7/25/2016

Oodle 2.3.0 ARM Report

I prepared a detailed report of Oodle's performance on ARM mobile devices (Android and iOS).

The full report is here :

oodle_arm_report on cbloom.com

It's a thorough test on many devices and several corpora. See the full details there.

Cliff notes is : Oodle's great on ARM.

For example on the iPadAir2 64-bit , on Silesia :

We found that the iOS devices are generally very good and easy to program for. They're more like desktop Intel chips; they don't have any terrible performance cliffs. The Android ARM devices we tested on were rather more difficult. For one thing they have horrible thermal saturation problems that makes testing on them very difficult. They also have some odd performance quirks.

I'm sure we could get a lot more speed on ARM, but it's rather nasty to optimize for. For one thing the thermal problems mean that iterating and getting good numbers is a huge pain. It's hard to tell if a change helped or not. For another, there's a wide variety of devices and it's hard to tell which to optimize for, and they have different performance shortfalls. So there's definitely a lot left on the table here.

Mermaid & Selkie are quite special on ARM. Many of these devices have small caches (as small as 512k L2) and very slow main memory (slow wrst latency; they often have huge bandwidth, but latency is what I need). Mermaid & Selkie are able to use unbounded windows for LZ without suffering a huge speed hit, due to the unique way they are structured. Kraken doesn't have the same magic trick so it benefits from a limited window, as demonstrated in the report.

See the index of this series of posts for more information : Introducing Oodle Mermaid and Selkie .
For more about Oodle visit RAD Game Tools

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