Save battery life when possible.

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Posts 42
Doug Hiser | Forum Activity | Posted: Thu, Dec 29 2016 2:24 PM

I have a late 2016 MacBook Pro and have been doing some battery life tests that indicate that Logos eats battery like it was going out of style. The test I ran was to do a particular activity until I discharge the battery 5%. By timing this I can extrapolate the total battery time I should get if I only did this activity. Results:

  1. iBook Reading: 14-15 hours battery life.
  2. Logos Reading and note taking: little over 6 hours
  3. iBook Reading with Logos running in the background: approximately 7 hours

If you look at the Energy Tab in the Activity Monitor it shows that Logos Requires the High Performance GPU. It appears in this last test where iBook reading time was cut in half was related to Logos running in the background and forcing the system to use the High Performance GPU. My theory is that if Logos disabled this feature when you are operating off of batteries, then you could extend the battery life by 50 to 100%. This would be worth doing. Another approach is to give the user manual control of this in the Preference Pane. 

I have tried setting the Logos App to open in Low Resolution, but it still requires the High Performance GPU.

I currently quit Logos anytime I am not using it and if I plan on doing some heavy study away from the office or home, I pack a power adapter. 

I would add that it is likely that the new MBP's with integrated graphics is fast enough for Logos mobile operation. The new fast SDD's make Logos speedy for once. I love the speed but not lost of mobility.

Posts 4768
Fred Chapman | Forum Activity | Replied: Fri, Dec 30 2016 6:44 AM

I am no expert, but it seems to me that comparing the power usage of Logos and the iBooks reader is like comparing lawn mower to a semi-truck.

Posts 5213
SineNomine | Forum Activity | Replied: Fri, Dec 30 2016 7:58 AM


I am no expert, but it seems to me that comparing the power usage of Logos and the iBooks reader is like comparing lawn mower to a semi-truck.

If we go with that analogy, the lawnmower shouldn't be going through large amounts of gas while you're off reading a book.

Posts 856
Michael McLane | Forum Activity | Replied: Fri, Dec 30 2016 9:39 AM


I also have a 2016 MacBook Pro (with the best graphics option) and concur with all that you have stated. In my testing I left the computer idle without letting the display go to sleep while the display was set to 50% brightness and no apps running. In the battery lasted about 13 hours. I then did another test and the only thing different was that I had Logos running. I did not use the computer and Logos was not performing any actions I simply had one resource opened as if I were reading it. Everything else was completely idle. My battery life was reduced to about six and half hours. This was very disappointing as my primary use for the computer is for Logos.

The developers really need to take a look at this.

Posts 42
Doug Hiser | Forum Activity | Replied: Fri, Dec 30 2016 9:40 AM

I never said that Logos should have the same battery life as iBook, that is the reason I suggested that we should get at least a 50% increase in battery life by turning off the high performance GPU. If I had suggested what you are suggesting, I would have expected a 120% increase in battery life. My fault, I am a mathematician and the numbers told this part of the comparison that I forget that non-mathematician don't pick up on. I also thought that the third data point illustrates Logos consumes unnecessary power even when it is not being used. I really don't want Logos running in the background to cause my entire battery life to drop in half.

But let's run with your analogy, perhaps that well help non-technical people to understand. More specifically, let's look under the hood. We have in my MacBook Pro a modern engine that is actually quite powerful by its own. It also has a supercharged turbo add on that can boost the power for hills or when I am accelerating. This is  particularly useful if I hauling a heavy load. But a truck driver will tell you that they don't boost their power unless they need to, because someone has to pay for the gas it consumes. So the truck driver learns real quick when to engage the turbo and when it is not necessary. This is my point: Logos is not a heavy graphics load.

Technically, the high-performance GPU is needed if you are going to perform shading and real-time lighting effects. It is particularly needed if you are going to emulate fog, rain or smoke, but last time I checked Logos does none of these things. There is an integrated GPU built into the main processor that lets it handle things like displaying words on a page. You could actually compare iBooks to Logos in that much of the screen redraw is text and static pictures and thus should be fine with the low-end GPU because iBook does quite well with it. The GPU has nothing to do with handling the logic and databases and the things that differentiates Logos way above iBook.

I hope that brings us closer to understanding the issue. Merry Christmas.

Posts 15805
Forum MVP
Keep Smiling 4 Jesus :) | Forum Activity | Replied: Fri, Dec 30 2016 8:21 PM

Was Logos online or offline ?

Personally turn Wi-Fi off on a MacBook Air followed by opening Logos for offline use with more battery life.

Keep Smiling Smile

Posts 42
Doug Hiser | Forum Activity | Replied: Sat, Dec 31 2016 5:18 AM

WiFi was off. Cool

Posts 3444
Philana R. Crouch | Forum Activity | Replied: Tue, Jan 31 2017 12:31 PM
Hi Doug, We're looking into this, it will take some time to run some tests. Thank you for your feedback.
Posts 42
Doug Hiser | Forum Activity | Replied: Tue, Jan 31 2017 1:01 PM


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