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

I kgor a surface book instead.  Yes it is not as powerful spec wise but since the cpu does not work to spec and the manymanyissues that make this comp a paper weight the book is such a better choice.  I had issues with 3 books but the fourth is smooth and working great.  Microsoft has publically said we have issues that we will fix and have been working overtime to deal with.  Dell seems to be on vacation.  Like someone saying we will get to it when we get to it.  Then half assing the issue and saying we will fix it chill.  Such a *** computer.  The worst part is when you call tech support they say we have no record of this issue.  No matter what you say.  Seriously dell you *** a big one.  Also i do not fault dells social tep colin.  Hos hands are tied.  The Sr as you said and the people who should be dealing with all the issues are to blame.  These issues are going on 2 months lol.  So sad.  People called me dumb for getting a first generation laptop.  Dells xps 15 is not a first gen at all.  

Do you wipe your *** with toilet paper that already has *** on it.  I mean its still useable with your definition.

I don't even know what to say... Some people just refuse to grow up

Dell needs to get focused on this issue. The throttling bug has been reported by a major review site and included in the review for all to see.  The review can be found here:

www.notebookcheck.net/Dell-XPS-15-2016-9550-InfinityEdge-Notebook-Review.156354.0.html

Look under the performance section.

I have the same issue, I've found disabling speedstep helps.

However my CPU seems to throttle randomly whilst browsing, it'll just sit at 0.6ghz and everything is very laggy, after 15 minutes it improves again, this issue stops to some extent when I disable speedstep.

I also find after a 15 minutes of gaming my fps tanks and from what I can see in MSI Afterburner the GPU usage for the 960m drops down to 10-20%, and GPU 2 aka Intel graphics shoots up to 100%.

I'm not sure if its part of the same problem or if I have two issue's here. Disabling speedstep seems to help  a bit.

I confirm same issue here: performance slowdown,cpu overload

XPS 15 9550

SDD 32, 1T HDD, i7

I can understand them wanting to fix the runtime issue since it can open Dell up to false claims of performance (GTX 970 anybody?) but, personally, that 1hour+ means nothing to me.  I would have been happy with the throttle/NVMe fix.  Let's see how long it takes to iron out that runtime issue, assuming it is at all possible.

I have same issue as reported by you

Same issue with  Bios version 01.00.07  Build date Dec-16-2015

In power option Would set min and max processor state to "100"  

on battery it would get to 2.57 witch is fine  considering max shown as 2.60 and it is battery after all need to conserve a bit lol

but as soon as I plug the AC it lowers speed to 1.66 instantly (capping  when AC plugged in) but when unplug it will go up to 2.57

putting computer to sleep with AC on will boost to 2.60 -2-78 considering laptop don't have a load.

also  FYI  not sure if that's by design Did a stress test and I was not able to get CPU speed higher then 3.07-3.10  it  was  advertised 3.60 I believe.

Wish the manufacturer's stop misleading the promised specification.

Hope they will fix this bug/settings in future updates soon as this is suppose to be premium line XPS after all lol sure seems to be when it is priced that way.

Several comments:

Speed Step should usually be defeated. Then you shouldn't need to set min and max speeds to 100%. Did you set both the battery and AC sections to 100%? You did not specify but I assume you did both.

Periodic slow downs can be caused by overheating. After cooling because of the slower clock, speed increases to the max, thwn cycles downand up. Did anyone check CPU/GPU temperatures? Could be a problem with the BIOS temperature/fan control program.

This type of problem has occurred before, and was caused by underpowered power supplies. Increasing to the next higher output supply cured the problem. However, this could also be a BIOS issue where the voltage/current values that the BIOS uses to determine if enough power is available to both run the laptop and charge the battery.

Sorry I don't have a pat answer. These problems can be difficult to solve.

Yep both set at 100% so to see the diference

when on battery it always gets in the 2.5 with max 2.6 but as soon as plugging AC drops instantly to 1.6 restart/sleep bring the  clock speed up on AC.

Did clean install same issue.

hoping for that miracle patch lol

Thanks

Hi guys,

Might be a stupid question but if they manage to fix this problem in the new bios, will I be able to safely install it from an older version of the bios? i.e I am running bios 1.00.05 as opposed to the latest available version being 1.00.07. Do I need to first update to 0.7?

Thanks

Ivan

Hi everyone, just a quick question that may be stupid. When they eventually release this updated bios to fix the problem, can you update your system to the latest bios from an older version? i.e I am running 0.5 however the latest bios available is 0.7. Will it damage my computer to update from my current bios?

Thanks

Ivan

If not stated otherwise, you should be able to jump from one another without going through all the versions, as common BIOS updates erase then rewrite the whole dedicated EEPROM.

I sure hope this is a BIOS issue and not something as sinister as an underpowered PS.  If it is indeed a PS issue, Dell needs to immediately stop the sales of all XPS 15 9550 machines.  Then figure out how to best handle the problem with machines sold.

It never occurred to me they would be naive enough to under power this laptop.