The Effects of Frame Rate and Resolution on Users Playing First Person Shooter Games

1. The Effects of Frame Rate and Resolution on Users Playing First Person Shooter Games Kajal Claypool Feissal Dama Mark Claypool CS Department Worcester Polytechnic Institute CS Department University of Massachusetts, Lowell http://www.cs.wpi.edu/~claypool/papers/fr-rez/

2. Computer Games and Performance • Latest computer games push capabilities of hardware in “quest” for more detailed, realistic graphics • Single game runs on varied hardware • PC : Old (600 MHz P3, 32 MB Video) or New (3 GHz P4, 256 MB Vid) • Platform: PC, Console (i.e. Xbox), Hand-held (i.e. PSP) • Result: Uneven hardware capabilities, opportunities for performance tuning • Key factors for game performance are: • Frame Rate – higher frame look smoother, provide more temporally precise feedback • Frame Resolution – higher resolutions look better, provide more visually precise feedback MMCN, San Jose, California

3. Motivation • Unfortunately, often cannot have both high Frame Rate and high Frame Resolution • Ex: Hand-held devices have constrained resources (small screens, limited power) • Ex: Older computers (often, only 1 year!) cannot run latest games at maximum frame rate or resolution • Tradeoff between Frame Rate and Frame Resolution • Higher resolutions mean lower frame rates and vice versa • How are frame rates and resolutions chosen? • Game console designers and hand-held designers choose resolution for user • Frame rate may depend upon processing load • PC gamers choose it by “feel” • Not guided by science MMCN, San Jose, California

4. Related Studies • Passive Users [1,2,3,4,5,6,7] • Users assess video with various frame rates and resolutions • Generally, decrease resolution then decrease quality, but decrease in frame rate less so • Active Users [8,9,10,11] • Users perform tasks under various frame rates and frame resolutions • Generally, extremely low frame rates impact performance, but frame rates of 4+ can be acceptable • Overall - more passive than most games and tradeoffs not compared • Our goal – Effects of Frame Rate and Frame Resolution on User Performance for Games MMCN, San Jose, California

5. Outline • Introduction (done) • Methodology (next) • Results • What’s Going On? • Conclusions MMCN, San Jose, California

6. Methodology Outline • Select game • Build custom map • Select parameters • Build test harness • Solicit users • Analyze results MMCN, San Jose, California

7. Methodology – Select Game • First Person Shooter (FPS) • Popular genre, especially for online play • Requires intense player interaction with time-critical decisions • Impairment to the display quality can cost virtual lives • Quake III Arena • Still fairly popular (~700 active servers via GameSpy) • Representative of current FPS games in terms of perspective, weapon choices and gameplay • Allows control of frame rate and resolution at startup MMCN, San Jose, California

8. = spawn point Methodology – Custom Map • Minimize effects of other players • Use Bot (Xaero) • Minimize movement • Chasm cannot be jumped • Wall behind player so doesn’t fall off accidentally • Maximize aiming and shooting • No cover (save wall to protect spawn point) • Use of railgun that cannot be rapidly fired • One shot per kill Opponent Platform (Chasm) User Platform MMCN, San Jose, California

9. Example Frame rate: 30, Resolution: 640x480 MMCN, San Jose, California

10. Methodology – Demographics Demographics provided once, before maps started MMCN, San Jose, California

11. Methodology – User Perception User perception provided after each map played MMCN, San Jose, California

12. Methodology – Parameters • 5 frame rates: 3, 7, 15, 30 and 60 fps • Ranges previously studied • May appear during normal game play • 3 frame resolutions: 320×240, 512×384, 640×480 • Hand-held devices to low-end PCs • Observed trend may interpolate to higher resolutions MMCN, San Jose, California

13. Methodology –Test Harness For each player … • Gather demographics • Play Quake III • Very high frame rate (80 fps) • Very high frame resolution (1024×768 pixels) • Shuffle (Frame Rate, Frame Resolution) combos • For each combo … • Play Quake III with (Frame rate X, Resolution Y) • Gather user perception MMCN, San Jose, California

14. Methodology – User Solicitation • Two-week period • Game played on isolated PC in lab • Range of enticements: • Enter raffle for three $50 gift certificates • Extra credit for courses • Refreshments for participants MMCN, San Jose, California

15. Outline • Introduction (done) • Methodology (done) • Results (next) • What’s Going On? • Conclusions MMCN, San Jose, California

16. Aggregate Statistics • 60 users provided “clean data” • 64 participated, but 4 removed because ended early • Age: • Most (~75%) 16-25 years old (ugrad CS students) • Almost 25% over 25 years old (grad CS students) • Gaming: • Over 65% played games over 1 hour per week • 25% played 6+ hours per week • 50% casual gamers, moderate at shooters • Gender: • About 20% female • Only one more than casual gamer, compared to about 65% for males MMCN, San Jose, California

17. PerformanceandFrame Rate (Resolution: 512x384 pixels) MMCN, San Jose, California

18. PerformanceandFrame Resolution (Frame Rate: 15 fps) MMCN, San Jose, California

19. PerceptionandFrame Rate (Resolution: 512x384 pixels) MMCN, San Jose, California

20. Perceptionand Frame Resolution (Frame Rate: 15 fps) MMCN, San Jose, California

21. Outline • Introduction (done) • Methodology (next) • Results (done) • What’s Going On? (next) • Conclusions MMCN, San Jose, California

22. Effects of Frame Rate on User Performance 60 fps 15 fps 7 fps 3 fps MMCN, San Jose, California

23. Example – 15 Frames per Second MMCN, San Jose, California

24. Example – 7 Frames per Second MMCN, San Jose, California

25. Example – 3 Frames per Second MMCN, San Jose, California

26. Effects of Frame Resolution on User Performance 640 x 480 320 x 240 MMCN, San Jose, California

27. Example – Resolution 320x240 Frame rate: 30 MMCN, San Jose, California

28. Conclusions • Frame Rate larger impact on performance than Frame Resolution • Frame Rate critical for adequate game performance • Frame rates of 3 fps and 7 fps not playable • 60 fps provides 7-fold increase over 3 fps • Frame Resolution has little effect on user performance • Users as effective at 320×240 as at 640×480 • Frame Rate and Frame Resolution both important for user perception • Effect of frame resolution similar to effect of frame rate • Top frame rate tested (60 fps) shows limit • Top resolution tested (640x480) not at limit • Perceived quality increases linearly with square pixels • Dramatically different previous research on video • Showed converse, that Frame Resolution mattered more • Suggests challenges in designing devices for games and video MMCN, San Jose, California

29. Future Work • Other aspects of First Person Shooters • Different map conditions • Movement • Other display tradeoffs • “Quality” from graphics effects • Anti-aliasing, realistic water/grass … • Additional demographics studies • Gender, age, gaming experience … • Other computer games • Real-Time Strategy, Sports … MMCN, San Jose, California

30. The Effects of Frame Rate and Resolution on Users Playing First Person Shooter Games Kajal Claypool Feissal Dama Mark Claypool CS Department Worcester Polytechnic Institute CS Department University of Massachusetts, Lowell http://www.cs.wpi.edu/~claypool/papers/fr-rez/