Solaris: temporary tables in /tmp VS in a temporary dbspace

Hi Gurus out there! Using IDS 10 on Sun Solaris 10. I have a question about Informix performance when using a dedicated temporary dbspace (properly setup and declared in DBSPACETEMP in onconfig) versus using the default location of temporary tables ('/tmp', which on Solaris is a memory based file system). This IBM page http://publib.boulder.ibm.com/infocenter/idshelp/v10/topic/com.ibm.sqlr.doc/sqlrmst193.htm says the following: 1) The dbspaces that you list in DBSPACETEMP must be composed of chunks that are allocated as raw UNIX devices. 2) order of precedence for where to create temporary tables: # The dbspace or dbspaces that the environment variable DBSPACETEMP specifies, if this is set # The dbspace or dbspaces that the ONCONFIG parameter DBSPACETEMP specifies. # The dbspace or dbspaces that the ONCONFIG parameter TABLESPACE specifies. # The operating-system file space in /tmp (UNIX) or %temp% (Windows) Am I right in interpreting that using DBSPACETEMP is to be preferred over /tmp? If so, why, beside the fact that using '/tmp' on Solaris means eating memory? Is there anyone that has done a performance benchmark using DBSPACETEMP versus '/tmp' on Sun Solaris? Thank you in advance Rupan3rd (from Italy - and no, it's not sunny)