XPS 15 underclocking, stuck at 0.78 GHz

Hello,

I have had my XPS 15 9550 for about a year now, the i5 model. This week I have noticed a decrease in performance, especially during gaming, and after a lot of research I could finally narrow it down to the CPU, always stuck at 0.78GHz, no matter whether plugged in or on battery, no matter what program I'm running.

I've done a full reset and updated all drivers and BIOS again, checked the Power Plans but nothing would change the issue.

I came across this software called ThrottleStop that has a function called BD PROCHOT which, when unchecked, actually fixes the issue and the processor goes back to full speed, but only for as long as ThrottleStop is running... So it's not a permanent solution...

Is somehting faulty with the machine itself? What do you think?

Many thanks

 

Turn off the PC. Hold down the power button for like 5-10 seconds. I believe it'll cycle a power on/off quickly. Basically it factory resets the bios when you do this... boot up and give it a try.
I believe there's also a dell diagnostics for booting... like holding D when booting or something... Not sure, google that... but start with the holding the power down.

 

Thank you. I've tried that, holding down the power button didn't seem to trigger anything different from the usual boot sequence. Pressing F2 during the Dell logo screen starts the BIOS menu, there is an option to format the BIOS to factory defaults, which I did... but nothing has changed still

I found online some other users having a similar issue and using this software called ThrottleStop, that lets you disable something called BD PROCHOT. This does work for me too, but only while the software is running, so I am thinking it's not probably a permanent solution...

 

Holding the power can cure a random issue but it doesn't reset the BIOS, and D is monitor diagnostics.

Install Dell Power Command and swap the profile to high performance then back to normal assuming it work on high performance.

 

Thanks GoNz0. I tried again, holding down power for up to 30 seconds but it doesn't seem to have any effect on my XPS. I have read online of other users doing this after removing the battery... Which means I'd have to find a way to unscrew the bottom lid to get to it somehow...

I will try the Power Command option, see what that does...

Thanks!

 

It is worth a try as it changes BIOS setting.

 

Got Dell Command Power Manager, the only section that I could see as having an impact on CPU was the Thermal Management one, where I set the Thermal Setting to Ultra performance.... still to no avail Unless I am missing out some options...

Seems i might need to try remove the case and the battery and do power down... If I can find something to unscrew these tiny little screws with!!

 

How are your temps?

 

This is the temps at idle:


These are the temps while running a game in the background


Temps seem low either way, don't they? Clearly something wrong with that clock rate stuck at 0.78

 

Have you tried resetting the BIOS to defaults?

 

Tried unplugging the battery and powering on? Some people got their random throttling fixed that way. ThrottleStop is a great programme, btw. I leave it running in the tray on all my machines.

 

Yes. I did that from the BIOS menu when pressing F2 on startup. Reset them to factory defaults, also tried re updating the BIOS to latest and rolled back one version.... Nothing

 

Thanks Eason! I don't really have a screw driver small enough to unscrew the bottom panel and get the battery out, might need to go to a PC specialist for that... I really wanna try that too as many people mentioned solving this with a hard power down with battery unplugged.

I am still uncertain as to how ThrottleStop is working... I don't understand if I have to start it up each time I boot the machine and uncheck BD PROCHOT to address this issue, or whether I need to save this profile somewhere and it keeps it this way? What I can tell for sure is that the machine goes back to working to its full speed when I uncheck that box.

Is this not unsafe for the machine in any way? Forcing the CPU to the highest clock when not needed? I read it can cause overheating problems...

Thanks for any wisdom you can share!

 

Have it autorun when you boot up. TS uses up to 4 profiles, but by default will just stick to the one you leave it set to. I recommend setting your power plan to "high performance", using TS, and simply unchecking "bdprochot" and checking "power saver". That should allow your clocks to go full. If not, try checking the multiplier box. I set TS to turn off while on battery power, and just let the computer switch to "power saver" or "balanced" profile.

If you're going to own laptops, it's a good idea to have a full screwdriver kit with all the heads. T5 is going to be the most common for expensive laptops.

It's totally safe to run the machine at any clocks you can as long as the temperature is ok. I don't like my temps going above 80 for anything except short periods.

Oh, another advantage of TS is that you can undervolt your CPU to save battery life and lower heat. Check the guide in my sig.

If you want see how far the rabbit hole goes... there's the throttlestop guide

 

Thank you, super informative! I will stick to TS for now then. I have been trying to look for an option inside the software to boot up with Windows, but I can't seem to find it, I guess the answer is somewhere in that thread you linked to...

Many thanks again for all the advice!

 

Use task manager. Add it as a startup event.

 

Found this thread on reddit. Don't reallly find reddit useful except to waste away time but this might help..someone else had an issue. https://www.reddit.com/r/Dell/comments/5uh6wo/fixing_your_dell_xps_cpu_stuck_at_minimum/

 

To auto start ThrottleStop with Windows, use the Task Scheduler. Here's how.

http://forum.notebookreview.com/threads/the-throttlestop-guide.531329/page-514#post-10366647

 

For anybody incurring into this issue, the solution is in fact, to disconnect the battery. I unscrewed the back panel for the first time in a year that I had the laptop, the fans were very very dusty, so that might have been the actual cause... but like some other users suggested, I disconnected the the battery and reconnected it... The laptop doesn't underclock anymore now! Yay!

 

I had this issue but it is now resolved. Read how below.

Likely the main issue was I hadn't installed all drivers because I used my own Windows installer media, rather than the one that came preinstalled with the laptop.

After I installed the "Intel Dynamic Platform and Thermal Framework" driver available at http://www.dell.com/support/home/se/sv/sebsdt1/drivers/driversdetails?driverId=JTXD1, this issue has not arisen again.


Kind regards,
Ulf
Sweden

 

I've been meaning to add TS to run automatically at startup for a while. Happy days!

 

I had exactly the same problem: CPU speed is always 0.78 GHz. BIOS reset, downgrade, or upgrade didn't work. Disconnecting and reconnecting the battery really worked!

 

This suggestion really worked! Thanks. How does battery disconnection and reconnection work??