POV-Ray : Newsgroups : povray.off-topic : Three guesses why : Re: Three guesses why Server Time
30 Jul 2024 02:28:18 EDT (-0400)
  Re: Three guesses why  
From: Darren New
Date: 22 Jun 2011 18:12:23
Message: <4e0268c7$1@news.povray.org>
On 6/22/2011 14:09, Orchid XP v8 wrote:
> windows stop repainting,

All of them? Or just explorer windows?  Because none of that stuff happens 
with me.  Maybe you have something installed that goes compute-bound or 
something when you mount a disk.

> I'm not sure "the entire PC stops working every time you touch the CD drive"
> is what I'd call an "edge case", but whatever...

Clearly it doesn't "stop working."  Try opening the task manager and 
watching the chart scroll when you put something in the CD drive.

> Then again, the advantage of a vanilla SSD is that it works with everything.

Exactly, yes.

>>> Warp's original comment was that partitioning an arbitrary problem
>>> such that
>>> you gain parallel speedup is probably impossible "in practise".
>>
>> I wouldn't be surprised if it was mathematically impossible in theory,
>> either.
>
> Well, no, the search space is presumably finite (although absurdly vast), so
> theoretically it's trivial.

Hmmm. Maybe, yeah, if you tried every possible rearrangement of opcodes sort 
of thing. But that assumes you can tell that the rearranged opcodes will 
have the same effect, which again is impossible.

I.e., the number of ways you can chop up the problem is finite, but the 
number of *wrong* ways to chop up the problem is non-zero.

>>> The other thing I've thought about is having multiple heap areas and
>>> tracking pointers between them. If you could arrange it so that all the
>>> garbage is in one heap chunk, you can just drop the whole chunk rather
>>> than
>>> doing complex processing over it. However, that's not easy to achieve in
>>> general.
>>
>> That's called semi-space garbage collection.
>
> Wikipedia's description of "semi-space GC" seems to be "2-space GC".

Well, you're either talking about generational heaps, semi-space heaps, or 
separate heaps that might have roots in other heaps, in which case it's the 
same as a generational heap technologically-speaking.

>
>>>> Yep. That's why NUMA is getting more popular and such.
>>>
>>> Only for supercomputers.
>>
>> The Opteron is a supercomputer?
>
> How many desktop PCs contain an Opteron?

http://sites.amd.com/us/business/products/desktop/Pages/hp.aspx

Come on now. That wasn't even difficult.

> Desktop PCs have had non-uniform memory access times for decades now. But
> currently, they all *pretend* to have uniform memory.

Well, except to the OS.  Applications pretend they all have contiguous 
memory addresses, too.

-- 
Darren New, San Diego CA, USA (PST)
   "Coding without comments is like
    driving without turn signals."


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