When running video encoding the CPU on my legion 5 draws 45W, so I figured I could power my laptop with a 100W USB C wall plug. However when I plug it in the PC limits the CPU to 25W, even though the power draw is less than what the charger can supply. I've enabled rapid charging but with no luck. Any ideas?
Lenovo Legion 5 CPU Power Limit when using USB C PD
- Thread starter Fatpizza
- Start date
I'm not at all sure that the Legion 5 takes power through the USB C port. When I plug a 100W USB C PSU into my 5 Pro there is no indication on the battery icon in the notification area that there is external power available.
It definitely supports it through the rear USB C port. When I plug it in it comes up with a slow charge warning and the icon changes to show it's plugged in.
Soldato
Perhaps it’s limited to 45w or something then, rather than 90w or so
It may be worth checking that your USB cable can handle 100W as many are only rated 3A rather than the required 5A.
I've discovered that my 100W charger is useless and won't give the charging icon on the 5 Pro which the 90W charger from my Ideapad will so it's going back tomorrow.
I've discovered that my 100W charger is useless and won't give the charging icon on the 5 Pro which the 90W charger from my Ideapad will so it's going back tomorrow.
The cable I'm using came with the 100W Wall Charger and mentioned 100W capability on the box. Either way using the plug that shows power draw it is in fact power limited. I found a program called Ryzen Controller which seems to be an equivalent of Ryzen Master but for laptops. I can manually change the TDP and it works, however it goes back down again almost immediately so I would say this is a BIOS limitation.
This Ryzen Controller software has a setting to reapply the TDP settings at specified intervals, and I can reapply them every second. This seems to keep the CPU at a higher TDP and the power meter I have shows that it's drawing between 80-90W in total for the entire laptop so I can run this program during encoding and it works fine.
There is a consideration though that if it spikes to 100W the laptop immediately switches to a lower performance mode, where according to HWINFO64 the infinity fabric and the memory clock go down to 400Mhz. They can only be changed again by manually switching power profiles.
I'm going to turn the IGP back on (I've turned off Hybrid mode to always run on the 3060) and see if I can reduce the power consumption enough to where this isn't an issue.
This Ryzen Controller software has a setting to reapply the TDP settings at specified intervals, and I can reapply them every second. This seems to keep the CPU at a higher TDP and the power meter I have shows that it's drawing between 80-90W in total for the entire laptop so I can run this program during encoding and it works fine.
There is a consideration though that if it spikes to 100W the laptop immediately switches to a lower performance mode, where according to HWINFO64 the infinity fabric and the memory clock go down to 400Mhz. They can only be changed again by manually switching power profiles.
I'm going to turn the IGP back on (I've turned off Hybrid mode to always run on the 3060) and see if I can reduce the power consumption enough to where this isn't an issue.
Soldato
Isnt the opriginal charger 170w? Stands to reason that the laptop would try to throttle if you cut the available current by 40%.