"A Fundamental Turn Toward Concurrency in Software"

[Steve Horsley]

Jack Diederich wrote:
> On Fri, Jan 07, 2005 at 01:35:46PM -0800, aurora wrote:
> 
>>Hello!
>>
>>Just gone though an article via Slashdot titled "The Free Lunch Is Over: A  
>>Fundamental Turn Toward Concurrency in Software"  
>>[http://www.gotw.ca/publications/concurrency-ddj.htm]. It argues that the  
>>continous CPU performance gain we've seen is finally over. And that future  
>>gain would primary be in the area of software concurrency taking advantage  
>>hyperthreading and multicore architectures.
> 
> 
> It got most things right, AMD & Intel are moving towards multiple cores on
> a chip so programmers will adapt.  I don't see this as a big deal, the current
> trend is rack farms of cheap boxes for heavy computing needs.  Multi-core CPUs
> will help those kinds of applications more than single threaded ones.  Existing
> threaded apps don't have to worry at all.
> 
But my understanding is that the current Python VM is single-threaded internally,
so even if the program creates multiple threads, just one core will be dividing
its time between those "threads".

> His picking on Intel to graph CPU speeds was a mistake (I'll be generous and
> not say deliberate).  Intel screwed up and pursued a megahertz-at-all-costs
> strategy for marketing reasons.  AMD didn't worry about MHz, just about CPUs
> that did more work and so AMD is eating Intel's lunch.  Intel has abandoned
> their "faster" line of processors and is using their CPUs that are slower in
> MHz but get more work done.   So the author's "MHz plateau" graph isn't all
> Moore's law breaking down, it is the result of Intel's marketing dept breaking
> down.
> 

You may be right, but I agree with the thrust of the article that multicore
looks to be the new in thing at the moment. 

Steve