Author: CPL0
Subject: X99 Taichi Xeon Tjmax
Posted: 18 Feb 2017 at 5:10pm
Tjmax or "temperature target" is a figure to describe the minimum TCC activation temperature. TCC activation occurs when DTS=0 if TCC offset is 0, Tjmax is used as a means to approximate core temperature. Tjmax is used by some softwares to report core temperature by subtracting DTS from the programmed Tjmax value. Therefore changing this value can result in incorrect reporting of core temperature values. Tjmax has nothing to do with the inbuilt catastrophic shut down temperature.
The TCC activation offset is used for lowering activation, not the Tjmax value.
Lower Tjmax = lower reported temperatures and does not change the temperature point at which DTS=0
You've got that back to front. The point is I don't want to alter it, I want to keep the Intel Spec, why has Asrock altered it? One can see the discrepancy when using PECI vs core temp, a 5C difference.
Subject: X99 Taichi Xeon Tjmax
Posted: 18 Feb 2017 at 5:10pm
 Xaltar wrote:Tjmax determines when the CPU will throttle or shut down due to heat as I am sure you know. |
| Xaltar wrote: If ASRock set it lower or higher than intel's default rating it is likely due to testing and study of the CPU's behavior on that particular BIOS version. Coded changes in the BIOS can drastically effect temps and performance, it is not uncommon for manufacturers to allow a cushion or buffer by lowering the Tjmax limit slightly, this goes a long way to protect your CPU from sudden spikes that could shoot the temps over the Tjmax limit and damage the CPU. |
| Xaltar wrote: CPU temp changes have been a lot more abrupt since manufacturing processes have gotten smaller and dies more dense. Where in days of old we would see CPU temps rise say 20c over a few seconds we now see them spike from 30c to 90c almost instantly. The lower than rated Tjmax makes sense in this scenario. |
| Xaltar wrote: Out of curiosity, why would you want to alter the Tjmax setting? It would only be an issue if you are using inadequate cooling. |