Severe performance issues on XPS 17 9720 after updating BIOS from 1.9.0 to 1.10.0

 I've found a workaround for this issue. I lock the MMIO through ThrottleStop. I can set PL1 to 45W again in this case, but the system is freezing on the Dell logo on restart:

Without this tweak in ThrottleStop, the laptop uses the 20W PL1 limit regardless of temperature, system load, selected power mode, etc.

At the same time, PL2 is set to 115W, and it works properly.

There are some issues with the new BIOS version (1.10.0).

I did some additional tests today.

I restarted the device, made a factory reset for BIOS settings, launched HWiNFO, and started the CB R23 MT test. The PL1 limit was set to 20W, and the CPU followed it:

Then I launched the ThrottleStop with locked MMIO and did the same testing:

Now the CPU behaves as it should and follows the MSR PL1 limit (75W). There's some thermal throttling, but it is expected considering chassis limitations and stock thermal interface.

All the tests were made while the device was plugged in. On battery, the issue is still there.

It looks like an issue with BIOS, which sets the incorrect power limit during the device initialization. It may be very noticeable because the performance drops by 40%.

I have made a 30-minute test in CB R23 MT today with no other apps running (including ThrottleStop). Here's how the 20W power limit looks:

For reference, with the default 45W PL1, the laptop achieves nearly 14000 points. I hope this issue will be fixed, and I won't need to use workarounds

I have found a workaround to fix an issue with the laptop restart with ThrottleStop enabled. I enabled the Sync MMIO option and set the correct PL1/PL2 levels:

At the same time, this issue is very confusing. I've paid $3700 for a laptop and want it to work according to the specs.

20W PL1 limit is unacceptable.

---

@TwistedAndy wrote:

Dell XPS 17 9720 with Core i9 12900HK and noticed severe performance issues. The performance under sustained load decreased by 40%.

1. Reset BIOS settings (both Factory and BIOS Defaults)

2. Reinstall and uninstall Dell Power Manager app and service

3. Loading Windows 11 in the Safe Mode.

---

I have a XPS-15 (9520) here ... which I think is similar. I haven't noticed any performance problems. I'm currently on Firmware/BIOS v1.4.0 (6-9-2022). 

1. Good. I've found it's usually better to leave all the TurboBoost and related settings Enabled/Auto (instead of turning them off and trying to force it higher or to max).

Have you checked Fan control? I use Optimized (I think the alternate Quiet setting might throttle).

2. Uninstalling it is a good idea (like maybe it's not quite-right and is limiting performance somehow).

3. Maybe just clean install Windows-11 and leave ALL the Dell stuff behind.

Your Throttle-Stop testing is informative. Dell will see it. Whether it is broken or by design would be for the Dell Engineers to decide. At least, you found a work-around.

Since it's a UltraBook (with expensive CPU and motherboard) I'm guessing that they try to keep them from melting down (as that is not good for anyone). Dead/fried machines don't render very well. That said, the Precision close-relative of this laptop might go higher (up to the edge).

Mine also has the Nvidia GeForce RTX-3050 (Laptop GPU version). When I get both the CPU and GPU cookin, seems like the engaged Nvidia card would allow the Intel Iris Xe graphics (IGP) to power-down or barely run. You would think this would provide more on-chip watts/thermal-space for the CPU-section to run closer to full-throttle. Still, I would try to run AfterBurner on the Nvidia with a slight power-limit on it (like maybe 10-20%) just because I don't want to damage it either (I'm not a big Over-Clocker or even believe in that).

Finally, be sure you are queuing-up way-enough work for the CPU/GPU. I've learned that is required to get everything cranked-up to full-speed.

---

@TwistedAndy wrote:

1. I've played around with Dell software, but in most cases, it is useless and doesn't affect my problem.

2. It is something managed by BIOS and its settings.

---

1. There have been reports of Support Assist and other Dell Apps interfering with various systems. A clean install (using microsoft.com installer) is one easy way to erase it all.

2. With UEFI systems, Windows can change options and BIOS, and vice-versa. There is little separation. 

Thanks again for posting the detailed and informative info.

1. I have done a clean Windows install two months ago with almost no Dell software (except Power Manager). The device worked flawlessly till the BIOS update.

2. In theory, Windows or some apps can change some unlocked system registers, but they usually don't do that.

At this point, I think I have a picture of what's going on and why I had an issue with the system restart with the MMIO lock.

BIOS sets the wrong power limits to the MMIO memory location during the device turn-on and initialization. It is something taking place before Windows starts loading.

When MMIO is locked, and I trigger the system restart, the BIOS performs a hybrid restart procedure when some memory contents (including MMIO lock) are kept in place.

As a result, during the initialization, the BIOS can't set power limits to MMIO because they are locked, and the laptop is freezing on the Dell logo.

This also explains why there are no issues if I shut down the device and turn it on again. All the memory contents, including the MMIO lock flag, during the shutdown are cleared.

Dell, could you fix this issue?

It's not too hard, please check the value set to PL1 during the device initialization and implement an additional check if the memory is not locked before changing it.

I'm not asking to fix the broken S3 sleep mode. It is something much more straightforward.

Weird my PL1 says 75.. not sure what is different.

PL1 set to 75W is also not the correct value. Actually, 75W is the PL1 MSR limit.

Your laptop will generate much more noise under load (47-48 dBA instead of 38-39 dBA with 45W PL1). That's a huge difference.

On the Dell XPS 17 9720, the default PL1 level is 45W in the Optimized and 55W in the Ultra Performance modes. Here are the correct power limits (screenshots were made in August on my device with the previous version of BIOS):

https://i.imgur.com/DPcqdFG.png This is my current and am still on the 1.9.0 I dont think I should upgrade. Also notice my score is higher than your was odd..

https://i.imgur.com/6MzKdei.jpeg 

I'll throw this in also just to see the power of the cpu on 1.9.0 dont think ill upgrade.

Adding alittle more to the topic. I do notice if I don't run Throttlestop the CPU will drop very low TDP maybe the 25w range and get me 1/2 the CPU score. If I always have Throttlestop running I will always get over 13k CPU score. Just fuel for the thought.  

Also that screenshot is using a eGPU with a dell 3080 RTX. My Scores without the eGPU are a tad above 7k total score vs 10,700ish

I suggest using HWiNFO to check the power limits. Also, I've noticed that PL1 may drop below 45W if you load your GPU heavily. But it may drop to 35W. That's the lowest value I saw.

Usually, under sustained loads CPU tends to run with 45W, which is optimal in terms of heat and noise.

As for your eGPU setup, have you checked the link speed? RTX 3080 should show much better results in TS (nearly 13-14K in eGPU mode)