Dell Inspiron with i7-1255U - Too much throttling

[tcholgas]

Hello!

I just got a dell inspiron with an i7-1255U as my work computer. I've read in lot's of places that the "U" ones are really bad for heavy tasks (I work with geoprocessing) and that the throttling on them is just ridiculos, and I can confirm that now that I've used it for some time.

The CPU wont go anywhere above 70 degrees celsius. Whenever I open ANY software, the CPU clock cuts down to about 0,7-0,9 Ghz.

On the Limits tab, it's ALWAYS PL1 and PL2 RED thtorttling, ALWAYS. No matter what i'm doing in the PC.

I've tried some things that I've seen here on the forums but nothing seems to work, not even editing PL1 and PL2 limits by hand.


I was wondering if anyone knows a workaround with these i7-1255U.

Why do these PCs have i7s if they run like a i3 from the 5th gen is beyond me.

Thanks all in advance!

 

[tcholgas]

Best way I got it so far:

Still i'm getting insane Max temps at 100 all the time. The notebook is months old, it's not dirty and it's got a cooling base on at all times.

Even when only getting 20-24W (CPU max is 55W) it overheats like hell.

I'm kinda giving up and just asking for a replacement, is there any hope at all for these "U" CPU notebooks at all?

 

[PHVM_BR]

Change the thermal paste and your notebook will have considerably higher and more consistent performance.

Dell uses low quality thermal compound and there are still recurring and several cases of poor factory application.

The ideal one to use is PTM 7950, but even a good thermal paste like Noctua NT-H2, properly applied, will make a considerable difference.

Another point is to select ultra performance mode in BIOS or Dell Power Manager or MyDell.

This increases CPU limits as well as fan speed.

 

[unclewebb]

Whenever I open ANY software, the CPU clock cuts down to about 0,7-0,9 Ghz.

Check the ThrottleStop Log File box and run a log file while you are using your computer and it is throttling. Try to run your computer for 10 minutes so there is an adequate amount of data. When done testing, exit ThrottleStop so it can finalize the log file. Attach a log file to your next post.

CPU max is 55W

The 1255U has a 15W TDP power rating. Manufacturers design heatsinks and fans based on that specification. If a manufacturer or end user decides to increase the turbo power limits, the CPU will run hot and it will thermal throttle. Some Honeywell PTM 7950 is a good idea but even with the world's best thermal paste, the heatsink and fan are likely going to be inadequate to run this low power CPU at full speed indefinitely. The U series is specifically intended for short bursts of high speed followed by mediocre performance after that.

If you want your CPU not to run so hot then reduce the turbo power limits. Somewhere around 20W to 25W for PL1 and about 25W for PL2. I would reduce the turbo time limit to about 8 seconds. Check both Clamp boxes. I would check the MMIO Lock box and I would leave the Sync MMIO box clear. No need to sync when MMIO is locked. Instead of 100°C and constant thermal throttling you will probably have constant power limit throttling. That is more likely what Intel intended. Adjust the power limits however you like to get the right balance between performance and heat. The reality is that you will likely never be able to fully use the full performance that this CPU is capable of.