Doubts about the PSP texture cache

diedel · Post by **diedel** » Thu Sep 25, 2008 1:17 am

Hi,
I have some doubts about texture cache:

1) What is the cache line size? 16x8 bytes?
2) A cache line contains a texture block?
3) For instance, when rastering a 512x512 texture, the GE rasters block by block (tiled rastering) or line by line but prefetching the texture blocks?
4) The above explains why slicing a big textures in 32 pixels width chunks it's better for cache hit rate? Because the GE caches always blocks? Why not 64 or 128?
5) The texture cache is fully associative?

I've read some interesting documents for that purpose but I think they are a little bit advanced for me yet:

http://www.cs.virginia.edu/~gfx/Courses ... Texturing/

Thanks in advance.

J.F. · Post by **J.F.** » Thu Sep 25, 2008 6:40 am

You should search for the info in the forum as there's already a thread covering it. The texture cache is a fixed size, so the number of pixels it will hold varies according to the format of the data.

diedel · Post by **diedel** » Thu Sep 25, 2008 7:03 am

I've been searching info in the forum, analyzed more or less the samples/blit.c and other big PSP applications, that's the reason I have so much doubts. I'll continue the searching :)

Thanks.