Exclusive Sun Microsystems looks poised to lead the "mainstream" multi-core race for at least a couple more years. By late 2009, the server maker should deliver a third major revision of its Niagara processor which will have 16 cores and an astonishing 16 threads per core, The Register has learned.

Today, Sun sells an eight-core "Niagara" chip that can handle eight software threads per core. Customers can fit two of these UltraSPARC T2+ chips, as they're officially called, into a server, providing up to 128 threads in a 1U system. Soon enough, Sun will also sell a four-socket system code-named Botaka.

We've confirmed that Sun is looking to push the UltraSPARC Tx line to even greater heights with a 16-core, 16-thread per core eight-socket server. So, each socket is chewing through an insane 256 threads. And the eight-socket box will do 2,048 threads.

That 16-core chip is the third major Niagara revision and is code-named KT. It's due to tape out in six months or so, as we hear it.

The new Niagara sounds an awful lot like Sun's other 2009 chip - Rock.

Rock does, in fact, have 16 cores as well, but they're beefier cores with better single thread performance. Sun is claiming that Rock can do two or four threads per core, depending on whether or not you turn on its Scout pre-fetching technology.

The UltraSPARC Tx line has turned into the shining star of Sun's SPARC server business, pulling in more than $1bn in sales per year. The problem, however, seems to be that the UltraSPARC Tx boxes eat up sales of other low-end systems, which has led to a steady decrease in shipments at Sun, while revenue has been flat to falling. ®