Everything Old is New Again: Cray's CPU design
I found myself writing, during a commentary on the evolution of SSD's in servers , that large-slow-memory like Seymour Cray used (not cache), would affect the design of Operating Systems. The new scheduling paradigm: Allocate a thread to a core, let it run until it finishes and waits for (network) input, or it needs to read/write to the network. This leads into how Seymour Cray dealt with Multi-Processing, he used multi-level CPU's: There were Application processors, many bits, many complex features like Floating Point and other fancy stuff, but had no kernel mode features or access to protected regions of hardware or memory, and Peripheral Processors (PP's), really a single very simple, very high-speed processor, multiplexed to look like 10 small, slower processors that performed all kernel functions and controlled the operation of the Application Processors (AP's) Not only did this organisation result in very fast systems (Cray's designs were the fastest in t...