Cloud gaming is increasingly popular. A challenge for cloud provider is to keep datacenter utilization high: a non-trivial task due to application variety. These applications come in different shapes and sizes. So do cloud datacenter resources, e.g., CPUs, GPUs, NPUs. Part of the challenge stems from game engines being predominantly designed to run only one player. For example, one player in a lightweight game might utilize only a fraction of the cloud server GPU. The remaining GPU capacity will be left underutilized, an undesired outcome for the cloud provider. We introduce Capsule, a mechanism to seamlessly share one GPU, and other cloud servers resources, across multiple players. Sharing makes the cost of multiple players sublinear. We implemented Capsule in O3DE, a popular open source game engine. Our evaluations show that Capsule increases datacenter resource utilization by accommodating up to 2.25x more players, without degrading player gaming experience. This is the product of Capsule using up to 1.43x less GPU, 3.11x less VRAM, 3.7x less CPU, and 3.87x less RAM compared to the baseline. Capsule is also application agnostic. We ran four applications on Capsule-based O3DE with no application changes. Our experiences with four applications, three servers with different hardware specifications, including the one with four GPUs, and multi-server cluster show that Capsule design can be adopted by other game engines to increase datacenter utilization across cloud providers.

翻译：云游戏正日益普及。云服务提供商面临的一项挑战是保持数据中心的高利用率：由于应用程序的多样性，这是一项艰巨的任务。这些应用程序具有不同的形态和规模。云数据中心的资源（如CPU、GPU、NPU）亦是如此。部分挑战源于游戏引擎主要设计为仅运行单一玩家。例如，一个轻量级游戏中的单个玩家可能仅占用云服务器GPU的一小部分。剩余的GPU容量将被闲置，这对云服务提供商而言是不希望看到的结果。我们提出了Capsule，一种能够在多个玩家间无缝共享单个GPU及其他云服务器资源的机制。共享机制使得多玩家的成本呈次线性增长。我们在流行的开源游戏引擎O3DE中实现了Capsule。评估结果表明，Capsule通过支持多达2.25倍的玩家数量提升了数据中心资源利用率，且未降低玩家的游戏体验。这得益于Capsule相较于基线方案，GPU使用量减少达1.43倍，显存使用量减少达3.11倍，CPU使用量减少达3.7倍，内存使用量减少达3.87倍。Capsule还具有应用无关性。我们在基于Capsule的O3DE上运行了四个应用程序，无需对应用程序进行任何修改。我们在四款应用程序、三台具有不同硬件规格的服务器（包括配备四块GPU的服务器）以及多服务器集群上的实验表明，Capsule的设计可被其他游戏引擎采用，以提升跨云服务提供商的数据中心利用率。