[sldev] Texture caching

[Laurent Laborde]

On 3/21/07, alissa_sabre at yahoo.co.jp <alissa_sabre at yahoo.co.jp> wrote:
>
> > However, each texture carries additional
> > system RAM and CPU overhead, so tracking tens of thousands of textures
> > is problematic in itself.

Some computer configuration will not see any improvment at all.
But some will see improvment !

The problem with secondlife is : Whatever the computer you may have
(eg: Octo-xeon with 16GB of ram and 4xNvidia 8800GTX 756Mb SLI), the
client won't run faster !
At least... before First Look.
Now with FirstLook we can see some good improvment with a better computer.
And that's good !

Think about user experience and frustration when, whatever you do,
Secondlife just run too slow, texture take age to load, fps are
insanly low for a "game", suck all you RAM and VRAM and cpu-cycle for
no acceptable reason...

Now tell them that :
- Secondlife is optimized for Octo-core cpu (and obviously run faster
with more thread and core)
- Secondlife can efficiently use your 8GB of RAM to improve texture
caching, store usefull data to improve user experience and speed
- using a cluster of squid proxy cache with 2 or 3TB of cache will
make your texture load instantly, will save your computer cpu cycle
because the texture are pre-dedoced on the cache (RLE or no decoding
at all), you don't have to download a lot of the texture anymore.
- add some dirty trick that will probably only run on the super-latest
gfx card but speed-up A LOT the FPS.
- ...

What will happen ?
Some crazy-techno-geeky-fanboy (like me?) will remove the dust on some
old unused computer and build a squid cluster.
They will buy more ram, better gfx card, octoCore cpu, etc ...
and WILL spread the word : "My SL run superfast because i'm an awesome
crazy super-nerdo and here is my setup".

That sound silly... but :
- You'll make a few techno-nerdo-geeky very happy. ;)
- It's user's fault, not LL. (since we will be able to say that it's
possible to run SL faster with a better computer. Actually not really
possible (ok, better with FirstLook now))
- Sooner or later we'll all have 8+GB or ram with
multi-multi-multi-core cpu (afaik the roadmap talk about cpu with
hundreds of core ...)
- You'll save some old computer from the trash and then save the world
by recycling billions of transistor. ;)
- blinking buzzword : SL is optimized for the future.

So, if you know a good optimization but it require 8 Core and 1TB of
fiber-optic disk... just do it anyway !

Secondlife still have his pool of super-techno-early-adopter.
Keep them (me) busy on something fun and new, before they (i) got
seriously bored and move to the 1st "lesser-Secondlife-clone" that
will come on the market. Lesser-secondlife but without bumping-newbie
looking for jobs and pixel-sex.
(Think about how many ppl moved to linux. Even if it wasn't sexy at
all, slow, buggy, and with no more capabilities than a broken GameBoy)

> Storing decoded texture with its compressed form on disk will add no
> RAM/CPU overhead.

Maybe storing them with RLE compression ?
afaik, the overhead for decoding RLE is insignifiant.
And considering the amount of "dumb" texture (with good ratio
compression with RLE) we're used to have in secondlife, it may save a
lot of spacedisk without degrading the speed.

-- 
Kerunix Flan