Prime95 stress test of Macbook 1,1

i have a question for you Mac gurus:

my friend's Macbook (revision 1,1 with a 2.0GHz Core Duo processor) was bought in 2006 and was never cleaned. she was complaining that it overheats very easily and has become very slow. so i decided to open it up, clean it up, and apply new thermal paste. a thick layer of dust (about 6mm thick) came out from between the fan and the heatsink, and the motherboard was covered with dust and cat hair. anyway, i clean it up (the motherboard, the fan, the heatsink) completely with compressed air, took out all the stuck hairs with a pair of tweezers, removed the old baked thermal paste, and applied a thin layer of Arctic Silver 5 on top of the CPU and the Northbridge and put the laptop back together.

after turning it on and ensuring that everything is working just fine (they do!), i ran Prime95 on the laptop overnight for 10hours:30minutes to stress the CPU and break-in the new thermal paste. the maximum temperature was 89C (but mostly stayed at 88C) and the minimum was 77C. it never reached 90C, ever. since the T_junction for this CPU is 100C, i'm assuming these are good temperatures for a 100% stressed CPU in a small laptop, am i right? after 10hours:30minutes period of Prime95, i stopped the workload to let it idle, and it reached 49C and stayed there.

one thing i noticed was that in periods of about 15 seconds, the temperature would drop slowly from 88C down to 79C and then would go back up again to 87C or 88C, and it would repeat this over and over. is this a sign of the CPU throttling? i could not find any utility that shows the real-time CPU clock speed on Macs, so i had no idea if it's indeed throttling or not, but Prime95 was doing its work at about the same speed all the time, maybe about 0.002seconds difference for every 10000 iteration. what do you guys think this is?

any help is much appreciated

 

Try throttlestop to monitor and tweak the CPU

It can also mean that the fan is kicking in

 

thanks for the reply. but i though Throttlestop is Windows-only. is there a Mac version as well?

 

No unfortunately, cpu monitoring is disabled on OS X from what I know

What you can do though is set a custom fan profile with SMC Fan control, rev the fan up earlier to reduce overheat. You can even set it to autostart everytime you enter OS X

 

well, i think the laptop is doing fine managing its own fan speeds right now. i mean, a Core Duo CPU (6-years old tech) working both cores 100% at 2GHz and being stable at 88C seems just fine to me.

i was just asking to see if you guys also think 100% CPU @ 88C and idle @ 49C sounds fine as well or not.

 

My i5-2515E manages the low 55's on idle, but goes to 89 on Folding@Home.

It's normal, there's nothing to worry about

 

great. thank you very much.

 

i think Coolbook should support that Mac (cpu tweaking utility) have a look:
Coolbook

 

I wouldn't trust apps that tweak CPU and system, on a mac.

Moreover if it's not free

 

I haven't looked at Coolbook in a few years,but found it reported lower temps than other software, which would be nice if it wasn't reporting the different temps at the same exact time.