x86 vs The World...

Many years ago when dinosaurs roamed the earth, there was the x86 and 
then there were the viable contenders.  That list was headed by MIPS and 
PowerPC with others as "also ran".  With time none of these 
architectures kept up with the megalith Intel's forces and the x86 took 
over the world resulting in the extinction of the dinosaur.

In more recent times the focus has shifted from raw power (so essential 
  in the times of dinosaurs) to low power as dictated by the smaller 
size and battery operation of new devices (think mammals).  Now the 
power guzzling of the x86 line is creating global warming and 
threatening our very existence.  But today's processor on the white 
charger is the ARM, not PowerPC or MIPS.

Was it inevitable that these lesser architectures take second fiddle to 
the ARM or was it just a fluke of marketing or corporate mismanagement 
that led to their being relegated to the processing hall of fame?

Is there any compelling technical reason for the emergence of the ARM 
over other non-x86 processors?

-- 

Rick

rickman <gnuarm@gmail.com> writes:
> [...]
> Is there any compelling technical reason for the emergence of the ARM
> over other non-x86 processors?

I don't know if it's a reason, but most processor vendors provide IP
_and_ fab. ARM is one of the relatively few that just provide IP and
allow other companies to handle the fab.

Perhaps this, along with reasonable IP licensing, is responsible (in
addition to being a pretty decent processor)?
-- 
Randy Yates
Digital Signal Labs
http://www.digitalsignallabs.com

rickman wrote:

> [ ... ]  But today's processor on the white
> charger is the ARM, not PowerPC or MIPS.
> 
> Was it inevitable that these lesser architectures take second fiddle to
> the ARM or was it just a fluke of marketing or corporate mismanagement
> that led to their being relegated to the processing hall of fame?
> 
> Is there any compelling technical reason for the emergence of the ARM
> over other non-x86 processors?

I understand that a lot of Chinese development for their own use is based on 
MIPS.

	Mel.

On 2014-06-04, rickman <gnuarm@gmail.com> wrote:
> Many years ago when dinosaurs roamed the earth, there was the x86 and 
> then there were the viable contenders.  That list was headed by MIPS and 
> PowerPC with others as "also ran".  With time none of these 
> architectures kept up with the megalith Intel's forces and the x86 took 
> over the world resulting in the extinction of the dinosaur.
>
> In more recent times the focus has shifted from raw power (so essential 
>   in the times of dinosaurs) to low power as dictated by the smaller 
> size and battery operation of new devices (think mammals).  Now the 
> power guzzling of the x86 line is creating global warming and 
> threatening our very existence.  But today's processor on the white 
> charger is the ARM, not PowerPC or MIPS.
>
> Was it inevitable that these lesser architectures take second fiddle to 
> the ARM or was it just a fluke of marketing or corporate mismanagement 
> that led to their being relegated to the processing hall of fame?
>

ARM has a massive advantage going for it: a _massive_ hobbyist and
low end embedded systems ecosystem which means it's been easy for a
_long_ time for individuals to use this architecture for their own
personal projects.

There's nothing hobbyist related in the PowerPC world and the only
MIPS architecture variant I am aware of which is hobbyist suitable
is the PIC32MX.

What people forget in this next-quarter driven world is that today's
hobbyists and/or students are tomorrow's decision makers. That doesn't
help you meet next quarter's target, but it does mean that those
people will be starting to make recommendations to their new employers
in the future.

Those people know ARM from their own projects and they know the
ecosystem. I'll let you work out what happens next. :-)

> Is there any compelling technical reason for the emergence of the ARM 
> over other non-x86 processors?
>

At the technical level, ARM is a very elegant architecture. Over the
last few days, as part of a hobbyist project, I've been going some bare
metal work on x86 for the first time in a number of years and I had
forgotten how utterly crap the x86 architecture is (at bare metal level)
when compared to ARM.

The ARM architecture is very expressive when compared to MIPS, but
I know nothing about PowerPC. I wonder how the code density of the
various architectures compares.

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world

On 05.6.2014 г. 02:08, rickman wrote:
> Many years ago when dinosaurs roamed the earth, there was the x86 and
> then there were the viable contenders.  That list was headed by MIPS and
> PowerPC with others as "also ran".  With time none of these
> architectures kept up with the megalith Intel's forces and the x86 took
> over the world resulting in the extinction of the dinosaur.
>
> In more recent times the focus has shifted from raw power (so essential
>   in the times of dinosaurs) to low power as dictated by the smaller
> size and battery operation of new devices (think mammals).  Now the
> power guzzling of the x86 line is creating global warming and
> threatening our very existence.  But today's processor on the white
> charger is the ARM, not PowerPC or MIPS.
>
> Was it inevitable that these lesser architectures take second fiddle to
> the ARM or was it just a fluke of marketing or corporate mismanagement
> that led to their being relegated to the processing hall of fame?
>
> Is there any compelling technical reason for the emergence of the ARM
> over other non-x86 processors?
>

Power architecture is very much alive, just check what Freescale are
making.

The reason why the most popular architectures are crippled - x86
is simply a mess, ARM is better but just has too few registers
to be a viable load/store architecture - is not commercial.

Someone somewhere just makes sure most of the world uses - and
is familiar with - the crippled architectures while the best ones
(power is the best of those I have seen - by a margin, followed
by MIPS) are reserved for more critical areas where it matters.

Dimiter

------------------------------------------------------
Dimiter Popoff, TGI             http://www.tgi-sci.com
------------------------------------------------------
http://www.flickr.com/photos/didi_tgi/sets/72157600228621276/

Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> writes:
> forgotten how utterly crap the x86 architecture is (at bare metal level)
> when compared to ARM.

I've heard (maybe someone else knows specifics) that x86 is much better
than ARM with regard to things like predictable ordering of memory
operations in multicore systems.

On 05/06/14 01:08, rickman wrote:
> Many years ago when dinosaurs roamed the earth, there was the x86 and
> then there were the viable contenders.  That list was headed by MIPS and
> PowerPC with others as "also ran".  With time none of these
> architectures kept up with the megalith Intel's forces and the x86 took
> over the world resulting in the extinction of the dinosaur.
> 

The other architectures never fully died out - but they were relegated
to more niche markets.  There are lots of MIPS processors around,
especially in network equipment.  PowerPC turns up in high-end
microcontrollers such as in engine control, and IBM Power chips are
popular in big iron computers (as are Sparc's).  But they can't get the
economies of scale needed for competing in the mass market.

> In more recent times the focus has shifted from raw power (so essential
>  in the times of dinosaurs) to low power as dictated by the smaller size
> and battery operation of new devices (think mammals).  Now the power
> guzzling of the x86 line is creating global warming and threatening our
> very existence.  But today's processor on the white charger is the ARM,
> not PowerPC or MIPS.
> 
> Was it inevitable that these lesser architectures take second fiddle to
> the ARM or was it just a fluke of marketing or corporate mismanagement
> that led to their being relegated to the processing hall of fame?
> 
> Is there any compelling technical reason for the emergence of the ARM
> over other non-x86 processors?
> 

I think there are a mix of reasons - some technical, some non-technical.

The x86 ISA is crap.  It was viewed as limited and old-fashioned the day
it was created, and the IBM engineers designing the first PC wanted
nothing to do with it (they picked the 68000).  But the chip was
relatively cheap, and the 8-bit bus needed meant cheaper memory and main
boards, so the PHB's pushed it as the cpu for the IBM PC.  Fast-forward
to today and we have fantastic implementations of the same crap ISA.
(amd64 is somewhat better, but still not a nice ISA compared to MIPS,
PPC, or ARM.)  If the same clever folks at Intel had used the same time
and resources on making a better implementation of MIPS or PPC, we would
have faster, cheaper and lower-power cpus in the mainstream.

ARM were the right people, at the right time, with the right deals.  The
original ARM processor was a very nice design - it was done by smart
folk who looked at available processors, and thought of a better way to
do make a cpu.  It was low-power and low-size from the beginning.  And
because they didn't have a fab themselves, it was a relatively simple
matter to make the core as an IP for other manufacturers.  The ISA
itself is pretty good.  It is arguably not the best - generations of
Thumb and other instruction sets attest to that - but it is pretty good,
and ARM have done a good job of moving it forward.

MIPS is a bit of a sad story.  The ISA is excellent - it is a very
elegant processor.  But it has suffered commercially as a result of
competition with the x86 market, betrayal by Microsoft on the Windows NT
platform, and a series of owners of varying success.  For example, they
were bought by Silicon Graphics when they were struggling financially
and SG was a heavy MIPS user.  But then SG found that it gave more value
for money to put Intel chips in their workstations than to put their own
MIPS devices in the systems.  MIPS have always been popular in
networking equipment - they are very good at pushing data around, and
have small and low-power cores that work well in SOCs.  They used to be
significant in the mobile telephone market, and are heavily used in
set-top boxes, Bluray players, etc.

Unfortunately, MIPS have failed in the microcontroller market - despite
making cores that are highly competitive with ARM Cortex across the
range, and having decades of lead in the 64-bit class.  MIPS-based
devices tend to sell in very large quantities but to only a few
customers - the mass of developers out there simply don't know about
them, and can't get the chips or the information (companies that make
MIPS-based SOCs often have minimum order quantities in the 100,000
range).  They made an attempt with Microchip - but they were perhaps the
worst possible partner.  Microchip are very popular with small hobby
users - but that gives them a reputation of /only/ being for small hobby
users, and their other microcontrollers have a well-justified reputation
for having weird and painful cpu architectures and often very poor
tools.  (Microchip have many good points too - I'm just talking about
the cpu cores here.)  So the PIC32 is assumed to be another in the line
of bizarre Microchip-specific cores, and the decision to make the free
tools limited in optimisation (rather than the more common space
limitations) means that people trying them find the chips to be very slow.

So while most ARM licensees could swap out their Cortex cores with
corresponding MIPS cores and get similar prices, performance, and power,
and similar tools (gcc is the most common compiler for both platforms),
MIPS has missed the boat.

David Brown <david.brown@hesbynett.no> wrote:
> They made an attempt with Microchip - but they were perhaps the
> worst possible partner.  Microchip are very popular with small hobby
> users - but that gives them a reputation of /only/ being for small hobby
> users, and their other microcontrollers have a well-justified reputation
> for having weird and painful cpu architectures and often very poor
> tools.

Microchip also makes very buggy chips which doesn't help. As for the 
cores used, they just feel outdated. The M4K core used in the PIC32MX 
looks like it was designed to be a competitor to the ARM7TDMI, while the 
M14K feels like a reaction to the Cortex-M3, just without the elegance. 
You still need assembly glue or nonstandard compiler extensions. 
Meanwhile the competition has moved on to the M4F with floating-point 
support.

On a more positive note, MIPS recently launched release 6 of the 
architecture, which looks very interesting. It breaks compatibility in a 
major way - many less-used instructions have been removed to free opcode 
space, and the old fan-favourite delay slot instruction is also gone.

-a

David Brown wrote:

[ ... ]
> [MIPS] made an attempt with Microchip - but they were perhaps the
> worst possible partner.  Microchip are very popular with small hobby
> users - but that gives them a reputation of /only/ being for small hobby
> users, and their other microcontrollers have a well-justified reputation
> for having weird and painful cpu architectures and often very poor
> tools.  (Microchip have many good points too - I'm just talking about
> the cpu cores here.)  So the PIC32 is assumed to be another in the line
> of bizarre Microchip-specific cores, and the decision to make the free
> tools limited in optimisation (rather than the more common space
> limitations) means that people trying them find the chips to be very slow.

A little awkward too that Microchip produced a PIC32 evaluation board that 
wouldn't connect easily with anything except Microchip extension boards.  
The captive boards + captive compilers really limited the things that anyone 
would try to do.

	Mel.

Dimiter_Popoff wrote:

> On 05.6.2014 г. 02:08, rickman wrote:
> > Many years ago when dinosaurs roamed the earth, there was the x86 and
> > then there were the viable contenders.  That list was headed by MIPS and
> > PowerPC with others as "also ran".  With time none of these
> > architectures kept up with the megalith Intel's forces and the x86 took
> > over the world resulting in the extinction of the dinosaur.
> >
> > In more recent times the focus has shifted from raw power (so essential
> >   in the times of dinosaurs) to low power as dictated by the smaller
> > size and battery operation of new devices (think mammals).  Now the
> > power guzzling of the x86 line is creating global warming and
> > threatening our very existence.  But today's processor on the white
> > charger is the ARM, not PowerPC or MIPS.
> >
> > Was it inevitable that these lesser architectures take second fiddle to
> > the ARM or was it just a fluke of marketing or corporate mismanagement
> > that led to their being relegated to the processing hall of fame?
> >
> > Is there any compelling technical reason for the emergence of the ARM
> > over other non-x86 processors?
> >
>
> Power architecture is very much alive, just check what Freescale are
> making.

PowerPC in quite a few of the Freescale parts is designed to work
in bad environments both electrical and physical.  (automotive
engine controllers, and bad environment applications like process
control.

w..