Hi,
If you are asking about OpenVZ VPS providers then they MAY offer burstable CPU as a fair-usage or fair-share policy. But that burstable CPU may last for a minute or two.
If you abuse it often then they'll ask you to upgrade to KVM VPS or Cloud VPS where you get ample dedicated CPU and should be worried about burstable CPU.
Always remember, Dedicated CPU is real CPU core than the vCPU core which is virtual or thread of a CPU. Get a VPS with dedicated CPU, a self-managed or managed KVM VPS hosting from
The-Online.com - they are quite reliable and reasonable provider in VPS market.