[sldev] Cache speed experiment & results...

[Robin Cornelius]

>
> The result? Even after loading everything in the sim into the cache, tping
> between two locations (in the same sim, but outside of draw distance from
> each other) resulted in ZERO perceptible texture loading speedup. Loading
> from the RAMDisk was as slow as loading from regular disk. I presume,
> therefor, that the real bottleneck in the cache isn't reading from the
> drive. This is horribly dismaying. What progress is there toward an improved
> caching mechanism? Is there a way to store the textures in a decoded,
> ready-to-use fashion? Why is the cache so slow?
>

Are you *sure* all textures are indeed being loaded from the cache and
not being requested from the servers. I noticed some excessively large
texture downloading when doing textures tests and i would have
expected many of them to be in the cache but they were not (or may be
they had just been culled/purged). I didn't do a lot of testing
specifically in this area but the texture console can help also adding
debug lines to lltexturefetch.cpp is probably a good check too to see
which textures take which path.

Robin