Performance and key lenght

<HTML> What is the speed difference on selects like select * from table where key = 'ksks......kjljf;qlfk"&nbsp; when the key on which selected is of size: <P>a) varchar[16] <BR>b) varchar[32] <BR>c) varchar[64] <P>The key is indexed so the select uses the index to find the table row(s). <P>Does it depens on the word size of the CPU and/or how many registers a CPU has. <BR>I am using a SUN Enterprise server with four UltraSparc II CPU's. <P>Regards, <P>Albert Wisse.</HTML>