mobile deviceperfoptimization jtpa_release

Mobile 機器のパフォーマンス最適化

Hakuro Matsuda@hak / hakuroum@gmail.com

Saturday, July 26, 14

最適化のゴール• Better UX

• Smooth animation

• 60FPS の達成

• Quicker response time

• Longer Battery life

• (Richer contents)

Saturday, July 26, 14

Know your HWCPU/GPU: Cortex-A15 相当 2~4 コア + モバイル GPU

• 100~300 GFLOPS

RAM:1GB~3GB• LPDDR3/DDR3L 帯域 6.4GB/s~17GB/s

Screen: 1080p~WQXGA(2560x1600)• 240~480dpi

Battery: 2000~3500mAhLTE:

•下り~326Mbps　上り~86Mbps

•実効 ~60Mbps　レイテンシ ~100msec

Saturday, July 26, 14

バッテリー消費• Radio

• LCD

• CPU/GPU

Suspended State (68 mW)

Video Playback (450 mW + backlight)

Android G1 energy consumption “An Analysis of Power Consumption in a Smartphone”, USENIX 2010

Saturday, July 26, 14

Variable CPU Cycles

• 可変クロックレート

• CPU governor

• Thermal Throttling

• CPU load throttling

• 300 Mhz ~2.3 Ghz (N5) http://arstechnica.com/gadgets/2013/11/when-benchmarks-arent-enough-cpu-performance-in-the-nexus-5/

Saturday, July 26, 14

Demo: CPU throttling

Saturday, July 26, 14

Mobile Network

• 送らない

• Push通知

• ~128Byte以下

• Bulkで送る

A Close Examination of Performance and PowerCharacteristics of 4G LTE Networks

Saturday, July 26, 14

まとめ• 携帯電話機の HW 特性について

• Android NDK を使った Low level 最適化について(追加テスト中で資料略)

• C++11 rocks!!

Saturday, July 26, 14