Le_Forgeron <jgr### [at] freefr> wrote:
> Le 05/02/2012 16:23, Mike nous fit lire :
> > Hello,
> > 
> > I have an Intel i7 920.
> > It rapidly jumps from 50C to 80C, in full load on Povray 3.7 R3.
> > How could I ask Povray to use less processor?
> > 

> Side note: 50°C to 80°C for an i7 is not the usual range, you have an
> issue in your cooling-fan (my current range for i7 (970 & 980) is 20°C
> to 55°C, and that's because my motherboard setting is limiting that for
> 55°C)

  I agree. If your CPU is running that hot in full load, it's something
you should investigate, rather than simply trying to avoid the problem
by not running any cpu-intensive programs. (Not being able to run such
programs makes your computer less useful than it could be. You shouldn't
have to worry about that.)

  Note that modern CPUs usually are very hard to break even under very
strenuous circumstances because they automatically throttle down if the
temperatures raise too much. Nevertheless, it's still good to find the
source of the problem.

  Older Intel CPUs (such as the Pentium4) ran a bit hot when under full
load (something like 60-70 degrees was about normal with 100% CPU load,
and something like 40 degrees when idle), but AFAIK newer CPUs such as
the i7 should be cooler even under 100% load on all cores. 80 degrees
sounds a bit too much. I don't know what the recommended temperatures are,
but I think it's probably less than 70 degrees (probably significantly
less).

  There are many reasons that could cause this, such as:

- If the room temperature is very hot and humid, it could cause the PC
to overheat. However, a good-quality computer case should take care of
that, which brings us to:

- A cheap, low-quality computer case could have very poor ventilation.
Granted, there aren't many such computer cases made nowadays, but you
never know.

- In some cases wrong BIOS settings can cause the CPU fan to run at the
wrong speed, making the fan either run way faster than needed, or
altnernatively not running fast enough, making the CPU to run very hot.
This is something people are seldom aware of, but can be a real source
of overheating (or fan noise) problems. I have actual personal experience
of this. (In my case it was horrid CPU fan noise, as even a slight raise
in room temperature made it spin way too fast. Normal speed is something
between 2200 and 3000 RPM, but the wrong BIOS settings caused it to speed
up to even 6000 RPM when the room temperature was even slightly high,
completely needlessly.)

- A failing fan is, of course, also a possibility. However, if it's
spinning too slowly, your fan monitor should be showing that.

- It's not completely out of the realm of possibility that your CPU
temperature monitoring program is reporting wrong values. These monitors
need to be calibrated (but I have no idea how this is done, or even how
or if it's supposed to be done by the user).

-- 
                                                          - Warp

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