Jihad needs scientists
in [Design]
|
From: Ken Smith on 20 Feb 2007 09:27 In article <ereron$8qk_010(a)s883.apx1.sbo.ma.dialup.rcn.com>, <jmfbahciv(a)aol.com> wrote: [......] >>The reason almost all PCs aren't dually is not because PCs >>can't be dually, it's because that's what the market wants. > >That's not the reason. Devices aren't multi-ported. To have >an effective multi-CPU general purpose system, all CPUs should >have hardware access to all devices. That is not true. You can have single ported devices in a multiprocessor system with no problem. Since the device is usually a physical thing, it can only do one thing at a time and is always slower than the processor. A well written OS can deal with this issue with no big problem. > Another limitation is >no PC systems are sold that can have multiple ttys connected to it. The PC I'm typing on can have 2 ttys connected. The one at work can have 4. This isn't the real problem. > >> >>Those who strive for more than mediocrity in their PC have >>been able to find duallies quite easily for a decade. > >But are the device drivers reentrant? If they aren't, the >multi-CPU systems aren't as useful as they could be. Reentrant drivers are not the issue when the hardware they connect to isn't. A well written OS will deal with it by letting one or the other CPU have control of the device while its operations are going on and make sure the other CPU is doing something elese useful. -- -- kensmith(a)rahul.net forging knowledge
From: Ken Smith on 20 Feb 2007 09:41 In article <52406$45da6760$cdd084bb$25290(a)DIALUPUSA.NET>, nonsense(a)unsettled.com <nonsense(a)unsettled.com> wrote: >Rich Grise wrote: >> On Mon, 19 Feb 2007 23:01:11 +0000, Ken Smith wrote: >> >>>nonsense(a)unsettled.com <nonsense(a)unsettled.com> wrote: >>> >>>>Ken Smith wrote: >>>> >>>>>nonsense(a)unsettled.com <nonsense(a)unsettled.com> wrote: >>>>> >>>>>>d.086(a)hotmail.com wrote: >>>>>> >>>>>> >>>>>>>Could you please terminate this thread. It's off topic and crossposted >>>>>>>to sci.physics, sci.chem, sci.electronics.design, sci.med The >>>>>>>discussion below is only about electronics design. Please start a new >>>>>>>thread in your own news group and give it a Subject heading >>>>>>>appropriate to the topic under discussion. Please no more 'Jihad needs >>>>>>>scientists'. It's offensive. >>>>>> >>>>>>That's nice. >>>>> >>>>>By posting that you did exactly the thing he was asking you not to do. I >>>>>really don't see why you did it after all he should get his way about what >>>>>happens on the usenet shouldn't he? >>>> >>>>Oh gee, did I do something wrong? >>> >>>Yes, you should be ashamed of your self for continuing to post into this >>>thread when you were asked by that very important person not to. Such >>>people need to have their every whim catered too. If not they may may pout >>>and that would be very bad, I think you would agree. >>> >> >> My newsreader has an "Ignore thread" menu option, but apparently it goes >> by actual threading, and not subject line. >> >> Good-Bye. >> Rich > >It seems the pouters are circling. I think I need more time >to contemplate what you're promoting here, Ken. This is such >a serious issue I don't want any possibility of getting it >wrong. Yes, it is certainly worthy of some serious thought. End of life issues are always complex and full of moral questions. Many people will argue about when the death of a thread occurs. This can be very hard if the thread has trollers and spam in it. When a thread dies of spam, posting activity continues long after the actual death. Trollers tend to stop very quickly when they sense that no-one will respond to their tripe. Most of those who have a religeous point of view, I assume, think of the thread as merely going to silicon heaven and resting there. Some would argue that with out the input of new postings, the thread is thrown into the deep abiss, but I assume this is a small minority. A small sect called "seeplusplus programmers" just forget the thread ever existed when they lose the pointer to it. The "lisp programmer" sect has a very unusual view. They believe that as long as the thread has references to its self, it will live forever. -- -- kensmith(a)rahul.net forging knowledge
From: Eeyore on 20 Feb 2007 09:41 jmfbahciv(a)aol.com wrote: > Another limitation is no PC systems are sold that can have multiple ttys > connected to it. You can have 4 serial ports. Possibly more. Graham
From: Ken Smith on 20 Feb 2007 09:42 In article <ereol0$8ss_011(a)s883.apx1.sbo.ma.dialup.rcn.com>, <jmfbahciv(a)aol.com> wrote: [....] >Tell me which newsgroup should be deleted. The poster didn't say. I think it was alt.the.big.whiners -- -- kensmith(a)rahul.net forging knowledge
From: Eeyore on 20 Feb 2007 09:47
Ken Smith wrote: > <jmfbahciv(a)aol.com> wrote: > [......] > >>The reason almost all PCs aren't dually is not because PCs > >>can't be dually, it's because that's what the market wants. > > > >That's not the reason. Devices aren't multi-ported. To have > >an effective multi-CPU general purpose system, all CPUs should > >have hardware access to all devices. > > That is not true. You can have single ported devices in a multiprocessor > system with no problem. Since the device is usually a physical thing, it > can only do one thing at a time and is always slower than the processor. > A well written OS can deal with this issue with no big problem. It'll probably do it better too. It makes no sense at all to hold up a fast CPU to negotiate I/O commands. Graham |