Richard yes, your loop does prove your fn to be a bit quicker. Weird how the run time of mine fluctuates so?!

Ho hum.

Good chatting.

Regards, Eddie.

I ran mine and Richard's functions on Jeffs test data (pushed up to 1000000 rows) and my function above (at 00:01:25.603) just pipped Richards (at 00:01:57.740).

alter table #HexTest add ASCIIValue...

Another function for the mix:

if objectproperty (object_id ('dbo.fn_HexToAlpha'), 'istablefunction') = 0 drop function dbo.fn_HexToAlpha

go

create function dbo.fn_HexToAlpha (@HexString char (40))

returns varchar (20) as

begin

declare @Loop tinyint, @AsciiString varchar (20), @Nibble1 char (1),...