AMD 7840U 5+ W Idle CPU Power Draw on Windows 10

I’ve been tracking the CPU package power in HWiNFO64 and I can’t get it to drop below 5 W when idle (with browser tabs and Word documents open), and it’s averaging closer to 6 or 7 W. I am running Windows 10 and have USB-C for the rear 2 ports and USB-A in the front two ports.

I hoped for better battery life and it does seem a bit better than the i5-1135G7 I upgraded from, but not nearly as good as I had hoped.

Is this level of power consumption normal? I can’t see how all the reviews are claiming 8 or more hours of battery life.


I’m not sure which is accurate but I’m getting conflicting numbers from HWinfo vs HWmonitor. The latter shows power dropping to around 2W when idle, but I see the same behavior as you in HWinfo.


I’m seeing the same thing on Windows 11. The package power in HWiNFO64 is definitely wrong because the battery discharge rate is sometimes lower than the reported CPU package power, which is definitely impossible. The GPU power measurements in HWiNFO64 are clearly also borked since they only show integer watts of power draw.

That said, the battery discharge rate should still be accurate, and that still shows a power consumption that rarely goes below 5 W and never below 4 W. This is in contrast to my old i7-1165G7, which at idle could go as low as 3 W sometimes (though obviously it was usually higher under even light loads).

I suspect there’s something broken in AMD’s firmware for this chip since I’ve seen similar reports from people with other 7840U laptops regarding idle power draw. I hope it does get resolved at some point through updates because battery life was one of my reasons for upgrading to this board.

That is interesting. The estimated attery life on my device (which I haven’t used unplugged very much so far) is just under 6 hours, which suggests an idle power draw of around 8 W.

I think Windows battery life estimate is borked right now. I get wild swings from 6 hours to 10 or 12.

That’s a little better than what I’m getting at idle on my Elementary OS (Ubuntu) installation, although I have the 7640. I’ll get around 6 hours of battery life. Hoping we see some efficiency gains in the future. Battery life is pretty lacking from what I was hoping for.

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I noticed in Task Manager that the GPU sits at around 10% or more GPU utilisation when idle. That does not seem right and might explain the high idle power consumption.

Monitoring software may keep your GPU awake, increasing the power draw. A good alternative is to use the ectool and check only the battery discharging wattage