Zbook 17 G6 low CPU power limit

[poprostujakub]

I recently bought second-hand Zbook 17 G6 and it has strange problem - maximum power CPU can draw steadily is 30 watts, despite HWInfo stating it's 55/110 watts. Rarely I see spikes to 47 watts. Laptop has no dedicated GPU at the moment and power brick is 230 watts. CPU temperature at full load is around 75 °C. Full load frequency settles at 2.8 GHz which is very dissapointing. 

[1610ftw]

Which CPU do you have and what are your settings in power options?

 

You want max CPU power at 100% at least when connected to power. Even at 99% the turbo boost will be disabled and it may be that this is happening and/or you are stuck in power saving mode. At 2.9GHz you probably have the Xeon E-2286M?

[poprostujakub]

i7-9850H. But I think that I resolved the case - it does this without battery. I have it partly disassembled because it waits for GPU so I didn't put battery in it. With battery clocks spikes to 4.6 GHz at about 100 W (and then thermal throttes by 20% according to HWInfo) then drops to 55 W at 3.6 GHz and 85 °C. But I'm dissapointed in cooling solution and fan curve, they would be good for multimedia use, not for workstation. 

[1610ftw]

3 hours ago, poprostujakub said:

i7-9850H. But I think that I resolved the case - it does this without battery. I have it partly disassembled because it waits for GPU so I didn't put battery in it. With battery clocks spikes to 4.6 GHz at about 100 W (and then thermal throttes by 20% according to HWInfo) then drops to 55 W at 3.6 GHz and 85 °C. But I'm dissapointed in cooling solution and fan curve, they would be good for multimedia use, not for workstation. 

 

That is indeed interesting and another design fail.

Unfortunately my Zbook 17 G6 is also the one laptop that empties its battery in record time when not connected and I haven't had time to get to the bottom of it.

 

The fan curve is really stupid. I suggest to get PWM7950 for it to keep temps as low as possible but even then the fan curve is severely limiting power due to its emphasis of silence over anything else.

 

If you ran updates already then it probably does not matter any more but if you haven't you should block bios updates in device manager as previous bios versions would allow third party fan control and undervolting via Throttlestop or Intel XTU but HP took all of that away in later bios.

 

What I would do to mitigate issues further is to use Intel XTU in order to limit maximum CPU power to something like 75 or 80W and you can also try to limit the hottest cores to lower max clock speeds - usually the 9850H will run very hot on a core or too which will cause it to throttle a lot faster than needed. If that is not possible you can still use Throttlestop to limit maximum power to the CPU and again I would go for 75 or 80W as that will give you a more even user experience than the spiking that you get when power is ramping up to 100W. I am also not sure if it is possible to go back to an earlier bios but I am lucky in that I am in a situation where I do not have to risk going back as my use case is such that I can live with the current fan curve.

 

This is a magnificent chassis with very bad software and on top of that is is also completely locked down in the final bios version which is a worst case combination. Because of that it will also be my last HP laptop for now until I see that they have a design that has great hardware AND software.

 

 

[poprostujakub]

Yes, I was impressed by the amount of expansion slots on the MB and rigidity of the chassis. I'm experimenting with custom fan driver built using Arduino Nano SuperMini stuffed into unused CD drive bay, but as good I am at electronics, I am bad at programming, so with current algorythm fans are very jerky when switching from fast changing MB signal to slow creeping input from thermistors I've glued near the VRM's (whichever is higher sets PWM duty for the fans), but I believe that after some more iterations it will be usable and maybe I will also use it my P870DM (stuffed with RTX5000 stolen from this HP, with incompatible temperature reporting 😆). 

Thanks for the advices, I'll check how much more watts I can squeeze. As for the uneven core heating, I tried bending cooling and added second springs to screws around CPU which mitigated this problem a little. I wonder if more powerful fans EG85100S1-C100-S9A from Fury 16 G10 i9+RTX5000 would fit, but they're way to pricey for now to play around.