XPS 15 9570, i9 thermals, throttling and solutions

Hi! Does your solution methods also work on i7 xps 15 9570? Thank you for sharing!

Did you check the temperatures in the "Dell EC" group using HWinfo64, in particular the first Ambient and DIMM? (Mind the sensor labels may not be the same in Aida)

> You cannot do a lot against the power limit throttling (which is good) 

I don't think throttling is good. It may not be avoidable with the i9 9570, but it can likely be reduced.

VRM heat is the main problem. Did you pad the VRM mosfets? iunlock's mod for the 9560 seems to be the best known solution, but it is a bit involved. 

After you take care of VRM heat, you can consider padding the RAM, particularly the DIMM sensor in between the sticks that appears to trigger PL throttling at 63 in the 9570. To the backplate (but assuming you haven't padded VRM mosfets to the backplate). This should reduce PL throttling.  

Hi samos,

>>Did you check the temperatures in the "Dell EC" group using HWinfo64, in particular the first Ambient and DIMM?

Yes, AIDA is not as good as i thought in the first place. So now everything is being monitored with HWiNFO64.

I tested multiple mods out there - padding the VRMs / Mosfets to the backplate had the most success. The heating of the backplate is not heating up the fan's air too much because the surface that comes into contact with the air is fairly minimal (and additionally cools the backplate).

>>I don't think throttling is good.

Right, let me put it this way - a slim laptop consuming more than 130W over a longer time will glow in the dark. So with the current 14nm++ technology, this kind of laptop should not use more power (at least with this kind of cooling technology).

I will try padding the DIMMs - the backplate in this area is fairly cool even though the VRMs are heatbridged to it as well.

> I tested multiple mods out there - padding the VRMs / Mosfets to the backplate had the most success. The heating of the backplate is not heating up the fan's air too much because the surface that comes into contact with the air is fairly minimal (and additionally cools the backplate).

This is known to help a little bit, though not so much. But when folks tried better Fujipoly pads, the long-term performance deterioration has shown up. It is okay if using a laptop cooler stand, but actually worse without. 

> Right, let me put it this way - a slim laptop consuming more than 130W over a longer time will glow in the dark. So with the current 14nm++ technology, this kind of laptop should not use more power (at least with this kind of cooling technology). 

iunlock's mod was successful in making the i7 9560 run unthrottled. It took him quite a lot of effort to come up with, and still takes an effort to repeat. But it shows it is feasible in the same space (not sure if also for the new 6-core CPUs, despite the same TDP in the i7). For manufacturing, cooling would have to be redesigned of course. Looking at some other laptop designs, they could extend the radiators a little bit, and add another small heatpipe for the VRMs.  

I keep getting the problem on my XPS 9570 i7 8750h, I did all of your steps but it fixes it for a bit and the problem keeps coming back, When I run Cinnabench R15 my score is in the 400's but when I first received my xps two days ago i was getting 1,200's

@pep0sn

 >In addition to that I experimented with undervolting (ThrottleStop and Intel XPU (*edit: use ThrottleStop only)). Undervolting the CPU/CPU Cache at -80mV-100mV brings the CPU temp down even more and you can get a bit more clock frequency at the same power limit (e.g. AIDA CPU only test before: 3.52 Ghz (no temp throttling, power limit 56W), after: 3.82Ghz (no temp throttling, power limit 56W))

Wait hold on. Are you sure you are running at the 56W PL1 limit when doing 3.82ghz? I've basically done everything you've done and yet my 56W limit is still 3.5ghz. Can you confirm with throttle st

Hi @ApplesOfEpicness

did you perhaps enable the FPU / Cache stress test as well? I tested only with the CPU stress test active (Screenshot):

This is with -99.6mV (CPU and CPU Cache)

In the 400s? That's very low. Sounds like your CPU is throttled to a minimum. Can you open the Intel Power Gadget while your Cinebench is running to keep track of your clock frequency?

Pep0sn, 

could you report what CPU clocks you get initially and what after 15 min of the Prime95 stress test (blend)

a) with 12 threads 

b) with a single thread? 

and after how many seconds PL throttling kicks in?

It appears the i9 power limits are locked down in BIOS and that its long-term turbo clocks (which depend on the number of cores loaded) are lower than some other machines running an i7. 

Hi samos,

12 Threads
- initially, the clock frequency is around 3.7-3.9Ghz for around 32 seconds (then PL1 kicks in)
- after around 20 Minutes, the clock frequency is stable at around 3.1-3.2 Ghz (PL1 56W)
- after around 20 Minutes, temperature is constant at around 79-81°C
- after around 20 Minutes, total system power consumption is constant at around 95-97W

1 Thread
- initially, clock frequ. between 4.1-4.6Ghz (Package Power around 47W)
- stays like that after 10-12 minutes, frequency fluctuating (3.8-4.6Ghz)depending on specifics of the performed test
- package temperature around 80-86° (sometimes dipping higher)
- no thermal throttling but PL4 (Max VR Voltage) is Yes in HWiNFO

Thank you. Intel doesn't seem to publish a table of max boost frequencies vs the number of cores anymore, but long-term 3.1-3.2 Ghz is less than what some others get with i7-8750H based laptops (i5-8300H report even higher clocks but these have 4 cores not 6). 

> In all core cinebench for example, clock speeds are higher while all cores being under 100% load.

Yes the clocks in Cinebench are higher, I guess the CPU load is intermittent not so continuous as in Prime95

It's hard to compare those. CPU frequency also depends on workload (tested chipset command branches). i5 may have to ramp up more Ghz with a higher load overall than an i7/i9 would.

In all core cinebench for example, clock speeds are higher while all cores being under 100% load.

@pep0sn

Ah, I see. Yeah I've been running cinebench with stresses the whole CPU. That makes sense because not stressing cache and fpu reduces power consumption and increases my clock speed. I really wish dell allowed advanced bios editing so I could increase the power limits. I have so much headroom and no ability to utilize it.