[sldev] Asset Optimizations

[Ambrosia]

On Fri, Oct 23, 2009 at 12:12, Stickman <stickman at gmail.com> wrote:
> Is it possible to see the "size" of an asset? Size may exist in
> various forms, such as "in memory" size, "on disk" size, and
> "bandwidth used." Are textures stored in memory in a compressed state,
> or do they have a a byte per pixel?

Naturally they are (to my knowledge) compressed in normal Ram, but when it
comes to graphics cards, textures need to be completely uncompressed
in their memory.

> What assets are cached? I thought everything was cached, but I heard
> on the list recently that actual prim/object data was not cached, just
> their textures. Are animations cached, or do they have to load the
> first time they're seen that session?

To my knowledge, everything is cached, however some files that get created
when the cached data is uncompressed into special file formats (.lso, .dsf)
get removed again after the session. Some third party viewers allow a debug
setting so the uncompressed files remain in cache after a logoff, solving
some issues especially when it comes to multiple logins, however
keeping uncompressed sounds can blow the cache size to lots of gigabytes
since the uncompressed sound data is pretty much wav format.

> What's the "seek time" for the cache, as well? Is it pretty much as
> fast as disk access to load an asset, or are there a number of hoops
> that must be jumped through? Is any part of the cache held in RAM, or
> is it on-disk unless the asset is currently shown inworld?

I think it depends on the asset type, but to my knowledge textures get
unloaded again
mere seconds after they have not been seen in-world.

> Thanks,
>
> Stickman
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