x399 Taichi + TR1950x high CPU temps @ idle

What monitoring program are you using for temperatures? The on-die temperature sensor (hwinfo64 will call it Tctl) is set to be 27C higher than actual temperature (Tdie is derived from Tctl, removing this offset). The CPU temperature sensor derived from the Nuvoton NCT6779D chip also uses Tctl. This isn't a motherboard thing, or a 1 off thing. AMD set their CPUs to do this on purpose, for the purpose of tuning boost/XFR frequencies and fan speed curves.

parsec wrote: daddyo wrote: X399 Taichi TR1950x Enermax Liqtech TR4 360. I'm just started with this build, and have hit a couple snags. One of them is the 49c idle CPU temp reported in H/W monitor. Motherboard sensor is at 30c, which is about a 8c delta over ambient. That means that the cpu delta over ambient is ~ 27c while IDLE. I've tried re-seating the cooler plate after re-application of Arctic MX4 thermal compound, which is one of the best you can get. I have the best suited AIO liquid cooler currently available for TR4, and so I'm surprised at the idle temps on this. I have not yet been able to install windows, but I doubt it would make a difference. This is all from the UEFI.  Are there others out there who have had the same experience? I guess I should mention i am NOT overclocking this. Default settings, with 1.70 BIOS version. Why is using the UEFI UI considered idle? While only one core is actually being used in the UEFI, it is likely pegged near 100%. The other cores while doing nothing are getting the full VCore. None of the processor power saving options are active while in the UEFI. No influence from a power plan in the OS. VCore is constant in the UEFI. I haven't seen a recent platform, AMD or Intel, where the CPU temperature is not higher in the UEFI than in Windows. By a significant amount. Are you familiar with Ryzen's Tdie and Tctl temperature readings from the processor? The dies used in TRipper are the same or better than those used in the 1800X, which reports Tctl, which is Tdie plus a 20° C offset. You're seeing Tctl in the UEFI. You'll need to ask AMD why they have both Tdie and Tctl. Install Windows and then check your CPU temperature. It will be different than in the UEFI, guaranteed. Even then it depends upon which program you use. Don't expect all of them to use the same thing. HWiNFO64 will show both Tdie and Tctl. TRipper should report both Tdie and Tctl. Otherwise, what do you think is wrong? I use a 360mm radiator AIO CPU cooler with my Ryzen 1700X, I get UEFI temperatures a bit over 50° C. In Windows, idle temperature, Tdie is below 25° C. X399/TRipper, like Ryzen, is unique, you just need to experience it for a while. What system are you coming from that is so different?

Thank you for the detailed info. I was not aware that entering BIOS mode could load up a core to 100%. It makes no sense, but I'll take your word for it. It's a relief to know this. I'll look forward to seeing what is reported by HWINF064.

To answer your question, this is my first AMD build. I've been on Intel platforms since Pentium 3. My most recent Intel build was on the z170 chipset, with an Asrock mobo. Prior to that, x99, x68, whatever. I've never seen a 27c temperature difference between what the CPU monitor reports in BIOS and a Windows app like CoreTemp, for instance. So forgive me if I was a bit alarmed and thought there might be a problem. You seem to think it's commonplace, on that note I would disagree.

Hi!

I just wanted to say that I have the same experience.
X399 Taichi
TR1950X
Enermax Liqtech TR4 360

Immediately upon entering the BIOS the CPU temperature is reported as 62C. I've reseated the cooler which had no effect. I am using Arctic Silver 5 thermal paste.

In Linux, using the K10temps module in the latest Ubuntu kernel release (4.15), the idle/low load CPU temperature is reported at 23.9C.

Another poster suggested that the BIOS would be putting a full load on the CPU as well as maximum voltage thus generating a lot of heat. This makes no sense to me since I haven't seen this type of behaviour in any other build. The BIOS should not be stressing the CPU at all and if it is then that would be a different BIOS issue.

The fans on the cooler are running. The pump is attached to the CPU_OPT/W_PUMP header near the CPU socket. I have set this header in the BIOS to W_PUMP and the mode to DC rather than PWM (this did not change the temperatures reported in the BIOS). I may try using the supplied Molex adapter for the water pump and connect it directly to the power supply to see if the issue could be related to proper power being supplied to the water pump from the motherboard while in the BIOS.

On the other hand, maybe the CPU is that hot ... but as mentioned, I've never seen that previously.

Hi!

Just posting a quick followup.

X399 Taichi
1950X
Enermax Liqtech TR4 360

I am doing some stress testing running Prime95 on the 1950X while monitoring with hwinfo.

After about an hour of prime95 the CPU temperature (Tdie) is between 48C and 53C depending on when the fans kick up a notch - this happens at a Tctl value of 80C - the increased fans cool the CPU down until they slow again and it warms back up to 53C. Tctl is reported as 27C higher than Tdie since the offset for the 1950X is 27C (as far as I know).

Core utilization is pretty much 100% across the board. The chip is running stock (no BIOS overclocks) and the multipliers are reported as x37 on all cores ... which would tend to indicate that the AMD feature that increases clocks if there is sufficient cooling is working correctly since the base clock on the 1950X is x34.

Turning to the hwinfo temperature values apparently reported by the motherboard. The CPU temperature in the motherboard section is reported as 80C when Tctl is 80C and Tdie is 53C. The motherboard CPU temperature tracks the Tctl value reported.

According to another source which was discussing other Ryzen processors:

https://www.hwinfo.com/forum/Thread-Ryzen-1700x-temp-sensor-which-one?pid=13856#pid13856

Tctl is the temperature reported by the embedded CPU temperature sensor and includes the offset. For threadripper this would be 27C.
 
Based on this, it seems to me that the X399 Taichi just reports Tctl as the CPU temperature in the BIOS which includes the 27C offset for threadripper. As a result, the 62C reported in the BIOS actually represents a more reasonable 35C CPU temperature.

Anyway, folks can do their own research :) ... but it seems to me that the high CPU temperatures reported in the X399 Taichi BIOS are likely due to the 27C offset that is included in the temperature sensor data produced by the on-chip sensor in threadripper.