I unlock my first set of 4 pipes and when xp gets to the logon page it freezes, any ideas on why this is? I thought it could be lack of power I have an antec 330w in an athlon xp system but enabling the first 4 and disabling the 2nd 4 causes the same problem so Ive pretty much ruled that out. my 6800 has bios 5.40.02.12.51, enabling the vertex shader is not a problem and it works fine.