Hi, Hans and Jonathan: I made some testing samples in ConTeXt to test XeTeX. but the result is quite strange. All benchmark are get from the second run: Sample 1: \definefont[a][file:SimSun] \starttext \dorecurse{10000}{ hello {\a 你好}} \stoptext And here is the result: XeTeX: TeXExec | runtime: 7.25 LuaTeX: MTXrun | total runtime: 6.719 This is considerablly ok. So we can say that the font switching is pretty fast. Sample 2: \definefont[a][file:AdobeSongStd-Light.otf] \starttext \dorecurse{10000}{ hello {\a 你好}} \stoptext XeTeX: TeXExec | runtime: 63.65 LuaTeX: MTXrun | total runtime: 8.156 Here I only change the font from SimSun to Adobe Song (the two fonts are almost at the same sice [~10M]). But the xetex result is very differt from the previous run. it consumes one minute to compile the file. Sample 3: \starttypescript[serif] [myzhfont] \definefontsynonym [Serif] [file:SimSun] \definefontsynonym [SerifBold] [file:SimSun] \definefontsynonym [SerifItalic] [file:SimSun] \definefontsynonym [SerifBoldItalic] [file:SimSun] \stoptypescript \starttypescript[sans] [myzhfont] \definefontsynonym [Sans] [file:SimSun] \definefontsynonym [SansBold] [file:SimSun] \definefontsynonym [SansItalic] [file:SimSun] \definefontsynonym [SansBoldItalic] [file:SimSun] \stoptypescript \starttypescript[mono] [myzhfont] \definefontsynonym [Mono] [file:SimSun] \definefontsynonym [MonoBold] [file:SimSun] \definefontsynonym [MonoItalic] [file:SimSun] \definefontsynonym [MonoBoldItalic] [file:SimSun] \stoptypescript \definetypeface [myzhfont] [rm] [serif][myzhfont] [default] \definetypeface [myzhfont] [ss] [sans] [myzhfont] [default] \definetypeface [myzhfont] [tt] [mono] [myzhfont] [default] \def\a{\myzhfont} \starttext \dorecurse{10000}{ hello {\a 你好}} \stoptext XeTeX: TeXExec | runtime: 64.797 LuaTeX: MTXrun | total runtime: 10.797 Here we use SimSun since in the first sample xetex can load simsun quite fast. However, in this time we define a typescript, and make all the styles fall into SimSun. Now xetex behaves quite strangely: it uses one minutes to compile this single document... So my question is - why loading otf is so slow? - is this a bug in context or in xetex? can it be fixed? - how can we make sample 3 (using typescript) run faster? Thanks. Yue Wang