In our PC-based tests, having SMT enabled can deliver up to 30 per cent - or more - of additional performance in well-threaded applications. However, for launch titles at least, Microsoft expects developers to opt for the higher 3.8GHz mode with SMT disabled. "From a game developer's perspective, we expect a lot of them to actually stick with the eight cores because their current games are running with the distribution often set to seven cores and seven worker threads," explains Microsoft technical fellow and Xbox system architect Andrew Goossen. "And so for them to go wider, for them to go to 14 hardware threads, it means that they have the system to do it, but then, you have to have workloads that split even more effectively across them. And so we're actually finding that the vast majority of developers - talking with them about the their choices for launch - the vast majority are going to go with the SMT disabled and the higher clock."