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The Apple News That Got Buried
An anonymous reader writes, "Apple's Showtime event was all well and good, but the big news today was on Anandtech.com. They found that the two dual-core CPUs in the Mac Pro were not only removable, but that they were able to insert two quad-core Clovertown CPUs. OS X recognized all eight cores and it worked fine. Anandtech could not release performance numbers for the new monster, but did report they were unable to max out the CPUs."
http://www.euglug.org/pipermail/euglug/2005-August /004338.html
Cheers!
From TFA:
There's a big difference between unable to and had a difficult time. When I first read the summary I thought that there must be some problem with the system if they're unable to get all the CPUs under full load.
Trying this on macosx, the bomb dies when the number of forks exceeds a certain depth. So it's harmless. :(){ :|:& };:
$ bash: fork: Resource temporarily unavailable
bash fork Resource temporarily unavailable
bash fork Resource temporarily unavailable
bash fork Resource temporarily unavailable
bash fork Resource temporarily unavailable
bash fork Resource temporarily unavailable
bash fork Resource temporarily unavailable
bash fork Resource temporarily unavailable
Done
Some drink at the fountain of knowledge. Others just gargle.
Let's assume for the moment that none of us in this forum actually know anything factual about how many years Apple (or even NeXT before them) have been running Mach on machines with more than 4 processors on the corporate campus behind locked doors.
However, we can probably reason this out if we try. We're all bright geek types, right? There are several clues. NeXT bought Apple for a negative $400 million or so in what, December of 1996?
The heritage of NeXT that you mention is a pretty big clue. I don't recall off the top of my head how many processors were supported by the production shipping Mach build for SPARC and PA-RISC back in the NeXT days, but let's assume it was 2, just for the sake of argument. Both of those platforms offered ready availability of systems with many processors even way back then. Perhaps there were systems like that in the lab.
Mach was originally a research project with an interesting goal: clean support of certain abstractions in a platform-independent way. One of those abstractions was support for multiple processors, beyond the typical SMP architectures we see today, which means that the author's concept of platform-independent went quite some distance beyond a different instruction set in a different risk architecture. Dig this:
That text is unattributed at the Wikipedia page, but comes from this document: Appendix B from the book: Operating System Concepts
An excellent book entirely about Mach is: Programming under Mach, which also mentions the design intent.
The original project was funded by DARPA, with the specific goal of developing operating systems technologies which would support super computers with hundreds or thousands of processors.
The Mach project developed new techniques which have migrated directly (via actual Mach code to OSF, NeXT, Mac OS X, et. al.) or indirectly into pretty much every modern operating system.
Mach research spanned a very long period of time, and two Universities. Curious, bright, and arguably insane people (or they would have been making money instead of slaving away making Mach on grad-student salary) with access to multiple processor machines with DARPA funded directives to make it scale to hundreds of processors. Hmm... that seems like a clue.
NeXT was, and Apple is a hardware engineering company. Apple has been building multiple processor boxes since before the reverse acquisition. I know, I had the, uh, perverse and shameful pleasure of running BeOS on one of them for sport.
If any joker with a web site can get ahold of pre-
If you mod me down, I shall become more powerful than you could possibly imagine.
Well, according to MS, Windows has no problems supporting 32 processors for 32 bit software and 64 processors for 64-bit software. Given versions of windows are limited to a lower number of processors, though not cores. One processor is one processor regardless of cores by MS's licensing. Indeed you'll find XP Pro, while only supporting 2 processors, will happily run 2 dual core processors and see and use all 4 cores.
/. that Vista won't support OpenGL (http://slashdot.org/article.pl?sid=05/08/06/17725 1). Well it turns out this isn't just false, but is the exact opposite of the truth. Vista indeed supports OpenGL in three different ways:
/. story, you'd think they'd all but disabled hardware GL in their OS. As it stands nVidia has beta drivers with a GL ICD. I haven't tried them, but the release notes suggest it's a new ICD that work with the compositor. ATi's drivers don't have an ICD, though ATi claims to be working on it and says they'll have it for launch. Intel doesn't have any driver status for Vista on their website.
You have to remember that Windows is not static, they improve it all the time. They rolled out a 32-processor version back with Windows 2000. It's called Data Center Edition. You can't buy it over the counter, only from OEMs that make systems with tons of processors. You've likely never encountered it since it's fairly rare to see systems with that many processors. Generally you cluster smaller systems rather than get one large one. However there are cases where the big iron is called for, hence why HP sells them.
Also I think multiprocessing in the OS is less complicated than many people make it out to be. The OS isn't where the magic has to happen, it's the app. The OS already has things broken up for it in the form of threads and processes. A thread, by definition, can be executed in parallel. So the OS simply needs to decide on the optimum placement of all the threads it's being asked ot run on it's cores. Also, it doesn't have to stick with where it puts them (unless software requests a certain CPU), it can move them if there's reason to. The hard part is in the app, to break it up in to pieces that can be processed at the same time and to keep them all in sync.
My guess is that it's mostly FUD floated by anti-Windows people. There is, unfortunately, a lot of that going around. For example it was reported on
1) The method mentioned there, as an emulation that is limited to 1.4 and isn't that fast. Bonus is it works on any system with Vista graphics drivers, even if the manufacturer doesn't provide GL.
2) Old style ICD. This is the kind of driver used on XP today. This more or less takes over the display, and thus will turn off all the nifty effects while active. The bonus is there's little to update. However this is probably not going to be used because there's...
3) The new ICD. This provides full, hardware accelerated GL and is fully compatible with the shiny new compositing engine. For that matter, you can add any API you want via an ICD that works with the new UI.
So not only does the OS have the ability to support GL, it can do so better than XP can, because GL can be used in the same way as DX. However to read the
When it comes to Windows info, you do need to check sources, as with anything else. There's plenty of misinformation floating around. Often people who don't like Windows believe they know what they are talking about so post incorrect information.