Of course, the real game-changer here is performance. For the first time, Halo 5 is built from the ground up with 60fps gameplay in mind. However, the question of whether 343 can hit that target with an acceptable level of consistency is still open to question, based on the E3 showing. While last year's multiplayer beta turned in relatively solid frame-rates, the conference campaign footage raises some concerns. Based on the demo, it seems that the target is a 'perceptual' 60fps experience more in line with the Call of Duty titles. That is, while the target remains 60fps, performance levels often dip below during action sequences.
The question is to what extent 343 will allow performance to deviate from the desired frame-rate - and right now, to be brutally frank, the E3 experience is some way off the level of consistency we want from the final game. This could wind up becoming a real issue if there isn't sufficient improvement: right now, only the quietest of moments delivers a completely stable frame-rate: every battle sequence in the demo suffers from noticeable drops - something we observed not just in the media briefing live demo, but in 343's own b-roll footage.
It's clear that performance is an important focus for Halo 5 and we applaud 343 for committing to a top-tier 60fps target when so many other games ship at 30fps or below. Keeping this goal in mind lends additional credibility to a wealth of evidence suggesting that 343 is experimenting with a dynamic resolution framebuffer. By adjusting pixel count based on engine load, this feature could allow Halo 5 to maintain a higher frame-rate at the expense of image quality during action heavy sequences. In its current form, this is clearly evident both in campaign and Warzone footage. In theory, it sounds like a promising solution, but Frank O'Conner again cautions that "there's zero permanent resolution information to take away from E3."
The current dynamic frame resolution system can actually be observed in more detail within the 'Road to E3' video published on the Halo Channel a few weeks back, and embedded below. It provides a closer look at the game in a debug state, complete with important performance statistics visible on-screen, as the camera is flown in and around the environment. We can see the horizontal resolution apparently shift dynamically between a full 1920 all the way down to 832 pixels. With 810 vertical lines in play we're looking at a resolution ranging from 1920x810 to 832x810. However, in b-roll distributed during E3, minimum resolution observed comes in at 1152x810 - not exactly wonderful but presumably more indicative of where the system is right now during gameplay.
The drive to optimise performance has implications elsewhere. Independent of rendering resolution, we also see plenty of low-resolution transparent alpha effects. Smoke and particles are rendered at a resolution low enough to produce noticeable saw-tooth edges where they intersect with the silhouette of the view weapon. This could be the key to delivering a stable 60fps experience, and right now it does seem that 343 is running the gamut of well-known techniques designed to ease up on GPU utilisation.
https://www.youtube.com/watch?v=To4Tx3FG6zs
https://www.youtube.com/watch?v=2Wgx4E_21D4
http://www.eurogamer.net/articles/digitalfoundry-2015-can-halo-5-deliver-on-its-60fps-promise