CPU impact on battery

[carlito]

Hi,

is there a way for me to figure out the impact of CPU on battery life? I have a good budget for a laptop, but don't want to cripple the battery by over-specifying the CPU.

Are them some stats somewhere online about average battery drain or something like that?

The key processors to compare are:

• i7-4712MQ
• i7-4710MQ
• i7-4810MQ
• i7-4910MQ (probably too expensive)

I'm also interested in how the GPU affects battery. E.g. for the Cosmos II how much will battery life be affected by choosing the GTX850M over the GT840M?

Finally, do CPUs and GPUs use less power when they're not fully used? E.g. if the laptop is not being taxed or doing any 3D magic would all the CPUs/GPUs have similar drain or do some of them have higher "base line" power usage?

Please excuse my ignorance in these matters... there was a time in the past I might have known such things, but these days I'm just a pc user and not up to speed on the technical details!

Many thanks,


Carlito

 

[mantadog]

As far asd exact stats online, I don't know. But I do know the lower spec CPU's do use less power but within say the i3-i5-i7 family the difference would be minimal unless you take the bottom i7 vs the top i7 for example.

CPU's and GPU's do use as little power as they need at any given time, this has been a strong development point throughout the last few years. So getting a top spec i7 might be beneficial as it can crunch through work faster but use more battery in the process resulting in exactly the same workload as if you had just bought the lower spec i7 and it takes a bit longer to do the said work. if that makes sense....

 

[carlito]

Thanks, that's useful to know!

 

[Wozza63]

Majority of the time they will all consume pretty much the same power. It's only when they are being used a lot will the higher end CPUs use more power. They will all generally sit at the same level when idle or just general browsing and will only have 1 core turned on at that time at a lower speed. My laptop sits at 1.5GHz with just 1 core a lot of the time and it causes no hiccups because as soon as it needs more it will use another core or clock up.

Same with the GPUs, they will both be turned off when not in use consuming 0 power, and the 850M will use more power when in heavy use.

The i7-4710MQ + GTX 850M is a popular combo on the forums used by many including myself. I recommend this combo myself as the CPUs get a lot more expensive after this one and 840M is not really a gaming GPU.

I get a battery life better than I expected before purchase. It wasn't something I was too bothered about because the only reason I got a laptop was for easy transportation between two places where it gets used. But I've used it a couple times away from power and lasts a long time especially if you are doing something light like browsing or word processing.

 

[carlito]

Thanks for the reply, @Wozza356. Do you know roughly how long the battery life lasts with your spec? It looks similar to what I'm planning to get (although I would probably go with a single SSD only).

 

[SpyderTracks]

You can see my spec below and I know it's a different chassis, but I was also impressed at the battery life when using it for just general browsing and streaming. The new optimus technology is very effective and really does have an impact on overall battery usage.

 

[GeorgeHillier]

Thanks for the reply, @Wozza356. Do you know roughly how long the battery life lasts with your spec? It looks similar to what I'm planning to get (although I would probably go with a single SSD only).

I have the same spec (i7-4710mq and 850m) and the battery life is very much dependent on usage.

If I'm using it in a lecture for the internet and word it can last up to 4 hours on battery saver with brightness lowered, for gaming it will last up to 2 hours (depending what game, brightness etc).

The battery life is very good considering the specs, just make sure you use the nvidia control panel which will automatically switch between the integrated graphics and the nvidia gpu.