I agree w/ Archie. We have several CX50xx (Intel Atom CPU) and they work fine down to 1 ms cycle time. Below that, they start to show slight timing errors (we use CX20xx for < 1ms). I have used a CX80xx for 10 ms cycle time and wouldn't try pushing it faster. It seems more like a traditional PLC CPU. The CX90xx is in between the CX80xx and CX50xx in performance, so "might work". The CX50xx can run full Windows (instead of CE), which might be a big advantage.
If your company expects you to decide on paper, and order 10+, without first testing a prototype, they put you in a difficult position. That would be very poor management. If you can first try a prototype, I would buy a CX90xx for testing. If it doesn't have sufficient performance, you will surely find later tasks for it. Otherwise, you are best to buy qty xx CX50xx. Your company's product may cost more, but your personal career will be safer. Companies rarely appreciate the risk decisions employees are forced to make and that often don't align with the company's best interest. Some engineers drilling in the Gulf of Mexico were pushed to complete a well ($1M/day cost managers screamed), so they took a risk and rushed the job. Minimal risk for them, other than their day job, but cost the company billions when the rush caused a major incident.