I just read about the burstable VMs and felt motivated to write about it in my personal blog.
As the name speaks, burstable VMs provides an opportunity to use a fraction of CPU with an ability to occasionally burst up to 100% of CPU but the highlight is that it costs you less than regular VMs. Hence you can run low-CPU workloads cost effectively on Oracle Cloud Infrastrusture(OCI) using burstable VMs.
While with flexible VM, we choose the no of CPU cores and memory to best suit the business workload. Here, we can use 100% of workload all the time thus ideal for workloads that consistently needs 100% of CPU core all the time. On the other side, when workloads needs small amount of CPU most of the time but occasionally need a higher amount of CPU, burstable VMs sounds more cost effective with an additional flexibility of choosing the fraction of CPU needed.
We can select OCPU between 1-64 cores, the memory between 1-64GB per core(up to a maximum of 768 GB), and the baseline OCPU utilisation as 12.5% or 50% of the total OCPUs. The baseline determines the minimum fraction of the CPU resources always available to the VM. A burstable VM with one OCPU and a 12.5% baseline can run at a sustained CPU performance of 12.5% of one core, or it can run lower than 12.5% and occasionally burst up to 100% of the core for short periods of time.
The beauty of burstable VMs is that they are charged at Oracle’s standard OCPU per hour price but only for the baseline OCPU chosen. This ensures that burstable VMs are much cheaper than non-burstable VMs. For a one-core, 12.5% baseline VM, you’re charged for 0.125 OCPU each hour, whether you use 12.5% or less of the CPU core or if you burst and use 100% of the core. Burstable VM’s flexibility and simple pricing make it a great choice to run your low CPU workloads.