Here is my code:

{
db.setConnection(new com.borland.dx.sql.dataset.ConnectionDescriptor(
// "jdbc:firebirdsql:trans/3050:/dbs/blobtest.gdb", "sysdba", "xxx",
false, "org.firebirdsql.jdbc.FBDriver"));
"jdbc:interbase://trans//dbs/blobtest.gdb", "sysdba", "xxx", false,
"interbase.interclient.Driver"));

db.setDatabaseName("");

db.setTransactionIsolation(java.sql.Connection.TRANSACTION_REPEATABLE_READ);
db.setAutoCommit(false);

try {
db.start();
FileInputStream img = new FileInputStream("c:/test.gif");

PreparedStatement statement = db.createPreparedStatement("update test
set blob_data = ? where id = 1");
statement.setBinaryStream(1, img, img.available());
statement.execute();
db.commit();
}
catch (Exception ex) {
ex.printStackTrace();
}
}

I don't have a 100 MBit/s link to the server it will come down to a max of
about 4 MBits/sec and I would be happy with something like 35 sec but 9.5
Min is not tolerable

Your wire throughput is about 30 MBits/sec.

Have you tried the same with the firebirdsxl driver?

Herbert