PHVM_BR

You checked? Perhaps the contact between the heatsink and the CPU is bad. The gain in thermal headroom with PTM 7950 should be much higher...

Are these data with PTM 7950? Was the laptop on a stand or directly on the table? Room temperature too high? Was the application done well? Did you check the temperature difference between the cores? Check the P-cores and E-cores separately. If everything is ok the difference between the hottest and the least hot core under full load should be 5 to 7ºC, differentiating the P-cores from the E-cores. I'm questioning because sustaining 77W at ~90ºC is a disappointing result, especially if you're using PTM 7950. With the phase change pad my 7540 sustains 100W at 92-95ºC depending on ambient temperature and on a stand (no fan). I can't believe that after 4 years dell has downgraded the cooling of their Precision 7000 series...

When PL1 (77W) is reached and stabilized at what temperature? Your peak power seems too low...

Precision 5680 review... the author has confirmed that the TGP for RTX 5000 Ada is also 95W.

If you disabled core isolation/virtualization and it was still blocked it maybe that restoring factory defaults in BIOS would unlock undervolt. From a certain version of the BIOS, very old, it was necessary to restore the factory defaults to unlock the undervolt. Here without editing the BIOS the undervolt works on 1.24.0. If there really is a block it must have started in BIOS 1.25.0 or 1.26.1....

I have W10 Pro 22H2 here. Maybe just need to disable core isolation and virtualization features in W11 for undervolt.

I don't understand, my Precision 7540 is still in BIOS 1.24.0 and undervolt is unlocked. I didn't need to edit the BIOS to do a dervolt. Lock must have occurred in later version, 1.25.0... The power limits are interesting, in my case with i7-9750H, PL1=75W and PL2=90W, and sometimes I manage to increase them by checking the MMIO and MSR boxes in Throttlestop. It's something random, usually blocked, but I've managed to increase them a few times and they go back to default as soon as I restart the system... I have PTM 7950 applied since the beginning of the year and my undervolt is -250mV for the core and -130mV for the cache. Out of curiosity I tested it without undervolt and with the power limits at 107/107W and the i7-9750H needs ~100W to run Cinebench R23 mukticore with maximum clock (4.0GHz all cores). With my undervolt, which is 100% stable used since the purchase in December 2019, the consumption goes down to ~60W! About PTM 7950, without undervolt and at 4.0GHz all cores during the entire test on CB R23 consuming ~100W the processor remains at 95/97°C without throttling. With undervolt at ~60W the temperature drops by about 20°C and the fans only reach ~3900 rpm (the maximum is ~5150 rpm).

If the system receives the maximum of 165W it would be a disappointment... @Dell-Mano_G reported some time ago that the 5680 could benefit from the higher load using WD19DC. Maybe only on the stronger GPU options...

With around (75+75)W on the CPU and GPU both reach thermal limits. This will drain the battery even with the 165W charger... have you tested with WD19DC and verified if the system can pull more than the 165W of the original adapter? By dell thermal paste application history this 5680 seems to have a good potential after a repaste, even more in the versions with vapor chamber!

It is likely that your battery will be heavily drained, even plugged in, with the 130W charger. Interesting that these limits are well above the limits of the XPS 17 (9730) where the GPU is limited to 60/70W and the limit on CPU+GPU cross-loads is something like 90/95W. Probably the options with stronger GPUs have a little higher TGP...maybe something between 110 and 130W.

What is your GPU? Could you check the max TGP entered in the Nvidia control panel?

Mine probably has that whistling sound you report, but it only occurs when the fans turn up to a high level, for a short period. If I really go ahead and change the motherboard I'll remember and post some pictures of the fans.

maybe 1, 1.5 and 2mm...

If I change the motherboard I will take advantage and change the thermal pads. Despite having experience changing thermal paste, I never changed the pads. Does anyone have an indication of the thickness of the pads on the Precision 7540? What are the best ones I can use?

5680 has vapor chamber option (owner's manual) but no indication as to which configuration it is available from. Maybe from RTX 3500 Ada?

If I really go ahead and have any difficulties along the way, I'm asking for help! Thanks again!

I've opened this system a few times but not at the level of replacing the motherboard. I believe everything is fine. As for the price, I got a new one with i9-9880H for 340 US dollars. What do you think?

Thank you very much for the quick and detailed response! As for the gain or not with 8 cores, yes my load is multicore and yes I will have an expressive gain since with the i7 I still have a good thermal space. My consumption at full load with maximum clocks (4.0GHz all cores) is only ~60W with my undervolt setting and the PL1 is 75W. Furthermore, with PTM 7950 I can sustain up to 100W without thermal throttling (95-97ºC) in medium-term loads. I'd say 90W can be sustained all the time at 88-92ºC.

I have a CPU bottleneck in my workflow. 6 cores are slowing down my life and so I'm thinking of buying a motherboard with i9, or 9880H or 9980HK, for my Precison 7540 with i7-9750H and Quadro T2000. Is there anything I should be concerned about or just replace the motherboard and everything will work? My other option would be to buy another machine, but the Precision 7670/7680 didn't attract me. I believe with i9 with 8 cores it will serve me for another 2 or 3 years...

@Dell-Mano_G Any news about the launch of the Precision 5480? I had read that the date would be April 20th...

Maybe in the moments of change the level of rotation, but as I said, it doesn't bother me. I used the phase change pad version and I believe it is the best option to avoid flow out delivering long-term durability.

Unfortunately I never checked. It never bothered me, although at maximum speed it is quite high (~5100rpm). I last opened the laptop in February and did the repast with PTM 7950. I don't think I'm going to open it for a long time... The performance is fantastic!

In the case of the Precision 7540 with T2000 the heatsink is the same as the version with RTX3000? Good to know!

Does anyone know if the new BIOS 1.25.0 blocks the undervolt?

Try changing to AHCI in BIOS.