Path: chuka.playstation.co.uk!scea!peter_alau@playstation.sony.com From: pbureau@colba.net (Patrick Bureau) Newsgroups: scee.yaroze.programming.2d_graphics Subject: Re: Caches Date: Sat, 15 Aug 1998 06:18:14 GMT Organization: SCEA News Server Lines: 31 Message-ID: <35d51fb9.8182565@news.scea.sony.com> References: <35C81A30.4ACB@club-internet.fr> <35C82DDB.3E12E37C@scee.sony.co.uk> <01bdc061$2c186980$f30b0a0a@Angela1.intelligent-group.com> <35D2E01D.5CA1@mdx.ac.uk> <6r0vps$n7i6@chuka.playstation.co.uk> <35D43404.282A@mdx.ac.uk> <35D438D2.908C3316@ndirect.co.uk> <35D43F08.36BA@mdx.ac.uk> <35D44CBE.1FA95769@ndirect.co.uk> <35D46843.5DF5@mdx.ac.uk> <35D4750C.A4613436@ndirect.co.uk> <35D47AA8.4E80@mdx.ac.uk> <35D48242.CC86BE26@ndirect.co.uk> NNTP-Posting-Host: a68.Dynamic-IP.Mlink.NET X-Newsreader: Forte Free Agent 1.1/32.230 On Fri, 14 Aug 1998 19:30:26 +0000, Alex Herbert wrote: >Anyway, using the D-cache will up the speed of GsSortObject4() regardless of the TMD size. >Where have you located the scrtachpad at the moment? It's very normal to locate the >scratchpad in the D-cache. Are you sure it's not there already? If not, then you should >see a huge increase in performance by putting it there. > >Herbs > Hi! I just looked at the GsSortObject4() definition in the library reference book and here what it says: "scratch is used as work when automatic subdivision is carried out....Also, scratchpad is cache memory and 256 words are packaged from 0x1f800000." And I noticed something quite interesting last week when I was playing with the automatic subdivision flag. I've got a big 8-bit 256x256 rectangular poly among other things in my scene. Here's the results by applying the GsDiv flag on the rectangular poly: Division amount Frame rate(in hsync) None 215 1:2x2 212 2:4x4 198 3:8x8 181 4:16x16 191 5:32x32 270 You can see that the biggest improvement in performance was by doing 8x8 subdivisions! I couldn't believe it! But I must say that after reading the GsSortObject4() definition it makes more sense :) Patrick Bureau