Behaviour and Performance of Interactive Multi-player Game

Servers

Ahmed Abdelkhalek, Angelos Bilas, and Andreas Moshovos

Introduction

• Investigate the scalability of services provided by servers

• Multi-player games are enabled by a central server

• FPS typically supports under 70 users

The First Experiment

• 32 PII-400 MHz computers

• Machines connected on the same LAN

• Quake (FPS game)

• 1 human controlled player with the rest being automated players

Server incoming network throughput per client

Server outgoing network throughput per client

Server response size

Server received request rate

Server response rate (relies/s)

Server execution time breakdown

Graphics Rendering Time for Clients

Server response rate as measured at the clients

The Second Experiment

• Each client computer simulates 16 players

• Compare statistics on two maps, a small map and a big one

• use PIII-800 MHz computer as server later

• Use EMON to monitor the CPU statistics

Server response rate (small map)

Server outgoing network throughout per client

Server execution time breakdown (small map)

Request processing time at the server (small map)

Server response size (small map)

Server response rate (large map)

Server execution time breakdown (large map)

Request processing time at the server (large map)

Server response rate (800MHz processors, large map)

Request processing time at the server (800MHz processors, large map)

Server execution time breakdown (800MHz processors, large map)

Server CPU Behaviour

Conclusion

• Network bandwidth is not an issue• Incoming bandwidth per player on server is

constant with increasing number of players• Outgoing bandwidth per player increases

with increasing number of players• Memory requirement is not an issue• Use server response rate and average

response time for evaluation

Conclusion (cont’d)

• Can support between 60 to 100 players with the equipment

• Server utilization increases linearly with the number of players

• Doubling the speed of CPU results in a less than double increase in the number of players

• Room for improving server performance at the microprocessor architecture level