The write speed appears to be very low. The reads aren't very high either. You can get about the same throughput with an USB2 hard drive .. for comparison. However, if you're running this IQ instance in a virtual machine, make sure you have the vm client software installed.
IQ, any DBMS really, in a virtual machine environment will perform quite poorly compared to bare hardware. Virtualized IQ instances should only be for development and functional testing IMO. Virtualized IQ instances in production is just plain silly.
(note LPAR / containers are not virtual machines so this doesn't apply to them)
You may want to have your unix/storage admin do an i/o benchmark to determine if it is a storage (san/local disk/etc), controller or os issue. In any case, they need to be ruled out.
