Intersolv ODBC Drivers - Performance on Solaris

I used an intersolv ODBC driver on Solaris 2.5 to connect to an informix v7 database. I also used an informix native ODBC driver on the same platform to connect to the same database. I noticed that the intersolv drivers performed really well on small datasets. However on larger datasets performance of intersolv drivers degraded drastically. Here is an example: Query used select * from "table_name" DRIVER Informix Driver - libifmx07.so.1 ------------------------------------------------------------------- DATABASE ROWS FIELDS SIZE(k) CPU TIME(s) K/sec -------------------------------------------------------------------- Sample 60175 16 7343 89 82.50 DRIVER Intersolv Informix Driver - qeinf708.so -------------------------------------------------------------------- DATABASE ROWS FIELDS SIZE(k) CPU TIME(s) K/sec -------------------------------------------------------------------- Sample 60175 16 7343 4284 1.71 Has anybody used intersolv drivers on Unix (both the client & server reside on Unix) experienced similar problems or am I doing something wrong somewhere?