The cost of running a single Oracle Cloud Infrastructure (OCI) virtual machine instance is determined by its specific configuration. This includes the compute shape (size, which dictates OCPUs and memory), the region where it is deployed, and any associated software licensing for the operating system (e.g., Windows Server). The number of other virtual machines running in the tenancy affects the total overall bill, but it does not change the individual hourly or per-second rate of a specific, single VM instance. The unit cost for one VM is independent of the quantity of other VMs.

A. The size of the VM instance: The VM shape, or size (e.g., VM.Standard2.4), directly determines the number of OCPUs and amount of memory, which are primary components of the instance's price.
B. The operating system used by the VM instance: While Oracle Linux is included at no extra cost, using licensed operating systems like Windows Server or Red Hat Enterprise Linux incurs an additional charge, directly impacting the instance's total cost.
C. The region used by the VM instance: OCI pricing for the same resources varies between different geographic regions. Therefore, the selected region is a direct factor in the cost of a VM instance.

1. Oracle Cloud Infrastructure Documentation

Compute Pricing: "For virtual machine (VM) and bare metal instances

you pay for the resources when the instance is in the running state. ... For some images

such as Windows Server images

you are also billed for the operating system license." This statement confirms that the OS (Option B) is a cost factor. The same document outlines that billing is based on OCPUs and memory

which are determined by the size/shape (Option A).

2. Oracle Cloud Infrastructure Price List (cloud.oracle.com/price-list): The official price list demonstrates that costs for compute instances vary based on the selected Region (Option C)

the Shape (Option A)

and the Operating System/Image (Option B). For example

the price for a "VM.Standard.E4.Flex" shape is different in "US East (Ashburn)" versus "UK South (London)". It also shows a separate

additional cost for a "Windows Server Standard" image compared to Oracle Linux. The pricing is listed per unit (e.g.

OCPU per hour)

which is not affected by the quantity of other units running.