The Marketing of MegahertzThere is a battle being fought at this very moment
over the mighty megahertz measuring stick used by both Transmeta and Intel. Each company
uses this one aspect of measuring a systems performance to help convey the
performance of their products to the end consumers.
At face value this would seem to be an infallible method of comparison.
Megahertz is a number (or more correctly a unit of measurement) so it either
is, or isn't accurate. There is no need, nor is there room for
interpretation - a processor either operates at a specific value of MHz or it
does not. Right? Well not always...
For instance, right now I'm typing this article on a TM5600 Crusoe powered NEC notebook that I know for certain is operating
at 600MHz (or more precisely 592.66MHz). Transmeta's power management utility, Long Run is on,
but I've configured it so that the notebook operates at full
tilt. The program itself gives me a visual clue as to the general
operating characteristics as I type each key, or move the cursor around. But to
really drive the point home that this computer is operating at 600MHz (or precisely 592.66MHz)
I need only run a program called WCPUID/CLK - a real time clock
checker.
I can run
this test with the NEC notebook running on its internal batteries, or while
connected to the wall via the AC adapter and the results will be the same. I can
even run this program on my old 366MHz Celeron based Acer notebook to see that
it is indeed running at 366MHz, whether plugged into the wall or while operating
on its batteries.
Where recent conflicts have begun to arrive are with Speed Step enabled Intel
mobile Pentium III processors.
As with most conflicts in the tech industry, this one is
completely marketing driven and has to do with the way some
notebooks are represented to the consumer, and specifically how they compare to
Crusoe-based notebooks.
Intel offers a range of fixed speed,
mobile PIII processors that operate at between 400MHz and 500MHz. All other
current mobile PIII processors operate with a technology called Speed Step. In
Intel's own words, what Speed Step enables the mobile PIII to do is "operate in
two performance modes - maximum performance mode for near desktop performance,
and battery optimized performance mode for lower power consumption and improved
battery life."
Essentially, when
the notebook is in "maximum performance mode" (such is the case when connected to AC power) the processor by default
operates at the full clock speed. When the notebook is operating in mobile
mode, or "battery optimized mode" (such is the case when relying only on the internal
battery), it will by default, operate at a lower clock speed to conserve electricity - a
la Speed Step. See the conflict?
When the notebook is operating in "battery optimized mode" (mobile mode) is
when it is actually acting like a notebook, but at a substantially lower clock
speed than it is generally referred to. Of course, a notebook with a mobile PIII
can have Speed Step manually overridden so it will operate at the "maximum
performance mode" while just on battery power, but this conflicts with Intel's
notion of mobile mode, and comes with a sacrifice to battery life.
If you're confused don't worry, there is a lot of
emphasis being put on word play here. Hopefully the following chart will clear
things up, and underline the difference in default
clock speeds for Speed Step enabled PIII processors operating
under AC and battery alone.
| Processor |
AC power |
Battery |
| Fixed-Speed PIII |
| PIII |
500MHz |
500MHz |
|
450MHz |
450MHz |
|
400MHz |
400MHz |
| Normal PIII Mobile |
| PIII Mobile |
1.26GHz |
800MHz |
|
1.0GHz |
700MHz |
|
900MHz |
700MHz |
|
850MHz |
700MHz |
|
800MHz |
650MHz |
|
750MHz |
600MHz |
|
700MHz |
550MHz |
|
650MHz |
500MHz |
|
600MHz |
400MHz |
| Low Voltage (LV) Mobile PIII |
| LV PIII |
866MHz |
533MHz |
|
750MHz |
500MHz |
|
700MHz |
500MHz |
|
600MHz |
500MHz |
| Ultra Low Voltage (ULV) Mobile PIII |
| ULV PIII |
700 |
300MHz |
|
600 |
300MHz |
|
500 |
300MHz |
Of this list, the LV and ULV Mobile PIII processors are
most directly comparable to Crusoe in terms of the applications and types of
notebooks they will find themselves into. Generally speaking the ULV, and LV
types are destined for sub 6lb notebooks and subnotebooks. The vast majority of
the normal PIII mobile processors find their way into 6lb or heavier notebooks
and are not directly competing with the Crusoe processor market. Regardless
of type or die size (0.18 or 0.13 micron) each Intel processor equipped
with Speed Step operates by default, at a lower "battery-optimized mode" clock
speed.
Additionally, since
Transmeta's Crusoe processors
are equipped with an onboard north bridge chipset, directly comparing
the power consumption of the Crusoe chips to that of the Mobile PIII
is somewhat inaccurate, especially when notebook power consumption is concerned.
Ideally, this type of notebook level comparison would see Crusoe pitted
against the PIII processor and its' north bridge chipset. That chipset
alone can account for anywhere between 1-3 extra Watts of power consumption in the
Intel system.
As we said, the differences are primarily marketing
driven, and the terms of conflict are almost to the level of legal specifics,
but if you are seeing comparisons between these two processors it is important
to keep these points in mind. After all, if notebook is meant to be used as
a mobile platform then Speed Step seems to be more of a handicap than an
advantage. Sure it scales the processor back into a "battery optimized mode,"
but this
also scales back the
performance of the machine as well. With that
in mind, there are a couple of options for the consumer to consider;
side with Crusoe-based notebooks that operate at their listed frequencies, or go
for a 850MHz mobile PIII and save a few bucks over the 1.0GHz
model - both scale back to 700MHz when in "battery optimized mode."
In this regard, Speed Step appears to function as both a technology for
Intel-based notebooks and as a marketing tool. While it would be nice to see the
notebooks classed by only their mobile speeds this seems unrealistic. Faced with
no other alternative it is good to remember that in terms of power consumption
and MHz, the differences are not always what they appear to be at face
value.