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Operating System Specific Discussions => Amiga OS => Amiga OS 4.x (future) Hardware Compatibility Discussions => Topic started by: takemehomegrandma on July 23, 2013, 11:39:27 AM

Title: OS4 won't have SMP after all
Post by: takemehomegrandma on July 23, 2013, 11:39:27 AM
Ssolie, the "OS4 development lead", has now confirmed (http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=37939&forum=32#713132) (for the first time, at least AFAIK) that the multi-processing system they are apparently working to bring to OS4.2 will not be   Symmetric Multi-Processing (http://en.wikipedia.org/wiki/Symmetric_Multiprocessor).

Everyone with a basic understanding of Amiga OS's design said that true SMP in Amiga simply isn't possible. With this in hindsight I think we are many who has been curious to see how Hyperion (who promised this feature (yes, true SMP) on numerous occasions and has also been selling new HW under these premises) would solve this little "problem".

And now it turns out exactly as everyone expected - it won't be SMP at all, it probably will be a variant of ASMP/AMP (http://en.wikipedia.org/wiki/Asymmetric_multiprocessing) instead. The easiest (and most probable) way would probably be by providing an API that new applications, that has specifically been written for this feature, can use to start up some number-crunching, encoding, decoding, compiling task or whatever on the second CPU, external and completely separate from the actual Amiga OS environment where everything else runs. This would probably be quite easy and has been discussed on other places (http://www.morphzone.info/modules/newbb_plus/viewtopic.php?topic_id=8831&forum=11#95821) already.

Question is how useful this will really be in practice, if it will be worthwhile at all? It won't benefit anything already existing out of the box, new applications will have to be developed or old will have to be modified, and the approach only make sense for a quite limited number of CPU-intensive applications anyway, not at all Amiga programs (or even the OS) in general.

Ssolie doesn't think this is a problem...

"users don't care if it is SMP or ASMP or WXYZ or whatever else as long as all the hardware they paid for is being utilized to run their software."

...but I think he might be in for a surprise there. The difference between true SMP and some simple ASMP/AMP implementation is huge and fundamental. Most of the benefits that people expects from having multiple cores at all simply isn't there in a non-SMP approach. We have seen many users on AW.net (and even here) eagerly comparing various upcoming PPC CPU's with 12 or even 24 cores and yada yada. But suddenly it became much less relevant to look at new multicore CPU's and their aggregated performance. Suddenly it's much less relevant to look at multicore CPU's at all...
Title: Re: OS4 won't have SMP after all
Post by: Tripitaka on July 23, 2013, 11:48:30 AM
Why do you even care? We all know your never going to buy an OS4 machine anyway.
Title: Re: OS4 won't have SMP after all
Post by: yssing on July 23, 2013, 11:53:19 AM
TMHGM that was not what he said.
Title: Re: OS4 won't have SMP after all
Post by: spirantho on July 23, 2013, 12:13:01 PM
I don't care what it's called - if I get to use all the cores available to me, I'm happy.
Title: Re: OS4 won't have SMP after all
Post by: takemehomegrandma on July 23, 2013, 12:34:03 PM
Quote from: Tripitaka;741726
Why do you even care?

Because this is one of the few last remaining myths/lies from Hyperion that is now unfolding and being revealed. SMP can't be done without breaking AMIGA, it's as simple as that. But Hyperion said it could, and they sold machines, dreams and hope based on this, collected money, used this as a false spec in dirty competition, etc. That's why this is important.


Quote from: yssing;741727
TMHGM that was not what he said.

Yes, that's exactly the essence of what he said, I even linked to the post above, please look at it again. SMP is a well known concept in the industry, with pretty clear definitions. There is no doubt surrounding it, nothing unclear.


Quote from: spirantho;741732
I don't care what it's called

It's not about what you "call" it, it's about what it *is*. SMP is called SMP, if it's something else, then you don't call it SMP (hence ssolie's post), it's as simple as that.

Quote
if I get to use all the cores available to me, I'm happy.
The practical difference between SMP and ASMP/AMP is fundamental, and SMP is undoubtedly what practically *everyone* means when casually talking about "multicore". I'd dare to claim that 99.9% of the people *won't* get to use all the cores available to them in OS4, at least not in the way they thought/expected to (that is: in the true SMP way).
Title: Re: OS4 won't have SMP after all
Post by: eliyahu on July 23, 2013, 12:39:24 PM
@TMHG

i read ssolie's words very carefully. he did not "confirm" anything. this entire thread is a perfect example of the foaming-at-the-mouth, juvenile, point-scoring crap that needs to end around here.

-- eliyahu