Test for yourself, fire up similarly sized VPSs at both DigitalOcean and OVH and benchmark them running identical tests. The DigitalOcean VPSs are pretty fast but the OVH ones consistently perform better for both CPU and disk speed.
OVH supports startups just like the rest of the companies mentioned elsewhere in the thread too - see https://www.ovh.com/en/dlp/ for info. I have no affiliation with any of these companies except as a customer.