From: Roland S. <rsc...@hi...> - 2005-01-24 17:12:11
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Felix K=FChling wrote: > I intend to improve the heuristics that chooses the texture heap in > driAllocateTexture. This may involve the texture size to allocate, the > heap sizes and the amount of free space on each heap and maybe the ages > of textures on each heap. I haven't thought too much about the details > yet. If anyone has already put some thought into this I'd appreciate > your input. IMHO, the ages of textures might be crucial to get a reasonable=20 heuristic. I'm not sure how much of a performance hit (especially with=20 agp 4x and the relatively slow savage chips) agp texturing has (if the=20 cards in question only have slow, narrow ram interfaces it might=20 actually even be faster), but I would think that in general it would be=20 beneficial to try local memory first, but if no recently-not-accessed=20 textures exist (though determining of the threshold what is recent=20 enough might involve some black magic), just use the agp gart heap=20 instead of throwing some local texture out. I don't think the other criteria you suggest (such as texture size in=20 relation to heap size) are really a good indicator where you'd want to=20 place the texture (ok for that just-fits-local-heap big texture you=20 might be better off usually with gart heap so all other textures fit=20 into local memory, but OTOH maybe it's the only texture currently really=20 accessed). Roland |