Why bare metal wins The difference is not subtle when the GPU is yours alone.
The GPU chip is only part of the story. Serious AI work depends on the
surrounding machine: CPU, memory, storage, networking, operating system,
drivers, scheduler, and the ability to tune them together.
Factor Bare metal GPU server Virtual GPU instance
What you get The full physical server, every GPU, every NIC, and every PCIe lane belong to one tenant. A VM gives you an abstraction. The platform still controls the host, placement, and boundaries.
Throughput Built for long runs, high utilization, low jitter, and direct access to the machine underneath. Fine for quick tests, but the VM layer and shared fleet policies become a tax when jobs run hard.
Control Root access, driver control, scheduler control, storage control, and no hypervisor in the critical path. The provider decides how much of the stack you are allowed to touch.
Cluster design Scale with whole nodes and planned 400 Gb/s InfiniBand or 800 Gb/s Spectrum-X fabric. Scale by requesting more instances, then hoping the placement and network are good enough.
Economics When GPUs stay busy, whole-server capacity turns cloud unpredictability into a flat operating line. Convenient for bursty tests, expensive when always-on work keeps renting metered slices.