By: Gian-Carlo Pascutto (gcp.delete@this.sjeng.org), August 14, 2019 12:43 am
Room: Moderated Discussions
David Hess (davidwhess.delete@this.gmail.com) on August 13, 2019 1:51 pm wrote:
> I cannot say that I have ever had that problem but for good reason. Operation of the CPU at the
> thermal throttling temperature is not conducive to reliable operation so I have never allowed
> it. If the peak temperature is above about 65C Tj, then the heat sink is not large enough.
It's typical in every laptop ever to hit TJmax all the time at load, and modern AMD CPUs will boost till they either nearly hit the thermal limit (95C Tj) or their power limit, the latter of which can be increased with PBO. In this case it's going to be "rather difficult" to stay below 65C without water cooling and radiators. They'll be stable nevertheless.
The heat sink is only part of the equation, it'll easily go over 100C if it doesn't have enough airflow, which requires fans, whom make noise.
The problem with the Gigabyte boards was that they spun up the fan to 100% below the Tjmax of the CPU.
> As far as the noise from the CPU fan, unless it is a small whiny one, its noise should be insignificant even
> at high speed because it is naturally mechanically well isolated from the case which also shields it.
When I said earlier it's easy to build a *somewhat* quiet system but hard to build a *really* quiet one, this is exactly what I had in mind. Even extremely quiet fans like a Noctua will end up being the loudest component if running at anything close to full speed.
If you can't hear your CPU fan at full speed, it just means the rest of your system is loud.
> Even more often, they leave out temperature measurements. As above with CPUs but even
> more so, my experience is that GPUs which operate above 65C Tj have poor reliability.
I absolutely cannot second that observation. Note that most GPU have a fan curve that will put them around 70-80C under full load. If they are not reliable at that point I RMA them because they're broken.
https://images.anandtech.com/graphs/graph14663/111586.png
https://www.guru3d.com/articles_pages/gigabyte_geforce_rtx_2080_gaming_oc_8g_review,9.html
As you can see, the idea that a modern GPU runs below 65C at full load is an illusion.
--
GCP
> I cannot say that I have ever had that problem but for good reason. Operation of the CPU at the
> thermal throttling temperature is not conducive to reliable operation so I have never allowed
> it. If the peak temperature is above about 65C Tj, then the heat sink is not large enough.
It's typical in every laptop ever to hit TJmax all the time at load, and modern AMD CPUs will boost till they either nearly hit the thermal limit (95C Tj) or their power limit, the latter of which can be increased with PBO. In this case it's going to be "rather difficult" to stay below 65C without water cooling and radiators. They'll be stable nevertheless.
The heat sink is only part of the equation, it'll easily go over 100C if it doesn't have enough airflow, which requires fans, whom make noise.
The problem with the Gigabyte boards was that they spun up the fan to 100% below the Tjmax of the CPU.
> As far as the noise from the CPU fan, unless it is a small whiny one, its noise should be insignificant even
> at high speed because it is naturally mechanically well isolated from the case which also shields it.
When I said earlier it's easy to build a *somewhat* quiet system but hard to build a *really* quiet one, this is exactly what I had in mind. Even extremely quiet fans like a Noctua will end up being the loudest component if running at anything close to full speed.
If you can't hear your CPU fan at full speed, it just means the rest of your system is loud.
> Even more often, they leave out temperature measurements. As above with CPUs but even
> more so, my experience is that GPUs which operate above 65C Tj have poor reliability.
I absolutely cannot second that observation. Note that most GPU have a fan curve that will put them around 70-80C under full load. If they are not reliable at that point I RMA them because they're broken.
https://images.anandtech.com/graphs/graph14663/111586.png
https://www.guru3d.com/articles_pages/gigabyte_geforce_rtx_2080_gaming_oc_8g_review,9.html
As you can see, the idea that a modern GPU runs below 65C at full load is an illusion.
--
GCP