Towards the Fanless PC

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Towards the Fanless PC

• Bill Gervasi
• Technology Analyst, Transmeta
• Chairman, JEDEC Memory Parametrics
• bilge_at_transmeta.com

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The New Multimedia PCs

• What doesnt fit?

• MP3 music DVD movies
• 100W per channel amplifier
• Surround sound speaker system

• MP3 music DVD movies
• 100W per channel amplifier
• Surround sound speaker system
• PC fans, disks, etc. with 75 dB of white noise

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Market Effects

• PC having trouble escaping the den
• Too noisy for family room or bedroom
• Always-on strategies have failed
• Limits applications for PCs
• Cant hook into main sound system
• Cant displace gaming stations
• PCs not meeting government standards
• Especially in Europe
• Too noisy, consume too much power
• Office and POS impacted by noise

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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

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Know Your Enemy
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PublicEnemies
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Wanted Dead (only)
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Fan Noise

• And these are just the CPU fans!!!

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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

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First Worst Culprit The CPU
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Transistor Trends
Pentium is a trademark of Intel Corp.
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CPU Power Trends
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CPU Power Density, 2000-2010
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and the CPUisnt the onlypower hog inthe
system
while most subsystems are stable, the graphics
controller challenges the CPU for watts
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x86 PC Platform Power
Graphics
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PC Graphics

• 2D text essentially unchanged
• Addition of video acceleration data types
• 3D explosion
• Texturing, bumping
• Antialiasing
• Out of control !!!

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PC Graphics Reality

• Few features ever used
• 2D text is still the dominant use
• Wasted frame buffer performance
• 9.6 GB/s memory bandwidth for 2D???
• AGP bus a power drain

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Memory Chipsets
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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

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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

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What About Other Sources of Noise?

• DVD or CD drives
• Hard disk drives

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Other Sources of Noise DVD
Ricoh MP9060A-DP The first thing we didn't like
was a noisy work of the optical head (2 times
louder than that of TEAC 532EB(32x)). 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/
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Other Sources of Noise HDD
db(A)
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What effecthas this trend hadon the PC market?
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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

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What the world needs nowefficient
computingecoPC
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ecoPC Goals

• No fans, no noise
• Never needs to beturned off
• Utilize existing industry infrastructure
• Lay out a new roadmap for the future
• Cost competitive with BYO generic boxes

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Todays Product Differentiation
iPAQ Desktop
DISCOVERY Thin Client
NetVista
iMac
Differentiated designs right idea but NO MASS
MARKET Prevents volume discount of infrastructure
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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 DefinitionWindows 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 todays 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? Possiblyneed 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

• Keys to mobile
• design
• Reduce C and V
• Match f to demand
• Minimize duty cycle
• Utilize power states

• Factors
• Capacitance (C)
• Voltage (V)
• Frequency (f)
• Duty cycle ()
• Power states

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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
• 2D, 3D, video
• Rendering engines
• Slows memory during screen refresh
• Avoid unnecessary operations
• Scatter-gather DMA using SMA
• Focal point prioritized rendering resolution
• Thermal limits switch rendering style
• Reduce rendering quality of low priority objects

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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

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Power DDR II vs DDR I vs SDR
Four times the bandwidth yet half the power!
DDR533 DDR II
DDR333 DDR I
PC133
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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
gt ? tDQSCK
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Strobe to Data is Fixed
DQS
? tDQSQ
even
odd
ODDDATA
DLL has no effect on data to strobe timing,
therefore DRAM can be used while DLL not locked!
L
ODDDATAENABLE
8
EVENDATA
DATA
H
DQS
EVENDATAENABLE
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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

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Buildingthe ecoPC
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Todays PC
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Cooler CPU
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Integrated Graphics
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Efficient Memory
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Eliminate PCI
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No Fans
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Slimline Case
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ecoPC
A NewStandard
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Conclusions

• Thermals of todays 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

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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

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Thank You