How many MT5 access servers does a broker need?
The answer depends on client geography, peak concurrency, latency objectives, resilience and operational design. Access-server count should be based on measurable demand and failure scenarios rather than an arbitrary fixed number.
Start with geography
Map active and expected clients by region, not just registered accounts. Network distance and internet routing can affect login and data-delivery experience.
Add resilience
Capacity should account for maintenance and failure scenarios. A topology that only works when every node is healthy has little operating margin.
Re-evaluate with growth
Track per-node load, network metrics and regional demand so additional capacity is introduced before persistent congestion appears.