4. Introduction to IRAM
• History
In a 1996–2004 research project in the
Computer Science Division of the University
of California, Berkeley, the Berkeley IRAM
project explored Computer
Architecture enabled by the wide
bandwidth between memory and processor
made possible when both are designed on
the same IC.
• Intelligence stands for
Microprocessor and RAM
stands for memory
• Merges RAM and ProcessorFig. 1 IRAM
5.
6. Inspiration of IRAM
• Why we need IRAM???
problems:
Processor-Memory Performance Gap
“AWKWARDNESS” of high capacity DRAM chips
7. Inspiration of IRAM
• Solution of problems
Provide a more cache memory
Put the processor on SRAM
Put the processor in DRAM
• Why select DRAM ???
DRAM is 20 times denser than SRAM.
Thus, IRAM enables a much larger amount of on-chip memory
than is possible in a conventional architecture.
8. Inspiration of IRAM
Time to be double
demand for processing
power and memory
2 months
Microprocessor 18 months
DRAM 120 months
9.
10. IRAM Architecture
• The Key Technologies behind the IRAM technology are,
1) Vector Processing
2) Embedded DRAM and
3) Serial I/O Vector Processing
1) Vector Processing:
Vector architecture deals with vector processing so represents
only PROCESSOR architecture
Helps to study parallel processing of IRAM
Parallel processing carried out by virtual processing of IRAM
processor
11. IRAM Architecture
Vector Architecture of IRAM
• Advantages of Vector
Processing:
high performance
on demand for
multimedia
processing
low power for issue
of control logic
Because of less
Complexity in
design it’s cheap
and very easy in
implementation
12. IRAM Architecture
2) Embedded DRAM :
• Embedded technology means a chip is embedded into a device
for control and well execution of operations of that particular
device.
• During the fabrication the memory chip is embedded into the
microprocessor to produce IRAM. Thus IRAM becomes a single
chip into which both memory and processor are integrated for
high quality performance due to their coexistence.
• ADVANTAGES:
High Bandwidth
Low latency
Memory Access frequency low
Memory Flexibility
13. IRAM Architecture
3) Serial I/O Vector Processing:
• Due to POOR Processing of earlier technology, Serial I/O Vector
processing is used.
• Much more efficient and cost effective
• Enhances performance of IRAM by offering smooth and faster
path for data transfer without hindering memory and processor
performances
• ADVANTAGES:
Offers very high band width in terms of GB/sec which is
greater than both
Pin count is less
Power Consumption is less than Parallel I/O
14.
15. Advantages of IRAM
Lower Latency
Energy Efficiency
Higher Bandwidth Decrease time
delay due to
not multiplexing
addresses and
less BUS
length. Also
doesn’t have
parallel DRAMs
and less no. of
pins.
Energy per memory access
= AEL1 + MRL1 x
AEL2 + MRL2 x AEoff-
chip
where AE = access energy
and MR = miss rate
Doesn’t need of L2
cache. So
energy
Efficiency is
HIGH.
RAM and
Processor are
on single chip
so less BUS
length and
due to that
Higher data
transfer.
16. Advantages of IRAM
Board Area
Memory Flexibility
Cost of Production
Fabrication of RAM
and Processor
is done in a
single
fabrication line.
Integrates several
chips into ‘One
Chip’. So,
SMALL board
area requires.
Over conventional
designs is the
ability to adjust
both the size
and width of the
on-chip DRAM
17.
18. Disadvantages of IRAM
Completely new
Architecture
For the
acceptance of
this new
technology we
have to discard
our current
products and
technologies
High Cost of
Testing
Adding a
processor
would
significantly
increase the
test time
Non Upgradeability
of Memory
DRAM chips are
embedded in the
IRAM chip,
So,we will not be
able to upgrade
the memory
further
Overheating
even though the
heat produced is
Less compared to
Current
processors
it may overheat
due to the small
area
19. Applications of IRAM
• Scientific computing
• Lossy Compression (JPEG, MPEG video and audio)
• Cryptography (RSA, DES/IDEA, SHA/MD5)
• Multimedia Processing (compress., graphics, audio synth,
image proc.)
• Speech and handwriting recognition
• Operating systems/Networking
• Databases (hash/join, data mining, image/video serving)
• Language run-time support (stdlib, garbage collection)
20. Applications of IRAM
• Nowadays, GIGABYTE is
manufacturing IRAM commercially
Package Content
• One GIGABTE i-RAM
• One SATA 1.5Gb/s cable
• One i-RAM CD Driver
• One i-RAM Manual
21. References
• IRAM - Chips that remember and compute, IEEE International Solid State
Circuits Conference
• Vector IRAM - ISA and Micro-architecture, Computer Science Division,
University of California, Berkeley
• Vector IRAM - A Media-oriented Vector Processor with Embedded DRAM,
Computer Science Division, University of California, Berkeley
• A Media-enhanced vector architecture for embedded memory systems,
Computer Science Division, University of California, Berkeley
• Memory-Intensive Benchmarks: IRAM vs. Cache-Based Machines,
Computer Science Division, University of California, Berkeley
• IRAM - Overcoming the I/O Bus Bottleneck, Denver, CO, USA
• The energy efficiency of IRAM architectures, 24th Annual International
Symposium on Computer Architecture
• http://iram.cs.berkeley.edu/
• http://wikipedia.org