Before revision:  However, these tools were developed years ago when hardware was less powerful and software had fewer features. For example, unified memory was introduced in CUDA 6 as a new programming model and wasn't available when Rodinia was released. Meanwhile, the increasing demand for graphics processing units (GPUs) due to the recent rise in popularity of deep neural networks (DNNs) has opened doors for many new research problems.
After revision:  However, these tools were developed years ago when hardware was more limited, software supported fewer features, and production hardware-accelerated workloads were scarce. Since that time, GPU compute density and memory capacity has grown exponentially, programmability features such as unified memory, demand paging, and HyperQ have matured, and new workloads such as deep neural networks (DNNs) has opened doors for many new research problems.