Source
r/GamingLaptops•
Jrix

Why is battery life in gaming laptops so bad when not playing games?

Even those with 70+ watt hour batteries are bad.

Nvidia is a company focused exclusively on graphics processors, and yet their efficiency can't beat intel?

Not even including that though; when fiddling with all the dials: forcing integrated graphics, lowering brightness, lowering hertz, turning off lights, reducing CPU/GPU wattage to tablet levels - battery life doesn't remotely approach a typical 50WH productivity laptop.

Does anyone know what's going on? This doesn't seem like a tradeoff that should have to be made.

Posted Jul 25, 2019, 9:28 PM UTC

214
mackie__mAW15R3 4K/HP Spectre 4K OLED•

When you say productivity laptops notice that most of them will use a U version processor. These are good at less work and more battery. Good for word, etc.

If you're doing heavy duty work, ie gaming, code compilation, 3d etc this is going to suck for you. They can't perform as well as the H, HQ or other high performing variants.

This is one reason and trade off as to why the battery sucks. There are hacks for this that makes this better such as undervolting, battery saver mode, etc.

The other obvious one is the GPU. Notice that the productivity laptops use low power GPUs if they use a discrete one.

As you see there is no free lunch. It's always a trade off.

3
drakanx•

productivity laptops are using components that draw a lot less power than those found in gaming laptops.

2
JrixOP•

That's my kneejerk reaction as well, but that has no explanatory power. What components? Are beefy VRM's intrinsically inefficient?

1
drakanx•

for one, the CPU. Productivity laptops use Intel U processors which have a 15W TDP vs. gaming laptops that use H processors with a 45W TDP.

2
japzone•

Most productivity/casual laptops don't have a discrete GPU for one. That saves a lot of power right there, though Optimus is supposed to compensate for that. Then you have high performance versions of the CPU in gaming laptops. They're designed to prioritize high clocks and eat up much more power on average, which means even when doing light tasks they'd be wasting more energy than the power efficient models because there's a limit to how much you can dynamically throttle in a complex Windows PC environment. Then there's the active cooling, which OEMs tend to design to be more aggressive in gaming laptops in order to combat the higher temps that gaming laptops reach on average, which hence uses more power. Also, high refresh rate displays will eat more power on average since Windows will use the set framerate at all times, as it has no dynamic framerate scaling for the desktop.

Those are the major power consumers. Doesn't seem like much, but they can make a big difference.

1
pssiraj•

That's not exactly right. I can get over 7 hours consistently with my Triton 500 (84Wh) with an undervolt, not even full battery saving. If you're not getting that, something is keeping your GPU on or you don't have Optimus as an option.

1
JrixOP•

LG Gram: 72Wh Lithium Battery (up to 19.5 hours)

What is it doing different that's so much more efficient?

1
pssiraj•

Okay, first off no laptop that I know of is going to get up to 19.5 hours without turning off WiFi and everything, brightness on 0, etc and maybe only using Notepad or something. My device has Optimus, and the RTX 2060 is almost always inactive unless I game. If the 2060 was active, I might get 3 hours if I'm lucky. That's the point of Optimus: it can turn off the dedicated GPU when you don't need it.

1
mackie__mAW15R3 4K/HP Spectre 4K OLED•

Triton 500 uses max q right?

1
pssiraj•

I have the 2060 non MaxQ. The 2070 and 2080 models are MaxQ.

1
mackie__mAW15R3 4K/HP Spectre 4K OLED•

Hmmm. Essentially that performs worse than 1070 mobile, right? In terms of fps you can get. Sure you save power and it's slim, again it's a trade off. I'm sure you can't watch YouTube with full brightness for even 3 hours right?

1
pssiraj•

The Triton has a very bright screen, I wouldn't want to. I have run multiple sessions of Google Docs for 6-7 hours so I suspect YouTube would last about that long. That's not intensive enough to turn on the GPU.

As far as the 1070, I think the 2060 is a little worse currently, you trade off some fps for Ray Tracing in the future.

1