S.C. a CDC founder? fantastic!
205/LSI after the Cray-1? check.
Ok, continuing after a "real work"* break.
What made the 205 get singled out for so
long as an a**kicker? True multiprocessing?
Did it beat the Cray-1?
CYBER 205
Overview of Platform
Vector Architecture.
Compute Hardware
Architecture: ECL/LSI logic (168 gates/chip) Sequential and parallel
processing on single bits, 8-bit bytes and 32- or 64-bit floating-point
operands 20-nsec cycle time Scalar Unit Segmented functional units 64-word
instruction stack 256 word high-speed register file Vector Unit 1, 2, or 4
segmented vector pipelines memory-to-memory data streaming maximum vector
length of 65,536 words gather/scatter instructions up to 800 million 32-bit
floating-point operations/second
Interconnect / Communications System
Memory System
Memory
MOS semiconductor memory
Memory size: 1, 2, 4, 8 or 16 million 64-bit words
Virtual memory accessing mechanism with multiple, concurrently
usable page sizes
SECDED on each 32-bit half word
48-bit address (address space of 4 trillion words per user)
80 nsec memory bank cycle time
Memory bandwidth: 25.6 or 51.2 Gigabits/second
Benchmarks / Compute and data transfer performance
Performance:
Linked triad performance on long vectors approaches asymptotic
speed of machine.
Performance can be severely degraded at short vector lengths
(that is, the typical $n _ {1/2}$ is around 100), and if
vector is not held contiguously. For this reason most
tuned software employs long, contiguously held vectors.
Operating System Software and Environment
Software:
Virtual operating system
Batch and interactive access
FORTRAN compiler
ANSI 77 with vector extensions
32-bit half-precision data type
Special calls to machine instructions
Automatic vectorization
Scalar optimization utilizing large register file
Utilities
Interactive symbolic debugger
Source code maintenance
Object code maintenance
Networkability/ I/O System / Integrability / Reliability / Scalability
I/O
Eight I/O ports, 32-bits in width, expandable to 16
200 Mbits/second for each port
Maximum I/O port bandwidth of 3200 Mbits/sec
Miscellaneous
Cooling: freon
Dimensions: floor area (four pipe model) 23 ft x 19 ft
footprint (with I/O system) 105 sq ft
Notable Applications / Customers / Market Sectors
N/A
Overall Comments
N/A
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