ddr sdram the memory of choice for mobile computing
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DDR SDRAM The Memory of Choice for Mobile Computing. Bill Gervasi Technology Analyst, Transmeta Corporation Chairman, JEDEC Memory Parametrics [email protected]. Topics to Cover. Market Segments & Fragments Mobile Design Architectures DDR and SDR Power Analysis DDR SO-DIMM Details. - PowerPoint PPT PresentationTRANSCRIPT
DDR SDRAMDDR SDRAMThe Memory of ChoiceThe Memory of Choicefor Mobile Computingfor Mobile Computing
Bill GervasiBill Gervasi
Technology Analyst, Transmeta CorporationTechnology Analyst, Transmeta Corporation
Chairman, JEDEC Memory ParametricsChairman, JEDEC Memory Parametrics
[email protected]@transmeta.com
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Topics to CoverTopics to Cover
Market Segments & FragmentsMarket Segments & Fragments
Mobile Design ArchitecturesMobile Design Architectures
DDR and SDR Power AnalysisDDR and SDR Power Analysis
DDR SO-DIMM DetailsDDR SO-DIMM Details
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Segments & FragmentsSegments & FragmentsServers
Workstations
PC Segment 2
PC Segment 1
PC Segment 0
Mobile
Graphics
2H99 1H00 2H00 1H01
PC100 DDR
PC100 DDR
PC100 Rambus DDR
PC100
PC100
PC66 PC100 DDR
PC133
PC133
SS167 DDR (x16 and x32)
DDR
2H01
DDR
PC133
PC133
PC133
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RAM EvolutionRAM Evolution
320MB/s400MB/s
1000MB/s
2100MB/s
MainstreamMemories
FPEDO
SDR
DDR
Simple,incrementalsteps
DDR II3200MB/s
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Mobile DesignsMobile Designs
Two Sockets, T-stubTwo Sockets, T-stub 133MHz clock (for now)133MHz clock (for now) 2.1GB/s transfer (for now)2.1GB/s transfer (for now)
Mobile
Memory
Controller
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Butterfly SO-DIMMsButterfly SO-DIMMs
Perfect for notebookPerfect for notebook Especially thin & light!Especially thin & light!
Single access door to both SO-DIMMsSingle access door to both SO-DIMMs Internet Appliance: 1 or 2 SO-DIMMsInternet Appliance: 1 or 2 SO-DIMMs
CPUNB
SO-DIMM SOCKET
CPUSO-DIMM SOCKET
Motherboard
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Mobile Market RequirementsMobile Market Requirements
Long battery life Long battery life
Small form factorSmall form factor
End-user upgradeEnd-user upgrade
Low power, low heatLow power, low heat
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Power = CVPower = CV22f%f%
Factors:Factors: Capacitance (C)Capacitance (C) Voltage (V)Voltage (V) Frequency (f)Frequency (f) Duty cycle (%)Duty cycle (%) Power statesPower states
Keys to mobileKeys to mobile
design:design:
Reduce C and VReduce C and V Match f to demandMatch f to demand Minimize duty cycleMinimize duty cycle Utilize power statesUtilize power states
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Power: CapacitancePower: Capacitance
DDR capacitance 20% less than SDRDDR capacitance 20% less than SDR Tight circuit board designTight circuit board design Low parasitic socketsLow parasitic sockets
CapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
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Power: DDR vs SDRPower: DDR vs SDRCapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
0
0.5
1
1.5
2
Relative Watts
PC100
(3.3V)
1.2X
PC266
(2.5V)
1.0X
PC133
(3.3V)
2.0X
Lower Voltage means
Lower Power
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Power: DDR vs SDRPower: DDR vs SDRCapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
0
0.2
0.4
0.6
0.8
1
Relative MB/s per Watt
PC100
.31X
PC266
1.0X
PC133
.25X
Double the Bandwidth yet Lower Power
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Power: FrequencyPower: Frequency
Memory speed to match task demandMemory speed to match task demand Adjust memory clock for lowest powerAdjust memory clock for lowest power
Stream back to back operations on open Stream back to back operations on open bank, then closebank, then close DDR burst efficiency really shinesDDR burst efficiency really shines
CapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
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Power: Duty CyclePower: Duty Cycle
Caches minimize memory demandsCaches minimize memory demands DDR cuts burst time in halfDDR cuts burst time in half
Get back into low power state soonerGet back into low power state sooner
CapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
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Long Battery LifeLong Battery Life
Lowest power to perform a taskLowest power to perform a task Desktop performance expectedDesktop performance expected
Battery extending technologies:Battery extending technologies: SpeedStepSpeedStepTMTM
LongRunLongRunTMTM
SpeedStep and LongRun are trademarks of Intel Corporationand Transmeta Corporation, respectively
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Introducing LongRunIntroducing LongRunTMTM
CapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
The number 11 is a trademark of Spinal Tap
LongRunSpeedStep
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LongRunLongRunTMTM Technology Technology
Smart reprogramming of memory Smart reprogramming of memory frequency based on demandfrequency based on demand CPU monitors trends in CPU demandCPU monitors trends in CPU demand Automatically adjust CPU voltage,Automatically adjust CPU voltage,
CPU & memory frequency as neededCPU & memory frequency as needed Utilize all memory power statesUtilize all memory power states
Lowest power state possibleLowest power state possible Close banks between burstsClose banks between bursts
CapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
LongRun is a trademark of Transmeta Corporation
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LongRunLongRunTMTM Advantage AdvantageCapacitanceCapacitance
VoltageVoltage
FrequencyFrequency
Duty cycleDuty cycle
Power statesPower states
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Mobile Market RequirementsMobile Market Requirements
Long battery lifeLong battery life
Low power, low heatLow power, low heat
Small form factorSmall form factor
End-user upgradeEnd-user upgrade
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End User UpgradeEnd User Upgrade
DDR SO-DIMM StatusDDR SO-DIMM Status 63.6 x 31.75mm63.6 x 31.75mm 200 pins on .60mm centers, staggered200 pins on .60mm centers, staggered x64 and x72 (ECC) supportedx64 and x72 (ECC) supported JEDEC specification votes being countedJEDEC specification votes being counted
Multiple mobile designs in progressMultiple mobile designs in progress Samples in test now, production 1Q01Samples in test now, production 1Q01 Also great for small (Flex ATX) desktopAlso great for small (Flex ATX) desktop
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ConclusionsConclusions
Memory of choice for the futureMemory of choice for the future Enables mobile computingEnables mobile computing
Low power yields long battery lifeLow power yields long battery life Small form factor end-user upgradesSmall form factor end-user upgrades
Smart power management schemesSmart power management schemes
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SummarySummary
DDR is here todayDDR is here today Double the bandwidth at lower powerDouble the bandwidth at lower power Evolutionary design change over SDREvolutionary design change over SDR Applies to all market segmentsApplies to all market segments
Industry StandardsIndustry Standards Detailed complete data sheet & modelsDetailed complete data sheet & models Module designs on the webModule designs on the web Visit http://www.ami2.orgVisit http://www.ami2.org
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Thank YouThank You