Question Laptop CPU clock dropping to 800mhz during load on battery ?

[starkiller.lollo]

Hello everyone!

I've been looking around everywhere for this issue and nobody seems to have my exact same problem, so no useful solutions so far. I bought an Asus vivobook pro n580vn this summer, it runs on a 7700hq and it does so great generally. Except if I'm working on battery!

This is the context:
I'm in high performance mode in windows, and I mean all-out high performance manual settings (min-max clock at 100% etc.), so the cpu is at a variable 3.4-3.7ghz but no less. As soon as it starts draining a certain amount of power though it drops down to constant 800mhz. Temps are fine, I even properly replaced the thermal paste with noctua's nt-h1 (we're talking 90-95C during AIDA64 stress test on AC power: no thermal throttling once the fan reaches max RPMs, clock around 2.9-3Ghz which is higher than the stock 2.8 so no problem there)

I noticed this on my framerates in games, even old ones like SW Kotor (but who cares, could be also related to graphics, so tough: i'll run my games on AC). The problem is that it behaves the same way when using evne just cpu related programs, such as Cubase or other DAWs. I'm a composer, imagine needing to show a working project to a client while on battery power and not being able to use the whole potential of my laptop, it sucks big time!

Somebody wrote in another forum that these issues were caused by the battery not being able to supply as much power as needed, but I should think that this would cause a proportionate clock speed drop based on how much power it's actually being drawn, not solid 800mhz across the board. I think I should be able to use full power for some glorious 30 minutes if I chose to, rather than have my pc decide to save power and last longer regardless.

My question is: does anybody have a software solution? Do you think it's something wrong in the bios p-states (version 308 btw, the latest as I'm writing this) and Asus should fix it? Keep in mind that bios options are practically nonexistent, especially power and clock related ones.

Thanks to anyone that has a clue to what's happening and possibly how to fix it!

 

[izoli]

My asus with 7700hq does same thing on battery, doesnt affect me much though. Itll always be clocked lower while on battery, but yeah I agree under 1Ghz is pretty crazy.

I even went with liquid metal on the cpu to reduce temps which helped immensely(from 90c to 65c) but have the same power limitations on battery.

I might try some stuff out this evening, but if there is a known solution I may be interested in trying also.

 

[starkiller.lollo]

Thanks for the reply, I believe many users experience this and that it's a problem with the power management at bios level. It's not so much about the clock being generally lower on battery though as much as it dropping to minimum. It will stay at full boost clock even without AC if I tell the computer to do so. Trouble is on AC it will keep staying like that under load, on battery it will systematically go down to 800mhz, no exception, no fluctuation, until the load decreases to a certain amount (a fixed level, not one proportional to activity) or goes idle. Then the cpu will happily get back to 3.4ghz and up, as soon as i no longer need it to be that high ironically! So in daily use it behaves normally (web browsing, hd video streaming etc), but as soon as I use the machine to do actual work it's useless on battery.

 

[starkiller.lollo]

I know it's been years but I post this solution to anyone who might have the same issue possibly on other systems as well. So basically in my laptop the battery only delivers 47W of power and for some reason the system is setup to be EXTREMELY conservative so that as soon as the cpu needs a fraction of that (can't remember exactly how much but very low) it misuses the BD PROCHOT flag to throttle down on power to 28% cpu utilization (not thermal throttling, it's not actually overheating at all, we're talking 40-50 °C).

Using ThrottleStop I was able to unflag the BD PROCHOT, disable turbo on battery profile and optimize Speed shift to 2.5Ghz so that the whole system draws around 42-46W under extremely heavy load (prime95 blend stress test). It's not perfect, takes into account only heavy cpu and ram use, not gpu use... but on the other hand a real-world scenario where gpu is used won't be as heavy on the other 2 components so it should be fine.

Only drawback is that I need to have throttlestop on autostart and have it switch between the "nerfed" profile for battery and normal for AC power, which sometimes causes the program to crash when plugging and unplugging the cord. At least now the pc is very usable with just a reasonably small amount of perfomance lost on battery. Can moderately handle some gaming as well