VPS or Dedicated Server: When to Switch

We have this conversation with clients regularly: the scraper started crashing at night, the database keeps growing, the admin panel feels sluggish, and the question comes up whether to take a bigger VPS or a dedicated server. There is no universal answer, but a few simple criteria get it right almost every time.

What the real difference is

A VPS is a slice of a large physical server shared between dozens of customers. You get a guaranteed share of CPU, RAM and disk, but the hardware is shared. The provider can sell more virtual cores than it has physical ones, because not every customer loads them at the same time.

A dedicated server is a whole physical machine: every core, all the RAM and the disks are yours alone. Nobody next door eats your performance, and you can use the resources at 100% around the clock.

Five signs your VPS is too small

1. RAM has become the bottleneck. Processes die with out-of-memory errors and swap is permanently in use. RAM is the most expensive thing on a VPS: every 8 GB costs real money, while a dedicated server comes with 128 GB "included".
2. Performance fluctuates. The same scraper finishes in 20 minutes today and an hour tomorrow although you changed nothing. That is your neighbours on the physical host. A dedicated server does not have them.
3. The disk slows down the database. Queries that should be instant wait for the disk. On a VPS disk throughput is shared; on a dedicated server you know your NVMe drives and nobody else loads them.
4. You run three VPSes instead of one server. A bot, a scraper, a database, a staging box, each on its own 10-20 € VPS. Together that is already the price of a dedicated server where all of them would fit with room to spare.
5. You need sustained full load. Video processing, a self-hosted language model, transcoding, computation. VPS providers do not like a CPU pinned at 100% for days and may throttle you. A dedicated server is built for exactly that.

When the switch pays off, and when it does not

Compare the price per unit of resource, not the product name. Pick what you lack most, RAM, cores or disk, and look at what a gigabyte or a core costs on the next VPS tier versus a dedicated server. The usual picture:

• Short of RAM or disk: dedicated is almost always cheaper per gigabyte. That is why old Xeons with 256 GB of RAM sell for less than top VPS plans.
• Short of single-core speed: do not rush. Modern VPSes on AMD EPYC beat 2015 Xeon dedicated servers in single-threaded work, and websites and bots care about exactly that.
• Short of stability: if performance dips cost you money, for example a scraper not finishing by morning, a dedicated server pays for itself in peace of mind.
• Need to grow unpredictably: VPS. Upgrading a tier takes a minute; replacing a dedicated server means a migration.

Among the providers we work with, Contabo offers the most interesting ratio: VPS to start with, Server Deals, a page of fixed-configuration dedicated servers at up to 57% off, and the full dedicated server line-up on current hardware for those who need a specific configuration. The pros and cons in detail are in our Contabo review.

The catches of dedicated servers

• Old hardware at a low price. Cheap dedicated servers are usually Xeon E5 v3 and v4, that is 2014-2016. Great for databases and parallel work, slower than a new VPS for single-threaded tasks. Look at the CPU generation, not just the core count.
• No RAID, or a single disk. Check the configuration. With a single disk, backups stop being optional.
• Setup is on you. A bare server with an operating system. Firewall, updates, monitoring, backups, Docker all have to be installed and maintained.
• Slower replacement. A VPS restarts in seconds on another node; a dedicated server with failed hardware takes hours to repair. For critical services keep backups and a migration plan.
• Availability. Discounted configurations go fast, and the same server may be gone a month later.

Pricier servers: the first two problems go away

The first two points apply to the cheapest offers only. Contabo's full dedicated server line-up runs on current CPUs, recent-generation AMD EPYC and Intel Xeon, which match a new VPS in single-threaded work and beat it several times over in parallel work. The disks are NVMe in RAID, the memory is ECC, up to 1 TB, and you can shape the configuration to the job: more cores for computation, more RAM for a database, more disks for an archive. That costs hundreds of euros a month, but the same performance on a VPS would cost far more, if such a plan existed at all. Setup, backups and a migration plan still stay with you; that is a property of any dedicated server, not of the price.

How to migrate without downtime

1. Bring up the new server next to the old one. Do not switch the VPS off until everything runs on the new machine.
2. Move services into Docker if they are not there yet. Containers migrate with one command and the configuration lives in a repository.
3. Copy the data and verify. Database, files, secrets. Run everything on the new server under a staging domain and go through the main scenarios.
4. Lower the DNS TTL to 5 minutes a day before the move, so the domain switches quickly.
5. Switch the domain, watch the logs for a few hours and only then turn off the old VPS. Keep its backup for another week.

We do these migrations for bots, scrapers and CRMs: from choosing the server to setting up backups. If you are not sure whether you need a dedicated server yet, tell us what exactly is slow and we will say so honestly.