Stack Overflow
Stack Overflow

Questions tagged [energy]

Question regarding energy consumption of hardware of different instruments such as cpu's, cell-phones etc.

Question regarding energy consumption of hardware of different devices such as cpu's, cell-phones etc. Related tags are , .

237 questions
46
votes
13 answers

PHP vs. Java are there energy consumption differences?

I heard a rumor, that Java consumes less energy than PHP and was wondering if and how this would be true. I'm currently working in a company where we base most of our apps on PHP. Power consumption has never been the problem for us, but we are…
Thomaschaaf
  • 17,847
  • 32
  • 94
  • 128
32
votes
3 answers

Decoding the CLLocationAccuracy const's

the following are listed in CLLocation.h but from my experience they are deceiving names- possibly originally thought up to serve two purposes, 1. to test the accuracy of the location returned, but also 2. to set how hard the location manager works,…
dave
  • 883
  • 3
  • 11
  • 13
31
votes
2 answers

Xcode7 what is "Overhead" for energy profiling gauge?

I'm checking the energy profiling of an app that loads a lot of content into web view. I'm greeted with the following gauge. I see that the energy impact is high, and there's a consistently high overhead (54% in the screenshot). What is the meaning…
Alex Stone
  • 46,408
  • 55
  • 231
  • 407
28
votes
14 answers

What is "energy" in image processing?

I've read across several Image Processing books and websites, but I'm still not sure the true definition of the term "energy" in Image Processing. I've found several definition, but sometimes they just don't match. When we say "energy" in Image…
Karl
  • 5,613
  • 13
  • 73
  • 107
26
votes
6 answers

Re-assign/override hotkey (Win + L) to lock windows

Is it possible to re-assign the Win+L hotkey to another executable/shortcut? Use-case - I would like to switch off the monitor of my laptop as soon as it is locked. I know of a executable which can lock and turn off the monitor but I do not want to…
Mohit
  • 652
  • 2
  • 8
  • 8
18
votes
4 answers

Does anyone know any Compiler which optimizes code for energy consumption for embedded devices?

It's a general view that a faster code will consume less power because you can put CPU in idle state for more time but when we talk about energy consumption, is following a possibility: Suppose there's a instruction sequence which gets executed in…
Abhishek Mathur
  • 181
  • 3
17
votes
3 answers

Do sse instructions consume more power/energy?

Very simple question, probably difficult answer: Does using SSE instructions for example for parallel sum/min/max/average operations consume more power than doing any other instructions (e.g. a single sum)? For example, on Wikipedia I couldn't find…
Antonio
  • 19,451
  • 13
  • 99
  • 197
16
votes
7 answers

Energy consumption of smartphone components

I'm looking for a list of all the components and their power drainage on an up-to-date smart phone. Accelerometer, gyroscope, magnetometer, etc. Display WiFi Bluetooth GPS CPU Camera Microphone etc. Preferably in mA so it can be easily compared to…
eL.
  • 311
  • 1
  • 2
  • 15
13
votes
2 answers

why does a conditional variable fix our power consumption?

We were working on our audio player project on mac and noticed that the power usage was so high (about 7x that of google chrome doing the same workload.) I used xcode's energy profiling tool, one of the problems was we had too much cpu-wake…
Bill Yan
  • 3,369
  • 4
  • 27
  • 42
11
votes
8 answers

Algorithm to calculate the most energy efficient ad-hoc network

I have a (theoretical) network with N nodes, each with their own fixed location. Each node sends one message per cycle, which needs to reach the root either directly or via other nodes. The energy cost of sending a message from node A to node B is…
Meir
  • 12,285
  • 19
  • 58
  • 70
10
votes
3 answers

Instruments doesn't show Energy Usage Level: it is empty

I have followed the Apple steps to get my app energy usage level from my device using Energy Diagnostics Instruments…
angeleke
  • 219
  • 2
  • 10
10
votes
2 answers

perf power consumption measure: How does it work?

I noticed that perf list now has the option to measure power consumption. You can use it as follows: $ perf stat -e power/energy-cores/ ./a.out Performance counter stats for 'system wide': 8.55 Joules power/energy-cores/ …
user14717
  • 4,757
  • 2
  • 44
  • 68
8
votes
1 answer

Create a 128Bit UUID with String

I tried to create a 128Bit with the iOS CoreBluetooth framework. The code that I have written is here: //16Bit Value-String static NSString * const ADVERTISING_SERVICE_16=@"FFC0"; //Var for 128Bit String static NSString *…
nivek
  • 151
  • 2
  • 7
7
votes
2 answers

Energy efficient GPS tracking

I am making an application that requires user to send their GPS location to the server. I need it to be done for say every 10 seconds, which is heavy on the energy budget. Is there any open source implementation, where I can take GPS location once…
Prashant Tiwari
  • 99
  • 1
  • 9
6
votes
1 answer

Energy consumption per x86 instruction?

I am aware of a few tools that measure power consumption of programs, such as powerTOP, RAPL and the like. However, I was wondering if there exists some kind of benchmark such as Agner Fog's benchmark of CPU's…
JOKKINATOR
  • 356
  • 1
  • 11
1
2 3
…
15 16