22-03-2014, 04:18 PM
Intelligent RAM
[attachment=60440]
Introduction and Why there is a Problem
The division of the semiconductor industry into microprocessor and memory camps provides many advantages.
First and foremost, a fabrication line can be tailored to the needs of the device.
Microprocessor fab lines offer fast transistors to make fast logic and many
metal layers to accelerate communication and simplify power distribution, while DRAM fabs offer many polysilicon layers to achieve both small DRAM cells and low leakage current to reduce the DRAM refresh rate.
Advantages
Higher bandwidth and lower latency
Less distance (no bus) and less complexity
Less energy consumption
Less heat, better performance
Costs efficient
Save board space
Disadvantages
Consequences on cost/bit and refresh rate
Manufacturing challenges
Reduce interchangeability
ILP trade-off
Conclusion
VIRAM / DIVA not real successes
but implications in embedded systems
Intel : Through Silicon Vias, personal technology to connect DRAM and processor
First step to IRAM ?
IRAM potential advantage (1)
Higher bandwidth
Gbit DRAM, 3~4 metal layers
Won’t limit performance by bandwidth
Lower latency (<30ns ~ L2)
Wire length the shorter the better
Fewer bits per block the better
More design choices frees designer
Two type of application will be benefit
Predictable memory accesses: (matrix)
50-100-fold increase in IRAM bandwidth
Unpredictable memory accesses, large footprints: (database)
5-10 fold decrease in IRAM latency
IRAM--Summary
IRAM: Merging a microprocessor and DRAM on the same chip
Performance:
reduce latency by 5~10
Increase bandwidth by 50~100
Energy efficiency
Save at 2~4
Cost
Remove off-chip memory and reduce board area
IRAM is limited by amount of memory on Chip
Potential of network computer
Change the nature of semiconductor industry
[attachment=60440]
Introduction and Why there is a Problem
The division of the semiconductor industry into microprocessor and memory camps provides many advantages.
First and foremost, a fabrication line can be tailored to the needs of the device.
Microprocessor fab lines offer fast transistors to make fast logic and many
metal layers to accelerate communication and simplify power distribution, while DRAM fabs offer many polysilicon layers to achieve both small DRAM cells and low leakage current to reduce the DRAM refresh rate.
Advantages
Higher bandwidth and lower latency
Less distance (no bus) and less complexity
Less energy consumption
Less heat, better performance
Costs efficient
Save board space
Disadvantages
Consequences on cost/bit and refresh rate
Manufacturing challenges
Reduce interchangeability
ILP trade-off
Conclusion
VIRAM / DIVA not real successes
but implications in embedded systems
Intel : Through Silicon Vias, personal technology to connect DRAM and processor
First step to IRAM ?
IRAM potential advantage (1)
Higher bandwidth
Gbit DRAM, 3~4 metal layers
Won’t limit performance by bandwidth
Lower latency (<30ns ~ L2)
Wire length the shorter the better
Fewer bits per block the better
More design choices frees designer
Two type of application will be benefit
Predictable memory accesses: (matrix)
50-100-fold increase in IRAM bandwidth
Unpredictable memory accesses, large footprints: (database)
5-10 fold decrease in IRAM latency
IRAM--Summary
IRAM: Merging a microprocessor and DRAM on the same chip
Performance:
reduce latency by 5~10
Increase bandwidth by 50~100
Energy efficiency
Save at 2~4
Cost
Remove off-chip memory and reduce board area
IRAM is limited by amount of memory on Chip
Potential of network computer
Change the nature of semiconductor industry