Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_18950885_3 ( used__kb_ INTEGER, graphics_mode VARCHAR )

### Question ###
What is the used (kb) when the graphics mode is 4?

### Accurate SQL ###

SELECT MIN(used__kb_) FROM table_18950885_3 WHERE graphics_mode = 4