Why are PC sales declining ? (Skybuck thoughts on it too)

  • Thread starter Thread starter Skybuck Flying
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I can't say I've run any tests, but I don't see how they are getting
more processing other than adding to the cache sizes. Pipelining and
speculative execution should have been mature some 10 years ago. What
exactly is left to improve on?
Click to expand...

I had to think about that since I largely agree. Although register
colouring and other tricks are comparatively recent as a refinements
that keep the execution pipeline from stalling so easily.

Taking CPUs I have most experience of tormenting:

9630 i7-3770K TDP 77W @ 3.5GHz (peak 3.9GHz) and 4 x 2 cores
8962 i7-2700K TDP 95W @ 3.5GHz and 4x2 cores
7130 i5-3570K TDP 77W @ 3.4GHz (peak 3.8GHz) and 4 cores
6402 i5-2500K TDP 95W @ 3.3GHz and 4 cores
2962 Q6600 TDP 105W @ 2.4GHz and 4 cores

Back of the envelope calculations suggest that the most recent benchmark
improvements have come from on demand turbo boost - that is the
difference between 3770 & 2700 and 3570 & 2500 can be largely explained
by the 10% faster clock when asked to work really hard.

And even my old Q6600 with a toasty 105W TDP if it could be scaled to
the same hardware spec as the new CPU would improve by the ratio of the
clock speeds and a factor of two for hyperthreading (optimistic).

2962 x (3.9/2.4) = 4813 and double that for hyperthread = 9626

Suspiciously close agreement! So arguably they are gaming the standard
benchmarks now to make new chips look more attractive. Underlying
performance is rather similar except when heavily loaded by optimally
designed parallel algorithms designed to use all the cores at once.
That assumption is a big one! The study I read said the turn was less
than 4 CPUs. Many apps just won't see much improvement with even two
processors. The observed increase in performance is because the OS
needs elbow room, so a second processor helps get it out of the way of
the user app.
Click to expand...

It depends on the application. Some things benefit whereas others don't.
Hyatt did a lot of work on optimising chess search algorithms on
multiple processors (and that is a tricky algorithm to parallelise).

N_CPUS 1 2 4 8 16
Naive 1 1.8 3 4.1 4.6
EVP 1 1.9 3.4 5.4 6
DTS 1 2 3.7 6.6 11.1

Taken from his paper
http://www.cis.uab.edu/hyatt/search.html

Naive is typical of what happens if you try and parallelise without
thinking very carefully about the bottlenecks and DTS is more typical of
what you get with a streamlined optimised multiprocessor algorithm.

Most decent multicore code is somewhere between these two extremes ~ EVP
where you do OK on up to 4 cores.
I'm taking a look at the combined drives now. I'm not going to pay an
arm and a leg for one. I can get a SSD for under $200 that is bigger
than what I have now. A combined drive should be close to $100 I am
thinking.
Click to expand...

I found the Samsung drives performed better on incompressible data which
was important to me.
 
Any of you like Windows 8? I feel zero urge to install it.
Click to expand...


Yes, I like it fine, best of both worlds, Win 7 and Win 8 all in one
with classic shell./
I use both intrefaces as required, Like the speed and features, Like
learng new OS's ( I'm 80), keeps me young and informed.

Regards, Rene
 
Robert said:
If you're using Windows, the "Pro" versions of Vista/Win7/Win8 allow
you to use XP Mode, which is a canned 32-bit XP VM, for both 32 and 64
bit versions of the OS. You can do the same thing with a bit more
effort on other systems.
Click to expand...

I don't think WinXP Mode works on Windows 8.

Windows 8 blacklists Windows Virtual PC, so you can't install it.
(Well, you can install it, but you get a dialog when you go to run it.)
I doubt you can install VPC2007 either. On Windows 8, the available
Microsoft solution is Hyper-V, and that won't install without SLAT (EPT).
(Hyper-V was included on my copy of Windows 8, but it refused to install.)
And even if you install Hyper-V, chances are the WinXP Mode VM won't
run there.

WinXP Mode works in Windows 7. At least we know that works.

And it didn't have to be done that way. Someone at
Microsoft was overly clever. I wish I could figure
out their thinking sometimes. (It reminds me of a few
articles recently, where the article authors dreamed that
Microsoft cared what customers thought. Hilarious. What
comes out of Microsoft, in terms of feature set, is
pure "corporate randomness". Opposing forces within
the company crunch together, and the waste products
of the collision, are what we buy.)

Paul
 
Any of you like Windows 8? I feel zero urge to install it.
Click to expand...

I had trouble with it during the first 3 hours but
then realized my desktop machine didn't have a
touch screen.
 
ToolPackinMama said:
Any of you like Windows 8? I feel zero urge to install it.
Click to expand...

The problem is, "like" is too strong a word.

It's operating status here, is it's about as
useful as one of my Linux LiveCDs, and used about
as often. No Microsoft account. Never been in the App Store.
Oh my.

I used ClassicShell on the Preview versions, but for
the actual bought version, it remains in pristine glory,
warts and all.

Paul
 
Somewhere on teh intarwebs Jeff Liebermann wrote:
[...]
I'm still using PIII machines for weather stations and data loggers.
The main attraction is low power consumption. I could do better with
a modern SBC, but I already had the working machines.
Click to expand...

I have a bunch of old IBM ThinkPads equipped with Pentium M CPUs that use
very little power yet are powerful - preferably R40/51s, they're quite
common, cheap and reliable.

(Use R52s if you want to load up on RAM as they use DDR2, much cheaper than
the former's DDR. The T-series are thin'n'light and, as such more prone to
failure with age. Either due to planar flexing or due to the fans being so
thin / hi-revving.)

Just my 2c. I have a Compaq SFF desktop that uses a PIII 1.13GHz Tualatin
(2GB RAM) and I'm amazed at how slow it is compared to one of the
above-mentioned ThinkPads. So much so that it's due to go to the dump as
it's worth next-to-nothing. I've not even had takers when I offered it
free - except for people who wanted to rob the RAM and sell it on ebay. I
can do that, I'd just rather see it getting used. <shrug>
--
/Shaun.

"Humans will have advanced a long, long, way when religious belief has a
cozy little classification in the DSM."
David Melville (in r.a.s.f1)
 
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