Where is the heat?

[tatekuhic]

For the bulk of my folding, I used a Dell laptop with a Core2Duo processor, rated at 2.4 ghz. When this computer folds, it gets up to 90 C easily unless it is wintertime when part of my apartment is not heated. After it hits 90 C the CPU downclocks, first to 1.5 ghz, and then down to 0.8 ghz. This allows folding to continue albeit at a much slower rate. My MacBook Pro (with exact same CPU as my Dell), which I dont normally fold with, but tested it once, gets as hot as 110 C. It never downclocks so I shut it down manually then. That's just too hot for the long term.

Recently I got a new Dell laptop, running an i3 processor at 1.8 ghz. This computer is VERY surprising in that there is relatively NO heat given off during folding. Nor does it downclock. It ALWAYS runs flat out at 1.8 ghz. The temps max out at 60 C and this is *without* any major spool up of the fans. The laptop is as quiet as you can imagine. My other Dell would have the fan going full power, making all kinds of noise.

I'm amazed at how quiet and cool folding with this laptop it. It is a very cheap Dell laptop, nothing special. It cost at most $600.

Where is the heat when running 100%? How can I fold so much better (I get more PPD with this computer) and not generate so much heat?

Are i5's and i7's this cool too?

[gunnarre]

Most likely this is due to advances in process node technology (the same transistors can be made more densely on the silicon, with less power dissipation) and architecture improvements (the same calculations can be done in a more efficient manner by using less transistor state changes to do the same job). CPUs with SSE fold better than CPUs without, and CPUs with AVX and AVX_2 support fold even faster than CPUs with only SSE support.

If you post the exact models of CPUs you're talking about we might be able to explain it more thoroughly by looking at the available features and expected thermal performance.

The cooling design of the laptop might also help explain some of this - if the old laptop has dried up cooling pads and dust-clogged fans, it would further reduce the efficiency over time. If the new laptop has a better cooling design, it would also allow the CPU to keep folding faster.

The power settings in the laptop - BIOS or Windows/Linux kernel - might also have something to do with this. Your laptop could possibly be made to fold even more agressively than it is today, and achieve even higher PPD. If your new CPU has E-cores in it, it might be a good idea to see if you can make two different CPU slots for the E-cores and the P-cores, or just fold on the E-cores to get even better efficiency.

[JimboPalmer]

https://ark.intel.com/content/www/us/en ... 0-ghz.html

This CPU is only new in comparison to a Core Duo, but one of the specs is that it only draws 17 watts.

https://ark.intel.com/content/www/us/en ... z-fsb.html

By comparison this CPU draws 65 watts.

I simply googled i3 1.8 and core Duo 2.4, these are the CPUs that popped up, but are not necessarily your CPUs. We have no facts to determine that.

[toTOW]

Since the Core 2 Duo laptop is a very old one, it might be a good idea to clean air vents and heat sinks from dust ... it might be a good idea to replace the thermal paste between CPU and heat sink too ...

[rkv_2401]

I used to have a machine with a Core 2 Duo T7200 @ 2.0Ghz. It would overheat and turn it's fans up to jet speed even when playing a side-scroller game, and it's iGPU would overheat and BSOD on running the Windows Energy screensaver for more than half an hour. You probably have a Core 2 Duo P8600 in your old laptop(https://ark.intel.com/content/www/us/en ... z-fsb.html) with a 25W TDP, which is slightly lower than the 34W TDP of my T7200, but your new laptop probably has an ultra-low voltage chip with a 15/17W TDP it'll never touch (i3s don't have turbo boost and the i5/i7 models usually have the same 15/17W TDP and also have to boost higher).
Not to mention, cooling mechanisms for laptops back then were archaic and often an overlooked aspect of their design.

Dust is also a very real concern - my 12 year old Inspiron with an i5-430M had a really good cooling system back in the day but now I have to run it at 1.33Ghz to keep it from cooking itself, even at desktop idle.

[RolandK]

why are the links in the posts broken? there is missing some in between ( en ... z-fsb.html )

[Joe_H]

why are the links in the posts broken? there is missing some in between ( en ... z-fsb.html )

See this notice - viewtopic.php?t=37843. The links did not get completely preserved when the forum contents were moved to an updated forum software on a new host.

[RolandK]

but my link is broken just after posting

[Joe_H]

Which link was broken right after posting? The previous links in this topic date to January, the move to a new host and version of the software was in April.

[RolandK]

oh , sorry, you are right. that was my fault then. thanks for pointing it out