Transcript Towards the Fanless PC - Discobolus Designs, Home Page

Towards the Fanless PC
Bill Gervasi
Technology Analyst, Transmeta
Chairman, JEDEC Memory Parametrics
[email protected]
January 23-24, 2002
The New Multimedia PCs
What doesn’t fit?




MP3 music & DVD movies
100W per channel amplifier
Surround sound speaker system
PC fans, disks, etc. with 75 dB of
white noise
2
Market Effects

PC having trouble escaping the den



Limits applications for PCs



Can’t hook into main sound system
Can’t displace gaming stations
PCs not meeting government standards



Too noisy for family room or bedroom
Always-on strategies have failed
Especially in Europe
Too noisy, consume too much power
Office and POS impacted by noise
3
Why Are PCs So Noisy???
Fans everywhere!!!
Fan in the power supply
 Fans by the PCI/AGP cards
 Fans at the front of the box
 Fan on top of the CPU
 Fan on top of the graphics controller

4
5
Know Your Enemy
#2
#1
Public
Enemies
#3
#4
Wanted: Dead (only)
6
Fan Noise

And these
are just
the CPU
fans!!!
7
Why Do We Need Fans?

CPUs on runaway thermal path

Graphics controller overkill

Memory subsystems not well managed

Add-in cards with unknown wattage
requirements
8
First Worst Culprit: The CPU
9
Transistor Trends
Pentium is a trademark of Intel Corp.
10
CPU Power Trends
11
CPU Power Density, 2000-2010
12
… and the CPU
isn’t the only
power hog in
the system …
… while most subsystems
are stable, the graphics
controller challenges the
CPU for watts …
13
x86 PC Platform Power
Graphics
14
PC Graphics

2D & text essentially unchanged

Addition of video acceleration & data
types

3D explosion
Texturing, bumping
 Antialiasing

Out of control… !!!
15
PC Graphics Reality

Few features ever used


Wasted frame buffer performance


2D & text is still the dominant use
9.6 GB/s memory bandwidth for 2D???
AGP bus a power drain
16
Memory & Chipsets
17
Memory

Market just now shifting from 3.3V
SDRAM

Full size 5 ¼“ DIMMs, 3 slots

Does a mainstream PC need 1.5 GB???

No power management implemented

Thermal throttles enabled only when the
bandwidth is really needed
18
Chipsets

No power management

Inefficient buses with PLLs

“Soft peripherals” using power hungry
CPU instead of ultra low power DSPs

Polled mode peripherals burn power on
bus

Interrupting protocols (like USB) prevent
deep sleep modes
19
What About Other Sources of
Noise?

DVD or CD drives

Hard disk drives
20
Other Sources of Noise: DVD
Ricoh MP9060A-DP
The first thing we didn't like was a noisy
532EB(32x)).
work of the optical head (2 times louder than that of TEAC
As you know, loud
CD spinning is one of the major drawbacks of all CD-ROMs with
more than 24x. Here, thanks to the tight-fitting tray, nothing can be heard... but the
combine may not "like" some kinds of discs, in this case there begins strong vibration with some
noisy effects. …
AOpen DRW4624
Noise effects are practically the same as that of the Ricoh device. The construction of the tray's lid is not
ideal, so there is some unpleasant air whistle. The combine is not so sensible to the disc quality and balance.
It read low-quality discs more quietly and without so strong vibration. The combine did not overheat after it
had written 6 discs successively. The tray and the case were just a little warm.
Samsung SM-304
In this case noise effects were quite inaudible, the tray fitted tight. The optical head moved noiselessly. The
combine is not sensible to the disc quality (perhaps, it depends on the type of the tray). …
Toshiba SD-R1002
As for noise effects we can place this combine between Ricoh and Samsung. Since there installed the
standard tray, you can hear the "standard" air noise. The combine is not very sensitive to the disc quality,
though there is some light vibration. The tray's lid fits quite tight. The optical head moves noiselessly. …
Source:
http://www.digit-life.com/articles/dvdcdrwreview/
21
Other Sources of Noise: HDD
db(A)
22
What effect
has this trend had
on the PC market?
23
Desktop PCs are a Commodity

Margins are shrinking everywhere so OEMs are
relying upon other sources



Internet signup bounties (AOL, Earthlink)
Subscription services (Real Networks)
Software services (Quicken)

Press & Analysts are saying the “PC is dead”

Rapid technology advances have out-paced user
needs

Free CPU Cycles, Free GB, Free Bandwidth
24
What the world needs now…
efficient computing
ecoPC
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ecoPC Goals

No fans, no noise

Never needs to be
turned off

Utilize existing industry infrastructure

Lay out a new roadmap for the future

Cost competitive with BYO generic boxes
26
Today’s Product Differentiation
iMac
NetVista
iPAQ Desktop
DISCOVERY
Thin Client
Differentiated designs
– right idea but NO MASS MARKET
Prevents volume discount of infrastructure
27
What Do BYO Generic Boxes
Do Right?
$BOM  $BOM  $BOM
These things are dirt cheap
because they use standard
parts
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ecoPC: Segment Definition
Windows XP Based PC







Low Energy Consumption
 15Watt Typical, 20Watt Max
Low Cost of Acquisition
 Sub $800
Low Noise
 No fans, quiet drives = Silent PC
Low Space Consumption
 1” thick chassis
Low Cost of Operation
 Low Energy Bills from Power Efficiency
Low TCO Maintenance Costs
 Legacy Free
Low Cost of Manufacturing & Assembly
 Standard parts like BYO generic
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ecoPC -- Key Specs
Similar to today’s notebooks
Low power x86 CPU & energy efficient chipset
 Low power graphics, integrated or discrete
 Low power hard disk & optical drive
 RAM: DDR 2.5V
 External power supply
 No cooling fans
 Legacy free
 USB or Bluetooth keyboard & mouse
 Integrated LAN, modem, 802.11 wireless

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ecoPC -- Expansion
No extra bays; only external expansion
 Universal Flash slot: CF, Smart, Stick
 No PCI-class add-in slots
 Cardbus? Possibly…need a better
expansion strategy!
 1394 & USB suffer from abstraction
overhead
 Universal Docking with serialized host bus
 PCI or HyperTransport or 3GIO
 Merges out-of-box with native contact

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ecoPC Peripherals

New ecoPC specification needed
Acoustic limits defined
 Drives selected for low noise

DVD
 Hard disk


Power limits strictly enforced
Thermal/power sensors prevent violation
 ecoPC certification and logo

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ecoPC Processing Units
On Demand processing

Monitor system activity and shut off unused execution
units

Scale operational frequency on application demand

E.g., LongRunTM & PowerNow!TM

Utilize every microsecond that power is being burned

Offload interruptions to remote low power units (e.g.,
DMA units, DSPs)
LongRun is a trademark of Transmeta Corp.
PowerNow! is a trademark of AMD Corp.
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Power = CV2f%
Factors:
 Capacitance (C)
 Voltage (V)
 Frequency (f)
 Duty cycle (%)
 Power states
Keys to mobile
design:

Reduce C and V

Match f to demand

Minimize duty cycle

Utilize power states
34
ecoPC CPU

Low Transistor Count CPU
Seldom executed instructions in software
 Run time optimization


Scaleable operating frequency and
voltage

Integrates smart memory controller

Utilize every powered microsecond
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ecoPC Graphics

Shuts down unused pipes




Avoid unnecessary operations



2D, 3D, video
Rendering engines
Slows memory during screen refresh
Scatter-gather DMA using SMA
Focal point prioritized rendering resolution
Thermal limits switch rendering style

Reduce rendering quality of low priority objects
36
ecoPC Memory
SDR  DDR I  DDR II
3.3V  2.5V  1.8V

JEDEC roadmap triples GB/s/W with
each generation



Power reduction of 30%
Bandwidth doubles
Move from 3 DIMMs to 2 SO-DIMMs

Sufficient capacity, higher performance,
lower power, and no evil PLLs
37
Power: DDR II vs DDR I vs SDR
Four times the
bandwidth yet
half the power!
DDR533
“DDR II”
DDR333
“DDR I”
PC133
Relative GB/s per Watt
38
Low Power DRAM Futures

Aggressive use of power states (CKE)

Increased refresh flexibility



Temperature compensated refresh
Partial array refresh
Reduced page size

Fewer cells discharged/recharged
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ecoPC DRAM Timing
Relaxed mode timing

Comprehend effects of DLL


Aligns data to clock on reads… only!
Use DRAM in low performance mode while
DLL is not locked

Accommodate wide range on clock to strobe
CK
DQS
>  tDQSCK
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Strobe to Data is Fixed
DQS
 tDQSQ
ODD
DATA
ODD
DATA
ENABLE
L
even
odd
DLL has no effect on data to
strobe timing, therefore DRAM can
be used while DLL not locked!
8
EVEN
DATA
DATA
H
DQS
EVEN
DATA
ENABLE
41
Why Relaxed Mode Timing?
Utilize the DLL/PLL lock times
2-100 ms per power management event
 Allows much finer granularity on control
 Better utilization of powered on state


Switch back to full performance mode
after the DLL/PLL lock

This concept can be applied to any
locked bus
42
Building
the
ecoPC
43
Today’s PC
44
Cooler CPU
45
Integrated Graphics
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Efficient Memory
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Eliminate PCI
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No Fans
49
Slimline Case
50
ecoPC
A New
Standard
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Conclusions

Thermals of today’s PCs too
high


Use of fans to cool PCs restricts
market growth
ecoPC standard definition
needed to expand the PC
market
Low heat
 No noise
 Performance on demand

52
Summary

We have the basic components
for the ecoPC now from notebook
market

Future focus on high computing
efficiency will increase
performance without
compromising power or noise
limits
53
Thank You
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