Chiplets have been a discussion topic for years now, referenced as the next step in producing high-performance CPUs. In a world where bigger performance means bigger chips, which also means bigger costs, chiplets could be the answer that a lot of manufacturers are looking for. As luck would have it, however, something that could change up the market like that and make it easier to manufacture CPUs is not quite as easy as you might think.
The idea behind chiplets is that you can create a tighter configuration of CPUs and GPUs by mounting them all on a piece of silicon, the interposer, which contains interconnections and routing circuits, The right data goes to the right place. It’s all well and good, except for one thing. All those pathways on the silicon with those stuffed together chiplets could cause a problem where data is moving all at once and it gets deadlocked in a certain area, with data just waiting for the other piece of data to move nothing happens. Gabriel Loh, Design Engineer at AMD, describes this problem pretty well: “Each of those individual [chiplets] could be designed so that they never have deadlocks…But once I put them together, there are now new paths and new routes that no individual had planned for ahead of time.” If they try to design chiplets with specific interposers in mind, it could make the design less compatible with other developers as well as lessen how well it could be optimized.
But that doesn’t scare off the creator of the monster they call Threadripper, AMD is sinking money into researching this problem so that chiplets can be the future. In fact, they’ve already been using chiplet technology in the form of multi-die CPUs when they made the Threadripper to connect multiple processors. They think they might’ve come to a solution for the silicon problem, as it turns out if you follow a few easy rules while designing the chiplets like restricting how information can come into and out of the chip, and restricting where the data can go when it first enters the chip.
There’s no telling when this technology will finally come to fuition in the mainstream market. AMD is already using interposers in their Radeon R9 line using interconnects but not network circuits, but improving those with circuits could lead to huge advances in the construction of those chips.