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Custom Fan to Reduce Throttling

GreyFox7

Super Moderator
Staff member
Am I reading it right. 90° and 44% throttling?
That 44% number is very misleading. What you want to know, I can't tell from this, is what percentage of maximum performance you get. it appears that natively it was running at 86% of max in sustained use after it achieved stabilization. (it spikes up quickly, drops back quickly then ramps up slightly to its stabilization point where it runs for as long as I ran it). That was with 100% Power Limit Throttling and No Thermal Throttling.
 

Knuck

Member
That 44% number is very misleading. What you want to know, I can't tell from this, is what percentage of maximum performance you get. it appears that natively it was running at 86% of max in sustained use after it achieved stabilization. (it spikes up quickly, drops back quickly then ramps up slightly to its stabilization point where it runs for as long as I ran it). That was with 100% Power Limit Throttling and No Thermal Throttling.

It's the 90° I would be worried about if it's for any sustained time.
 

GreyFox7

Super Moderator
Staff member
It's the 90° I would be worried about if it's for any sustained time.
My Lenovo X1 that I've had for a few years now and is a very good laptop... runs at 97c when its stressed and throttling. I always knew it was hot but had never looked at it in detail until recently with all the noise about SP3 Throttling.

My MBA also runs hot and fan runs much louder but it doesn't support running XTU so I don't know specifics yet about what's happening inside.
 

Knuck

Member
The form factor of the surface is much different from the standard laptop. I would think that a CPU running at 90°in the Surface would have a significantly greater detrimental effect on the overall heat of the motherboard etc. given how thin it is compared to the same heat in a larger enclosure.
 

GreyFox7

Super Moderator
Staff member
The form factor of the surface is much different from the standard laptop. I would think that a CPU running at 90°in the Surface would have a significantly greater detrimental effect on the overall heat of the motherboard etc. given how thin it is compared to the same heat in a larger enclosure.
I suppose we can second guess the engineers until a bull gives milk but its capable of more aggressive limiting. Unless Cothek has disabled something it should be fine. Regardless, if you augment your device with a fan and don't tinker otherwise then all other system protections should still be in play. I don't see a problem.
 
OP
Cothek

Cothek

Active Member
The form factor of the surface is much different from the standard laptop. I would think that a CPU running at 90°in the Surface would have a significantly greater detrimental effect on the overall heat of the motherboard etc. given how thin it is compared to the same heat in a larger enclosure.

Most boards and their components are made to withstand this high of a temp and should not be a problem (keep in mind that 90C is die temp and not surrounding components). The throttling problems the SP3 was having was due to an external (to the proc) temp reaching some value (that we don't know) and then telling the CPU to power limit. My fan actually keeps these components cooler and therefore the power limit throttling never fully kicks in.
 

GreyFox7

Super Moderator
Staff member
Another way of showing what the effects of this are is showing the differences in CPU/GPU TDP.

A test without and with the fan should show an increased TDP reading with the fan.

A test without and with the fan showing CPU/GPU Frequencies with sufficient load to demonstrate impairment and less impairment.

Both are viable... I can't tell from the posts what the gain is although I'm not doubting it in the slightest.
 
OP
Cothek

Cothek

Active Member
Another way of showing what the effects of this are is showing the differences in CPU/GPU TDP.

A test without and with the fan should show an increased TDP reading with the fan.

A test without and with the fan showing CPU/GPU Frequencies with sufficient load to demonstrate impairment and less impairment.

Both are viable... I can't tell from the posts what the gain is although I'm not doubting it in the slightest.

I didn't post any of those details because I didn't want to bore everyone but if you guys want to see them, I am happy to oblige.

A few caveats, these tests were done at my work where the building is kept at a nice 72F and I sit right under the AC which if I run the test at home where I keep the temp at a much more cost effective 77F the results are different, so your mileage will definitely vary. At work running the CPU test (without the fan) gives a minimum frequency of around 2GHz while at home it drops all the way to .8GHz which is what most people will see. I'm not at home so I can't run the tests now but perhaps later. For now, here are the results from work:

No fan
08-12 Skyrim Balanced.png


Fan
08-12 Skyrim Balanced Old Fan.png


The Total TDP without the fan stays around 11-12 Watts while with the fan it stays around 15-16 Watts. And again, this gap was greater at home where the ambient was higher.
 

GreyFox7

Super Moderator
Staff member
Note: You have to look carefully but in the top graphic Power Limit Throttling is 100% all the way across.

For those not familiar the numbers displayed on the left in the graphics are the values at the point where you see the white vertical line.
 
OP
Cothek

Cothek

Active Member
Note: You have to look carefully but in the top graphic Power Limit Throttling is 100% all the way across.

For those not familiar the numbers displayed on the left in the graphics are the values at the point where you see the white vertical line.

I should also note that the graphs were playing Skyrim.

On a different topic, when I use the fan I have yet to hear the internal fan reach max RPM (even under max load) which effectively reduces the noise level of the unit.
 

Stephan

Member
I should also note that the graphs were playing Skyrim.

On a different topic, when I use the fan I have yet to hear the internal fan reach max RPM (even under max load) which effectively reduces the noise level of the unit.

What fan did you use as your custom fan ?

I can't wait to test this when you'll have finish !
 

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