 I stuck on the pad would be worthwhile.

Yeah, the pad looked pretty thick. However, I cannot imagine that they would design it to stay that way. Usually it is a pad of unbound material that squishes out, leaving only the thinnest possible layer between the die & heat sink. The sheet-TIM one product that I work with uses comes in a 0.1mm thick sheet, but after heating & settling, leaves a ~10um thick bond-line. The thinner the bond-line, the better the conduction.

So yes, I do work in a related industry. My first 2 jobs were as a thermal engineer in the electronics industry, and although I do more general mechanical engineering now, I still do a lot of thermals. I must say that I cannot imagine that they would design the heat sink to leave a gap more than 0.1mm wide, that would be ridiculous.

I plan to take this apart. When it happens, I will document it & share. Hopefully it won't bite me in the rear.

sktn77a wrote:Yes, the thermal pads are usually about 1/16" thick - way too thick to fill with thermal grease. Some people have substituted a copper pad of comparable thickness and used thermal grease but it sounds a bit of a kludge to me (?) Not sure what the alternative is, though.

That is interesting. I am still in disbelief that any competent thermal designer would leave a gap like that & fill it with TIM. Well, I mean if it was only like a 15W chip or something, then maybe it is OK. I cannot find a power number for the V5200 though. Oh well, I can just machine up a copper slug to fill the gap if need-be.

bmwman91 wrote:

enneract wrote: I plan to take this apart. When it happens, I will document it & share. Hopefully it won't bite me in the rear.

Please do this. I am about to have to replace my fan because it is making a constant buzzing sound. I would like to do some of the "fix the GPU heat issue" stuff while I have it taken apart...

Osaka wrote:Please do this. I am about to have to replace my fan because it is making a constant buzzing sound. I would like to do some of the "fix the GPU heat issue" stuff while I have it taken apart...

Well, it might be a little longer than anticipated. I got my T60p today, and the screen has a bunch of little black dead-pixel spots. It has 2 months left on the warranty, so a box is headed my way from Lenovo as of this evening. I am debating paying to extend the warranty, too which might making cracking this baby open a bad idea. We'll see....

bmwman91 wrote:That is interesting. I am still in disbelief that any competent thermal designer would leave a gap like that & fill it with TIM. Well, I mean if it was only like a 15W chip or something, then maybe it is OK. I cannot find a power number for the V5200 though. Oh well, I can just machine up a copper slug to fill the gap if need-be.

A little OT but would you be interested in creating more than one copper slug and selling them to tihnkpad forum members? Also there is a fairly substantial gap between the northbridge and heatsink as well.

There is another post in this forum with the specifications on the gap. I believe one gap is 4mm and the other is 1mm?

Yeah, I had the heat sink off for a repair to the magnesium frame last week. There are definitely some thick pads in there. I am thinking of pulling it again & measuring the pad thickness, and then getting some corresponding copper sheet. From what I have read, the T60p GPU gets really hot (I would not quite say that it has "issues" yet). I work with similar consumer electronics products, and I know that with the standard materials out there, thermal cycling like the T60p GPU sees WILL lead to failures in the die's solder-balls.

Docked and with light usage (Winamp & Firefox), tpfancontrol is reporting a 73C GPU (ambient is ~25C). Under load it has reached 98C. This is NOT good in my book. So, when I get around to taking some measurements, I will post about the right thickness of copper sheet to use and such.

OK, so I did a little modding today. I took the heat sink off, and based upon my measurements, there is ~0.5mm between the GPU die and heat sink surface, which the pad fills. So, I removed the pad, bent the heat pipe a little, bent the prongs on the retaining clip to apply more pressure & applied some thermal grease to the heat sink. I had to fiddle with it a bit installing & removing it to make sure I was getting coverage of the whole GPU die. So, all I really did was (carefully) bend the heat pipe so that I could remove the thermal gap pad, put some G751 thermal paste on it and bend the prongs on the retaining clip to apply more pressure.

The results:

Well, last night I was running MilkDrop from Winamp (pretty GPU intensive at higher settings). The room was probably ~21C, and under sustained load, the GPU was hitting 98C with the fan BIOS-controlled at 3500RPM. It would idle at ~70C with the fan being pushed at 3500RPM by the BIOS as well.

Today, after the mods, I am still idling at 63C, BUT the BIOS has the fan cranking at 3000RPM. Running Milkdrop with the same settings for ~10 minutes, the GPU topped out at 77C. The lab I am doing this in is 23-25C. Now, at home I was docked, which I hear hurts thermals. In the lab, I am undocked.

Still though, this seems to have made a 20C improvement, and has certainly improved my peace of mind. If you plan to do this, you will need to install/remove the heat sink a bunch of times. This is to make sure that the thing is sitting flat on the GPU. You will need a lot of grease. Apply it to the heat sink, install & screw it & its bracket down, then remove it and see how much coverage you have on the GPU. When it is cocked / not co-planar, it will be obvious. You will need to tinker with bending the heat pipe & spring clip prongs. Leave the gap pad on for the Northbridge. I have no idea how hot it gets (or doesn't), but there is NO good way to bend the heat sink to sit flat on that AND the GPU...unless you have a precision mini sheet-metal-break. Is there a thermal diode in the NB that TPFancontrol reads? If so, I am not worried about it because nothing else in the laptop reads over 50C.

Also, I bent the heat pipe enough that the satellite heat sink for the GPU/NB was sitting 2-3mm lower than before. Do NOT glue the heat pipe to the CPU portion of the heat sink. You will need it free to move so that it will not be messing up the CPU portion's co-planarity. I saw the DIY on here for using thermal epoxy on the heat pipe, and I don't prefer that method myself. Yes, the CPU has plenty of head-room as far as thermals, but I would not recommend dumping extra heat there if it is uneccessary. Second, there is the whole heat sink seating issue. Since this system has 3 individual dies, each of different height & location, the heat sink NEEDS to be physically flexible enough to mate to each one properly. The gap pads are good in that they are very forgiving of physical misalignments (a big one in this case would be 10 mils)...grease demands great mating accuracy.

Now, I could see using the thermal epoxy on the gap while it is all installed on the laptop & properly seated (I would recommend running the laptop for a couple weeks to let the grease seat completely & all the excess to squeeze out). Do that at your own risk, though. The CPU probably would be fine (not sure about that if one upgrades from CD to C2D though). Anyway, that's my lengthy post.

[apologies if I am post-whoring]

I have noticed that the fan is OFF a lot when idling lol. The GPU is cooled so much more efficiently that tpfancontrol (and my ears) report that the BIOS has turned the fan OFF a lot of the time, and the GPU is typically 62-66C in a ~23C room. As I type, the fan is running at 3018RPM, the GPU is 59C, and the laptop is on my lap (which usually heats things up a bit more). Booya. The G751 thermal paste has a ~3 day burn-in period form what I have observed in reliability tests at work, and other tests from people on the web...most people with a proper installation see a 5-10C drop in component temperatures after 3 days of frequent usage.

The only downside to G751 is that it is generally only available online, and a tad pricey (the 2 fl-Oz tubes at work are $110US). Well, that and it is a royal PITA to apply as it does not stick to the working surface well, and you need a credit card or small spatula to apply it...and it takes practice to get a thin layer. You MUST apply a thin layer, a thick one will not squeeze out the excess & work properly. Practice practice practice.....

TPFanControl shot...web browsing, computer on my lap, 23C room.
http://www.e30tuner.com/other/tptemps/T ... 009_01.png

I still plan to go a little more bonkers with the heat sink. We have lots of junk heat sinks at work with copper fins...I am thinking of removing them from their bases (they are soldered on), trimming them to be the same height as the heat pipes and soldering them onto the copper bases (top side) of the TP heat sink. I will probably also fill the gap under the GPU heat pipe with thermal epoxy so that it dumps a little heat into the CPU portion of the assembly.


Warning: Random information about thermal performance & chip lifespan to kill time before I go see a movie with the GF
The reason for all of this is longevity. T60p's are NOT getting any easier to come by, and the IPS display equipped ones will always be in demand. From on-going reliability tests of the product I work with, which has a CPU & GPU, there is a definite relationship between the number of thermal cycles and peak chip temperature. Obviously, as peak temp decreases, the number of cycles to failure increases. It is not liner either...it is more of an exponential, or "hockey stick" relationship.

Below a certain threshold, changes in peak temp make little difference in longevity. However, once you cross the threshold, a few degrees change in peak temp can drastically reduce (or increase) the component's life. The mode of failure that will typically be seen with flip-chips such as these is cracking in the solder bumps connecting the silicon die to the small PCB underneath (called the substrate). The gray epoxy stuff you may have noticed around the edges (called the under-fill) has a lot to do with it as well. There is a temperature (glass-transition temperature) where it softens, losing its mechanical strength, and thus all the mechanical stresses are placed on the solder joints of the chip. As you know, materials expand when heated...and different materials do so at different rates. The silicon die expands a different amount than the substrate, and this mismatch in strains induces stress in the under-fill & solder bumps. You want to keep it all below the under-fill's glass transition temperature so that it will bear the stress as much as possible. Lead does not fatigue well lol.

This cost my company over US$1B a couple years ago, Apple & nVidia are getting hit by this problem right now (cost cutting often leads to this as it can cost a lot more $$$ to properly design high performance silicon systems), and ATI has had its share of issues. I am fairly sure that some of the T4x laptops have succumbed to this too.

Additional reference on flip-chips:
http://en.wikipedia.org/wiki/Flip_chip