Intel Corp (INTC)

[Saturn V]

Hi ChipGeek,
Multithreading and Turbo Boost will give rise to interesting issues for an Operating System on how to allocate threads between multiple cores.

For example if have 4 threads which need to be executed on a 4 core , 8 thread chip. How should the threads be allocated ?

To take advantage of Turbo Boost the four threads should be allocated to two cores, and this will allow taking advantage of TurboBoost. However in some situations having one thread per core,gives each thread exclusive use of the L1 cache and all the other ALU and other Core resources. I can see that if two threads belong to the same program, they would share data and thus a common core for both would make sense. However threads belonging to independent modules would not share data, and would benefit by having an exclusive access to the core resources.

So the thread allocation strategy is not obvious at this point in time.

Is turning on the Turbo Boost under OS control or is it hardwired into the hardware logic of the processor ?

Another issue is that if you have eight threads being executed, and then a few terminate, will it make sense for the OS to move the threads to get an optimal performance configuration ?

Interesting issues !

I agree that the TurboBoost will 'Boost' the sales of 4 core Nehalems on the desktop.