I've read a some articles on Table variable vs Temp Table performance and I have found them lacking good explaination. This one left me hanging at the end of the article http://www.sql-server-performance.com/articles/per/temp_tables_vs_variables_p1.aspx

Table 2: Using SQL Server 2005 (time in ms).

In some cases, SQL 2005 was much faster then SQL 2000 (marked with green). But in many cases, especially with huge amounts of data, procedures that used table variables took much longer (highlighted with red). In four cases, I even gave up waiting.

Why?