New 25-core chip can be scaled to create a 200,000-core computer

A team of researchers at Princeton University have developed a 25-core open-source processor called Piton that can be stringed into a 200,000-core computer.

The chip is designed to be flexible and quickly scalable. The 8,000 64-bit Piton chips will have to ensure the collection of cores are in sync when processing applications in parallel.

One Piton chip has 25 cores broken up into five lines, a topology often referred to as a mesh design. Each core operates at 1GHz, and multiple chips can be arranged in a chain system through a “bridge” that sits on top of the chip structure. Additionally, the bridge links the chip to DRAM and storage.

While the mesh design isn’t new, Piton is unique because it has a distributed cache and unidirectional links that can pull all cores together in a large server, sharing memory. Each core has 64KB of L2 cache, with a total of 1.6MB for the chip. A mini-router in each core guarantees fast communication with other cores. Each core also has a floating point unit, primarily for large-scale parallel computing.

The primary goal when designing Piton was to create a chip capable of being used in large data centers that handle social networking requests, search, and cloud services. The response time in social networking and search services is tied to the horsepower of servers in data centers.

Piton is a rare open-source processor based on the OpenSparc design, a modified version of Oracle’s OpenSparc T1 processor. SPARC is the architecture used by Oracle in its high-end servers designated for databases. 

The researchers noted that Piton is the largest chip in academia with 460 million transistors.

Source: PCWorld