This blog forms part of the http://performanceGuru.com website which focuses on performance tuning UNIX-like Operating Systems (including Linux).
There is yet another excellent article
in ACM Queue
outlining the past, current and future state of processors. One of the co-authors of the article is Kunle Olukton who founded Afara Websystems which was purchased by Sun Microsystems.
The technology developed by Afara prior to the purchase was later to become Niagra and the article focuses closely on CMP (Chip Multi Processing) as well as SMT (Simultaneous Multithreading).
The article covers the triad of modern chip design clock frequency, superscalar instruction issue and multi-threading, revealing the delicate trade-offs that are now in place and likely future directions now that two of the three avenues have been fully exploited. The article covers the background of Intel
current processor design direction and if you play close attention there might be a taste of what is in the forthcoming Rock CMP/SMT play from Sun Microsystems
All-in-all a recommended read!