If you’ve used Oracle Cloud Infrastructure, you’ve probably come across the term OCPU when deploying virtual instances. Although the word vaguely hints at something, it isn’t entirely obvious. You may also wonder how an OCPU stacks up against a traditional vCPU or a physical core as measured by other cloud providers.
Without further ado, let’s demystify this conundrum!
Breaking down the term
An Oracle CPU (Oracle Central Processing Unit) or OCPU is Oracle’s way of measuring compute resources on their virtual instances. Most cloud providers tend to oversell their hosting resources, and hence, rely on customers to underutilize their systems to keep day-to-day operations running.
This isn’t the case with Oracle Cloud Infrastructure though, as an OCPU is an actual representation of the underlying physical CPU core and its associated symmetric multiprocessing (SMP) unit on a given server.
Essentially, this ensures that resources aren’t oversold and that you can safely rely on e.g. Oracle Database without having to worry about busy neighbours.
With Oracle you save over 50%, have performance and manageability SLAs that AWS doesn’t provide, and are running your workload on a cloud that expects, not fears, that you can fully utilize the resources you’ve purchased.
Dan Reger
Senior Manager, Product Marketing, OCI
How much exactly is an OCPU?
The aforementioned begs the question of how an OCPU measures in vCPUs. This isn’t too complicated to understand but it does depend on CPU architecture.
Take the newest generation of shapes, for example.
| Shape | Model | Architecture | OCPU | vCPUs |
|---|---|---|---|---|
| VM.Standard.E5.Flex | AMD | x86 | 1 | 2 |
| VM.Standard3.Flex | Intel | x86 | 1 | 2 |
| VM.Standard.A1.Flex | Ampere A1 | Arm (RISC) | 1 | 1 |
Essentially, x86 OCPUs are worth at least 2 vCPUs while Arm-based OCPUs are worth 1 vCPU – given their lack of associated SMP units.
The takeaway is that you’re getting more – or cheaper – reliable resources than initially anticipated, making Oracle Cloud Infrastructure a serious cost-effective alternative to the likes of AWS and Azure.
Summary
We learned that OCPUs are short for Oracle CPUs and that they help Oracle avoid overselling their physical resources. Not only are OCPUs reliable processing units, they’re also worth twice their equivalent in x86 vCPUs on both AMD and Intel shapes.
Thank you for reading. Let us know if you have any questions.