Precision 7550 & Precision 7750 owner's thread

[heikkuri]

This is warning about latest BIOS 1.24.0, release date 09 Aug 2023.

If you use Dell dock WD19DC only one cable light is on so you do not get enough power etc.

I have done all know reset etc. tricks. Nothing helps. BIOS downgrade fails.

 

Best temporary fix is to use Thunderbolt dock WD19TB and use Dell Precision 7X50 own charger as extra power source.

Now the all external displays work again.

 

Last good known BIOS is version 1.23.1, release date 20 Jun 2023.

 

Here is more discussion if you are interested

‎Dell Precision 7550 and 7750 System BIOS - 1.24.0 Breaks Docking Station USB C | DELL Technologies

 

The faulty BIOS file is still available for download.

 

 

 

[ÊtaPegasus]

Hello everyone,

 

I'm looking for some advice here.

I've been trying to take advantage of the 5.1GHz boost clock of my i7-10850h but it seems that i'm thermally limited way before i can achieve such multi core speed (i use PTM7950 by the way).

 

Several things have been bothering me :

- Every time i open a brower, launch a game or windows launch an update, the CPU would boost to 5.1GHz and reach immediately at 100°C --> hence a lot of fan noise and heat

- Linked to the behaviour described previously, gaming with 5.1GHz boost would only give higher temperature and power consumption and almost no gain

 

So i tried to understand how was the boost algorithm working on this 6 core 10th gen, and lo and behold, the voltage required to boost above 4.0GHz seems absurd to me on a laptop chip : almost 1.35V for reaching 5.1GHz...

Secondly, i tried to run CineBench R20 to evaluate if there was a point of diminishing returns : yes there is, at 4.0GHz i'm reaching the PL1=75W and 90°C, so no gain going higher imo.
 

 

I'm actually using theses settings to take temperature under control :

- Prochot limit redueced to 90°C (instead of 100°C via Throttlestop)

- Power package limit to 75W PL1 and PL2 (instead of 135W PL1 / 75W PL2)

- Max multiplier limited to x40 (instead of x51 via Throttlestop) --> This limit a lot of the temperature peaks due to the lower core voltage needed to stay at 4.0GHz --> i still get 92% of the single core performance (compared to 5.1GHz) with almost 15°C reduction.

 

Are there other people owning a Dell Precision 7550 that can confirm this thermal behaviour? If not, any advice on how to improve the thermal performance?

[PHVM_BR]

On 9/29/2024 at 4:28 AM, ÊtaPegasus said:

Hello everyone,

 

I'm looking for some advice here.

I've been trying to take advantage of the 5.1GHz boost clock of my i7-10850h but it seems that i'm thermally limited way before i can achieve such multi core speed (i use PTM7950 by the way).

 

Several things have been bothering me :

- Every time i open a brower, launch a game or windows launch an update, the CPU would boost to 5.1GHz and reach immediately at 100°C --> hence a lot of fan noise and heat

- Linked to the behaviour described previously, gaming with 5.1GHz boost would only give higher temperature and power consumption and almost no gain

 

So i tried to understand how was the boost algorithm working on this 6 core 10th gen, and lo and behold, the voltage required to boost above 4.0GHz seems absurd to me on a laptop chip : almost 1.35V for reaching 5.1GHz...

Secondly, i tried to run CineBench R20 to evaluate if there was a point of diminishing returns : yes there is, at 4.0GHz i'm reaching the PL1=75W and 90°C, so no gain going higher imo.
 

 

I'm actually using theses settings to take temperature under control :

- Prochot limit redueced to 90°C (instead of 100°C via Throttlestop)

- Power package limit to 75W PL1 and PL2 (instead of 135W PL1 / 75W PL2)

- Max multiplier limited to x40 (instead of x51 via Throttlestop) --> This limit a lot of the temperature peaks due to the lower core voltage needed to stay at 4.0GHz --> i still get 92% of the single core performance (compared to 5.1GHz) with almost 15°C reduction.

 

Are there other people owning a Dell Precision 7550 that can confirm this thermal behaviour? If not, any advice on how to improve the thermal performance?

In full load multicore like Cinebench, the i7-10850H's default maximum clock rate is 4.4GHz.

 

5.1GHz is only reached in lighter loads that only require a single core.

 

You don't obtain benefits above 4.0GHz in Cinebench due to thermal limitation.

 

Without throttling and maintaining 4.4GHz on all cores you would have a proportionally better score (~10%).

 

I don't have a 7550, but I do have a 7540 and mine can sustain ~100W in medium duration loads (up to 2 or 3 minutes) with PTM 7950 and a laptop stand to move the air intake away from the table top.

 

Around 90W is possible for long periods without thermal limitation.

 

It's strange that your 7550 with PTM 7950 has a lower thermal headroom than my 7540 because all the reports I've seen state that the 7550 has slightly better cooling capacity than its predecessor (maybe ~10 or 15%)...

 

Maybe it's a bad application or the lack of good contact between the heatsink and the die.

 

I would check the temperature difference between the cores during a full load (Cinebench).

 

Generally, 8th/9th/10th Intel CPUs with 6 cores have a difference of around 5 to 7°C between the hottest and least hot cores when there is a good application of the thermal compound.

 

A difference of up to 10°C is valid, more than that could mean your application failed.

 

This applies to full loads.

 

On my 7540 I also discovered that KryoSheet can deliver more than PTM 7950 (if there is good heatsink contact).

 

With KryoSheet I can sustain energy consumption around 15% more than with PTM 7950 (~107W for long term heavy loads).

 

You can also enable undervolt with a simple BIOS edit and thus achieve higher clocks with the same current power consumption.

[TheQuentincc]

I could sustain 115W load in cool environement with my 7550 and 10875H (8 cores) with liquid metal. Nearly reaching 4.3GHz max all-core with undervolting.

 

I'm using throttlestop to undervolt the CPU, force a more "relax" performance state (speedshift EPP 196) for browsing and disable turbo while I'm not needing any performance (such as browsing).

When requiring higher performance I usually limit the CPU turbo to 3.6~4GHz on all core using the FIVR tab and push the speedshit EPP to 128 ("balanced mode" I would say). For gaming 3.2GHz seems to be the sweet spot (maybe since you have a 6 core you might need a bit more frequency).

Regarding heat output the main thing to be careful is the dGPU, you should always monitor which app is using the dGPU (even at idle it's a constant 15w heat output, you can enable the activity icon through the Nvidia control panel).

 

I also have an XPS 9500 with a far inferior cooling that I'm dailying with an I7 10750H, disabled turbo, undervolting and speedshift EPP at 196. It's doing wonder for daily usage without noticeable slow down and a fan that spun like 5~10% of the time every few minutes at slow speed depending on the weight of the web page.

[ÊtaPegasus]

Thanks for your replies.

I checked my cpu temps du ring CB20 run and the temperature scatter was around 7°C across all cores. I guess my PTM7950 application is valid then ?

 

I found another thing through : when I swapped my Nvidia Quadro T1000 for the Nvidia RTX 5000 max-q, I kept the same fan/heatsink assembly.

Checking again on part People, there seems to be 2 different heatsink assembly P/N for Quadro T1000/2000 cards (first picture - P/N  3XNJY) and RTX cards (second picture - P/N 0VP47) but I can't see any noticeable differences based on the pictures (the GPU seems a little bigger and the fan fin array a bit different too).

Could you tell me wich heatsink you actually have and if the différence between them is signifiant enough to justify the replacement ?

Edited October 26 by ÊtaPegasus
Adding photos to illustrate my question

[ÊtaPegasus]

For the sake of the experiment, i purchased a brand new 0VP47 heatsink on ebay. I can confirm, the GPU plate is slightly different and the fans are different (their noise is better in my opinion).

With stock paste, i can now sustain up to 110W on CineBench R20 and keep the clocks to 4.4GHz on almost all the run.

 

So the heatsink was the culprit after all. I will repaste with PTM7950 and see if there are any more improvement.