What is a vCore in VPS hosting?

Anyone interested in a virtual server will quickly come across the term vCore in the performance descriptions of the various VPS offerings on the market. The more vCores a VPS provides, the more expensive it usually is, and customers naturally expect greater performance as a result. What exactly does the term vCore mean in the context of a VPS?

What does the term vCore mean?

In the hosting sector and in the context of a VPS, the term vCore refers to virtual CPU cores. It therefore denotes the number of virtual processor cores that are provided to a customer on a virtual server.

Warning — potential for confusion: the term Vcore (written with a capital "V" and a lowercase "c") is used in electronics and information technology in connection with processors to denote the core voltage, i.e. the processor core voltage!

While with dedicated servers, where the entire capacity of the system can be used exclusively, customers can be guaranteed dedicated CPU cores, with VPSs only virtual processor cores, i.e. a certain number of vCores, can be allocated. However, it is not always entirely clear what performance a vCore actually delivers.

What performance does a vCore provide?

A blanket statement cannot be made about the specific performance potential of a vCore. To make a better assessment, however, one must consider the concept of threading in processors.

The technology known as "Hyper-Threading" was originally developed by Intel and has since been adopted by other manufacturers such as AMD. It is a specific implementation of hardware-based multithreading within the processor itself. By using multiple complete register sets and a complex control unit, threading allows the processor to handle two parallel instruction and data streams internally.

In simple terms, threading therefore enables the presentation of two logical processor cores even though only a single physical core is present. As a result, for example, a 4-core processor can effectively operate as 8 cores (also called "threads").

Even in the virtualisation of servers, this technology can be used. In this way, more individual processor cores can be made available to a VPS. However, this works only in theory as well as it sounds. After all, a "thread" is not a fully fledged processor core with full performance.

Hosting providers use the term vCore for the virtually provided processor cores on VPS hosting. Theoretically, these should therefore be the equivalent of a "thread" and provide 100% of the performance to the customer. In practice, however, it usually looks very different. Particularly cheap VPSs are typically oversold. This means the system has been allocated more resources than it actually has available. The customer can then often only use around 50% of a "thread"'s performance as a vCore, because they share the full performance with other customers on the system. Under high load the processor can no longer process steps in parallel, but executes them sequentially. The result is higher latency and longer load times.

How many vCores should a VPS have?

Although it is not possible to state categorically what performance a single vCore will actually deliver on a VPS, it is nevertheless reasonable to assume that a higher number of vCores will provide higher performance. This is especially true when comparing the different VPS plans offered by a particular provider.

It is more difficult, however, to weigh up the offers of two different providers that each make a similar number of vCores available. Without further information on the technical implementation of the respective VPS hosting, it is hardly possible to determine definitively which virtual server delivers the higher performance. After all, a VPS hosting plan with 4 vCores, where the performance can be used by the customer at 100% at all times, can easily be the higher-performing system overall than a VPS hosting plan with 6 vCores where only 50% of the processor core’s actual performance is available.

Our article is based on our own experience and research, as well as information from external sources.

Sources & further links on the topic:
https://www.intel.de/content/www/de/de/gaming/resources/hyper-threading.html (Information on Hyper-Threading)