Infrastructure

Colocation: what it is and when it beats pure cloud

Deciding where to host IT infrastructure is rarely black and white. Between building your own data centre and moving everything to the public cloud sits a middle ground that many companies end up choosing: colocation. Understanding what it is and how it differs from pure cloud helps you make a decision that will shape cost, control and operational performance for years.

What is colocation?

Colocation means housing a company's own hardware (servers, storage, network equipment) inside a third party's data centre. The provider supplies the facility: redundant power, specialised cooling, physical security, connectivity and certifications. The company keeps ownership and control of its equipment but is freed from building and running the building that supports it.

It is a hybrid model by nature: it combines control of your own hardware with the enterprise-grade infrastructure of a professional data centre, without the outlay of putting one up. That is why it is the option many organisations arrive at once they have outgrown a server room but cannot justify (or do not want) building their own facility.

What is pure cloud?

In pure cloud, the company owns no hardware: it consumes compute, storage and network as a service, over the internet, and pays for what it uses. The cloud provider owns and operates all the physical infrastructure. The appeal is elasticity (scaling in minutes, without buying equipment) and speed of deployment, which makes it ideal for variable or hard-to-predict workloads.

The trade-off lies in the cost model and control. Pay-per-use is convenient, but at scale and with stable workloads the bill can grow beyond expectations, particularly once data transfer charges are added. And customisation is limited to what the provider offers, which can create dependence on its platform.

Colocation vs pure cloud: a direct comparison

Criterion	Colocation	Pure cloud
Hardware ownership	The company's	The provider's
Cost model	Investment + rent (CapEx/OpEx)	Pay-per-use (OpEx)
Scalability	Bounded by installed capacity	Elastic, almost immediate
Control and customisation	Total over the hardware	Limited to the provider's offering
Cost predictability	High, with stable workloads	Variable, sensitive to usage and egress
Ideal for	Stable workloads, control, compliance	Variable workloads, fast deployment

Own analysis, based on comparative IT infrastructure studies.

When does each one make sense?

Colocation makes sense when the company values control over its hardware, has stable and predictable workloads, or faces compliance requirements that demand knowing exactly where and how data is held. Because it is your own infrastructure in a certified facility, it offers predictable costs and consistent performance for whatever runs permanently.

Pure cloud makes sense when elasticity is the priority: workloads that rise and fall, short-lived projects, development environments or services that need to be deployed in minutes. Its strength is absorbing demand peaks with no prior investment in hardware.

Total cost, beyond the monthly bill

One of the most common mistakes when comparing colocation and cloud is looking only at the initial outlay or at a single month's bill. Pure cloud is attractive because it requires no hardware investment and its entry cost is low, but at scale and with stable workloads, pay-per-use can accumulate beyond expectations, especially once data transfer charges (egress) are added, which penalise backup, analytics or cross-region replication.

Colocation inverts the equation: it demands an upfront investment in hardware and a space commitment, but offers predictable, stable costs for whatever runs permanently. To decide with any rigour, it is worth modelling total cost of ownership over several years (three to five is a reasonable horizon), including hardware, rent, connectivity, staff, data transfer and the cost of an eventual future migration. That full comparison, and not a single month's rate, is what reveals which model works out better for each type of workload.

Other factors that tip the balance

Beyond cost, two considerations weigh on the decision and often settle it:

Compliance and data control

Operations subject to regulation (or with strict requirements about where data resides) find an advantage in colocation: the hardware is your own and sits in a known, controlled location, which simplifies demonstrating compliance and reduces audit complexity. In pure cloud, that control is more indirect and depends on the provider's assurances.

Provider dependence

Pure cloud, particularly when it relies on highly proprietary services, can create a dependence that is hard to reverse: migrating applications designed for a specific platform carries a high engineering cost. Colocation, by keeping control of the hardware and favouring portable architectures, reduces that risk of being tied to a single provider and preserves strategic flexibility.

Performance, a factor that gets underestimated

When comparing infrastructure models, there is a lot of talk about cost and control, but performance deserves a place of its own. In a multi-tenant public cloud environment, resources are shared among many customers, and that can translate into variability: disk performance, processing capacity or network latency may fluctuate depending on the load from other users on the same infrastructure. For transactional or response-time-sensitive applications, that variation is not always acceptable.

Colocation offers dedicated hardware: the company runs its own equipment without sharing it, with predictable performance and the ability to tune the configuration to its most demanding workloads. For intensive operations (large databases, heavy compute loads, applications that tolerate no variation) that consistency can be decisive. It is not that cloud cannot serve those cases; it is that colocation gives a level of control over performance that the shared model cannot guarantee in the same way.

What does the transition look like in practice?

Adopting a hybrid model does not mean moving everything at once. Most organisations arrive at it gradually: they identify which workloads are better kept under control (for stable cost, compliance or performance) and place those in colocation, while leaving in the cloud those that benefit from elasticity. Over time, they adjust the distribution based on what the real operation shows.

The key to making that model work is the connectivity between both environments. A well-designed hybrid architecture needs quality links between colocation, cloud and sites, because the performance of the whole depends on the weakest link. That is why, when planning the transition, connectivity is not an afterthought: it is part of the design from the start.

The answer is usually hybrid

In practice, the question is rarely settled by choosing just one. Most organisations end up in a hybrid model: stable, sensitive or regulated workloads live in colocation or their own infrastructure, and elastic or fast-scaling workloads run in the cloud. The mature decision does not start from dogma but from mapping each workload by its profile (cost, latency, regulation, variability) and placing it where it makes most sense.

That hybrid approach makes connectivity between both worlds decisive: colocation only performs if the connection to the cloud and to the sites is up to standard. Having a provider that integrates data centre, regional connectivity and IT infrastructure makes it simpler to sustain that mixed architecture without weak links.