Informix 5 and Informix 7 compatibility

Currently we are running OnLine Informix 5 on a Tandem and OnLine Informix 4.1 on a Sparc 10. We are considering upgrading the Sun to Informix 7. My problems are as follows: 1) The applications on the Sun sometimes need to access data on the Tandem DB. Can an OnLine 7 application "talk" to an OnLine 5.0 database ? 2) I have heard that despite many architectural improvements, OnLine 7 is primarily designed for multiprocessor systems and can actually degrade performance on a uniprocessor system (eg Sparc 10). Is this true ? Thanks in advance, Liam -- +------------------------------------------------------+ | . . | Liam Kenneally | | ... ... | email : kenneall@cork.cig.mot.com | | ..... ..... | phone : intl +353 +21 511381 | | .. ... .. | fax : intl +353 +21 357635 | | . . . | | +------------------------------------------------------+