MBA Early 2015 - temp too high at 103c?

[rnranimal]

I had a few keys go bad on my 13" MBA 2.2ghz i7 and cleaning didn't help so I bought a used top case and moved everything over to that and that's all good now. However, during this repair I broke the heatsink end where it is screwed down near the fins. The screw was buried and I didn't see it before I started pulling it out. So I bought a used heatsink and some Ceramique 2 paste and replaced it. Fans seemed to be spinning up a lot more so I downloaded a temp app (hadn't really paid any attention to the temps on this machine before, so I have nothing to compare) and saw the temps spiking way up to 80-90 at times where I wasn't doing anything that should cause that. It was very erratic. I had done the small dot of paste method. So I took it back off and put more this time. Probably not as much as was on there from the factory (quite a bit smooshed way out from all edges) but probably some smooshed out. Now the temps are consistent during normal activity. When I stress the CPU (video encoding), it's very quickly jumping to upper 90s and then settles on bouncing between 98-103c and stays there while fans blast at full 6500rpm. Is this normal or should it not be going that high and staying there? During this time the surface of the heatsink is reading 70c with an IR gun. Does that indicate that not enough heat is being transferred to the sink or is that reasonable?

I'm just wondering if this is pretty much as good as it gets or if I should be going down the road of copper shim and better paste.

I have searched the web the best I could for this answer and couldn't find much but wasn't able to get the answers I was looking for. Thanks for any help.

 

[rnranimal]

I decided to try something. I stacked my broken heatsink on top of the installed heatsink. Put paste between them when they would touch (right above chip and along the finned section) and then some paste where the case will touch the stacked heatsink. The case will screw down but is a little stressed in that corner. From what I can see, I don't think there is pressure put on anything other than the installed heatsink but I can't be sure and this is my one concern. It's definitely helping the temps. Takes 5 minutes to reach 100c whereas before it was jumping right to it. Then it didn't go over 100c by 6 minutes. Before, it would've been bouncing between 98-103 for pretty much the whole 6 minutes.

So seems a worthwhile mod if I'm not damaging anything by squeezing it into the case when I screw it down. Any thoughts on that?

 

[Wickintime]

When you had it open, did you clean out the fan assembly? I have opened these up to find a wad of accumulated fluff wedged between the fan assembly and the outlet port. No amount of blowing or vacuuming would shift it until I split the fan assembly (not difficult, just be careful). All well after that!

I use Mac's Fan Control set to monitor CPU temp.

 

[rnranimal]

Yeah, I vacuumed it out and the fan spins freely. It was actually still really clean from when I cleaned it 2 years ago when I replaced the battery.

Right now I'm using iStat for fan control. It's still in the trial period but I may buy it.

 

[Falhófnir]

That does sound a couple of degrees hot, technically the chips operate up to 105C, but they usually throttle to keep to no more than 100C, I guess as an extra safety margin. Operating in the high 90s to 100 under load isn't uncommon at all, that's pretty much what you'd expect, but going over 100 isn't something I've seen before? (granted that's only from watching Youtube tests on new machines!)

 

[rnranimal]

That does sound a couple of degrees hot, technically the chips operate up to 105C, but they usually throttle to keep to no more than 100C, I guess as an extra safety margin. Operating in the high 90s to 100 under load isn't uncommon at all, that's pretty much what you'd expect, but going over 100 isn't something I've seen before? (granted that's only from watching Youtube tests on new machines!)

That's what I was kind of thinking. I've made modifications that have helped a lot, but if I run at 100% long enough, it will creep up to and still over 100c. However, it takes some time to get there and when running at 50% (2 threads), I'm staying under 100c. Previously, 50% would get up over 100c after a minute or so.

As mentioned above, I have taken another heatsink and stacked it on the installed one. Putting paste between them where they touch (right above the CPU and the fins). I bent the lip of the fan casing up some so that it didn't only focus on the installed heatsink but would blow some air a little higher over the stacked heatsink fins. Also, the case touches the stacked heatsink along the fins, so I put paste there as well. I am also using iStat menu to have fans go to 3k when any sensor goes over 40c, 4500 over 65c and full blast 6500 over 80c. The case now gets very hot when the CPU is at highest temps but I have a metal grated stand I keep it on so that's not an issue for me.

Right now, I use CPU Stress Test while watching iStat temps and activity monitor to manually get an idea of temps vs activity and if throttling happens. Are there any free apps to give me a proper testing of how my laptop is doing with temp vs CPU usage?