BIOS BUG REPORT: XPS 15 9550, CPU Speed capped after switching from battery to AC power

Thank you for keeping us updated :)

Hi,

I've been in contact with Engineering today and they have been able to replicate the CPU speed issue and they have managed to resolve it. The resolution has been confirmed as stable on the 9550.

The resolution will be included in the BIOS revision 01.01.11 that will be released in mid December - I can't give a definitive date as right now the release date is unknown - but once it is released I'll update the thread with the link.

While you wait for the BIOS to be released, please follow any of the 3 workarounds below if the issue occurs on your 9550. Either:

1. Put the system in to sleep mode and then wake it up

2. Restart the system

3. Disable Speedstep in the BIOS

Feel free to share this post on the various other Forums that have been posting about the issue, so that the users there are aware there is a BIOS update coming to resolve this.

Thank you for the update!

I can confirm this problem also occurs on the new Precision 5510.

I have a similar problem on the Inspiron 7353 with i7 6500U.  Out of the box TurboBoost seems to be disabled regardless of BIOS setting  (processor capped at 2.5GHz, instead of 3.1GHZ)

Upgrading the "Intel Dynamic Platform and Thermal Framework" drivers (to version 8.1.10603.192) in Device Manager fixed the problem.

Thank you for the update Colin. I was starting to get a little worried, but my confidence is restored now that I know a solution is being worked on. :)

Colin,

Can you please provide an eta on the hot fix?

I'm still a little worried. The update isn't out yet.

I am also having stability issues with screen flickering when running 2 or more external monitors using USB-C -> Display Port. I've tried 3 cables so far. I can run it, and usually, it requires me to shutdown/boot into windows before I dock for the day. When it goes into sleep, I have to turn my monitors off and back on for them to work or for more than 1 to work as they are daisy chained. Debated putting into another thread. 

Plus now, w/ my XPS 9550, less than 30 days old, my space-bar squeaks, and, I hear some small electrical feedback coming from in the computer.

I'm still a little worried. The update isn't out yet....Plus now, w/ my XPS 9550, less than 30 days old, my space-bar squeaks, and, I hear some small electrical feedback coming from in the computer.

On my second XPS 9550 now.  On the first one, the space bar turned into a squeaky mess after about three weeks.  Exchanged at Best Buy at the 30 day mark.  Got the second XPS 9550 a week ago, which has no problem with the space bar.  If the speed cap isn't fixed at the 30 day mark, will exchange again to reset the return timer.  

I won't risk being stuck with this machine until Dell has fixed the speed cap bug.  This BIOS bug has been known for a long time and the fix should have been pushed out immediately.

this is exactly what i'm thinking too...just got this laptop barely 2 weeks ago and its BSOD at least once a day. i was a huge fan of this machine but now i'm not even sure if i would want to exchange it for the same system with the same problems or just go in a different direction. anyone have any suggestions? as i'm going to process a return tomorrow

Unfortunately there is still no update on the ETA for the BIOS being released. It's still scheduled for release in Mid December. I've got no concrete dates or information other than that.

When I have more info I'll post back here to let you know

Keep it. This problem is fixed. I have tested the latest BIOS 1.1.11 and can confirm it is fixed. Just wait a little while longer and you'll be happy.

How did you get access to that BIOS version?

I see. However, I've seen you say "mid december" multiple times in this post. In my book, we're close to the end of december. Will this issue atleast be fixed this year?