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MEMORY TECHNOLOGY FOR SMALL FORM FACTOR SYSTEMS. Bill Gervasi Chairman, JEDEC Memory Parametrics. Market Changes. Desktop PC getting smaller and smaller Flex/ATX form factor Tiny sealed box legacy free PCs Server market shifts to 1U form factor Packing more CPUs into a smaller frame
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MEMORY TECHNOLOGY FOR SMALL FORM FACTOR SYSTEMS Bill Gervasi Chairman, JEDEC Memory Parametrics
Market Changes • Desktop PC getting smaller and smaller • Flex/ATX form factor • Tiny sealed box legacy free PCs • Server market shifts to 1U form factor • Packing more CPUs into a smaller frame • Heat dissipation a top concern • Performance ramping higher and higher • System (fan) noise concerns
It’s Time for a Change • PC demand plateau at 128-256 MB • DDR SO-DIMM clearly meets this need • 30% of FlexATX PCB is memory sockets & traces • 1U = 86% of server market (by unit) • Trying to fit 6-8 CPUs in one 19” rack • Increasing operating frequency harder to achieve with 5¼“ DIMM
DDR Modules SO-DIMM DIMM NEW! MicroDIMM
SO- and Micro- DIMMs DDR DIMM = 133.3 mm DDR SO-DIMM = 67.6 mm = 50% shorter! DDR MicroDIMM = 45.5 mm = 66% shorter!!!
FlexATX Footprint North Bridge Copper Slots With DIMM: 17k mm2 With SO-DIMM: 7k mm2 Area saved~ 60%
Server Market 1U form factor or blade600 MHz x86 CPU256MB – 1GB RAM (by unit shipment; source = Intel)
1U Thin and 3U Blades 1U Right Angle Socket Vertical Socket 3U
Operating Frequency DIMM 4,8,9,16,18,36 chips x4, x8, x16 devices Unbuffered or Registered SO-DIMM 4,5,8 chips x8, x16 devices Unbuffered Only MicroDIMM 4,8 chips x16 devices Unbuffered Only Which do you think will run the fastest?
SO-DIMM Requirements • Low cost vertical socket needed • Smallest PCB footprint • Enable 4 layer motherboard • Socket concepts in progress • Staggered surface mount • Single routing layer possible! • Right angle socket okay for blade
Discussions Under Way Began negotiations with the major mother board manufacturers – all are open to evaluating the concept Of course, no one will make the move unless WE ALL MOVE TOGETHER
Fire Started • One major embedded application on the hook • Production of 250 Ku/mo beginning 1Q02 • Enough to kick start the program • Task group formed • Conference calls to gather requirements • Socket suppliers debating implementation & cost details
We have an opportunity to establish the DDR SO-DIMM as the highest volume, lowest cost, highest performance memory module in the industry.
What about MicroDIMM? • Notebooks & subnotebooks • PDAs and Web Tablets • High density 1U servers???
High Density 1U CPU CPU Mem Mem CPU CPU Mem Mem Interconnect fabric and I/O CPU CPU Mem Mem CPU CPU Mem Mem
MicroDIMM Requirements • DDR MicroDIMM used in high density 1U • Right angle socket okay… 1x2” footprint • One module per CPU • No vertical socket demand seen… yet…
Dealing w/ heat and noise • Greatest challenge for 1U server is HEAT • Dissipating heat takes FANS • Fans generate MORE HEAT
Fanless Desktop PC? • What doesn’t fit? • MP3 music • 100W per channel amp • Bose surround sound speaker system • PC fans with 75 dB of white noise
Power: DDR vs SDR Lower Voltage meansLower Power PC133 (3.3V) 2.0X PC100 (3.3V) 1.2X DDR266 (2.5V) 1.0X
Power: DDR vs SDR Double the Bandwidth yet Lower Power DDR266 1.0X PC100 .31X PC133 .25X
DDR Reduces Power • Using DDR for main memory helps control system power • Lower power reduces or eliminates need for fans
Bold Projection • Fanless desktop PCs for home and small office will become a significant market demand • DDR will help enable this important market segment
Another Wild Card • Low Power SDR • 1.8V • No DLL • Inventive refresh options • Some focus here, especially for cell phones… will it spread? • Features considered for DDR family, too
Cached DRAM Power Profile Higher Power Page Miss Power Profile … NOP ACT R-PRE R … R NOP Command Activity Page Hit Power Profile Lower Power NOP R R R R NOP Command Activity
Conclusions • Market form factors are changing • New designs require rethinking our past assumptions • DDR SO-DIMM could replace the DIMM for desktop applications • Lower power would allow us to eliminate noisy fans