> Compression is done on the server, and (hopefully) once per unique response, which is then cached.
Only works for low-dynamicity response. Or fully static assets.
> Decompression is fast.
I quoted numbers. LZMA decompression takes twice as much CPU time as gzip in the best case.
> I don't think memory is an issue when we're talking about decompressing some HTML/CSS/Javascript
Memory is not a function of payload size in compression algorithms, it's a function of compression parameters. xz -9 will have ~65MB of memory overhead regardless of the payload size (and LZMA is flexible enough that you can craft a single payload requiring gigabytes of working memory, xz's man even warns about it).
> CPU is barely an issue, considering how powerful modern mobile devices
CPU transitions are extremely aggressive on mobiles. The more CPU time has to be spent decompressing payloads the less the CPU can be in deep hibernation state and the more battery you burn through.
Not a tradeoff which makes much sense considering >3G bottlenecks tend to be latency and processing more than bandwidth for "basic" HTML/CSS/JS web content (and really most things outside of video streaming)
> New phones seem to have as much power and as much RAM as my 5 year old PC.
Phones usually can't page out, and aren't tethered to a wall.
Also depends which "new phones" you're looking at, the Firefox OS-based ZTE Open has 256MB RAM and a 1GHz single-core Cortex A5.
Only works for low-dynamicity response. Or fully static assets.
> Decompression is fast.
I quoted numbers. LZMA decompression takes twice as much CPU time as gzip in the best case.
> I don't think memory is an issue when we're talking about decompressing some HTML/CSS/Javascript
Memory is not a function of payload size in compression algorithms, it's a function of compression parameters. xz -9 will have ~65MB of memory overhead regardless of the payload size (and LZMA is flexible enough that you can craft a single payload requiring gigabytes of working memory, xz's man even warns about it).
> CPU is barely an issue, considering how powerful modern mobile devices
CPU transitions are extremely aggressive on mobiles. The more CPU time has to be spent decompressing payloads the less the CPU can be in deep hibernation state and the more battery you burn through.
Not a tradeoff which makes much sense considering >3G bottlenecks tend to be latency and processing more than bandwidth for "basic" HTML/CSS/JS web content (and really most things outside of video streaming)
> New phones seem to have as much power and as much RAM as my 5 year old PC.
Phones usually can't page out, and aren't tethered to a wall.
Also depends which "new phones" you're looking at, the Firefox OS-based ZTE Open has 256MB RAM and a 1GHz single-core Cortex A5.