Questions tagged [cray]
For questions relating to the supercomputers made by Cray Research and its successors.
12 questions
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3
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Cray quote about supercomputers... a megaflop needs a megaword or similar?
I'm trying to find a quote that I'm 90% certain was attributed to Cray. It was to the effect that a computer that processes at a rate of one megaflop also needed a megaword of memory and [something ...
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5
votes
1
answer
293
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Where to find the Cray arithmetic library?
Given a Cray simulator
and a pre-installed UniCOS HD image, attempting to compile Steven Pemberton's ENQUIRE (literally, the second thing to try after "Hello, Cray") fails with
CC-1153 cc: ...
- 20.7k
4
votes
0
answers
256
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First machine with dedicated scatter/gather?
I know the Cray-1 had scatter/gather addressing, but I am curious if anyone knows what the first machine with this feature might be?
I suspect it is one of the vector machines from this era, perhaps ...
- 21k
21
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5
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8k
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The Cray 1 used 115 kW of power. How was that much grid power physically delivered to the unit?
We are talking power plant levels of current to power the the thing. Did it just have 2 inch lugs?
- 327
3
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2
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What was the first vector supercomputer?
I am trying to understand the trade-offs between scalar and vector machines, the threshold of complexity/transistor count/performance at which vector machines started to make sense.
As data points, ...
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2
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2
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547
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How did the NSA use vector supercomputers?
In the 80s, the NSA was a major customer of supercomputers. https://www.nsa.gov/Portals/70/documents/news-features/declassified-documents/cryptologic-quarterly/NSA_and_the_Supercomputer.pdf discusses ...
- 63.8k
3
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1
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Cray-1 functional units
The Cray-1 has 12 segments arranged in a 270 degree arc. It also has 12 functional units, so is there one functional unit per segment?
There were 1,662 modules in 113 varieties, but what is a module? ...
- 1,869
11
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4
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Shape of Cray-1
One way the fast speed of the Cray-1's CPU was achieved was by keeping the wire lengths short. How did the C-shape of the Cray-1 help here? Were the speed-dependent portions on the inside edge where ...
- 1,869
1
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1
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How good a Cray could be as a video game console? [closed]
The stats are: https://en.wikipedia.org/wiki/Cray-1
Memory: 8.39 Megabytes (up to 1 048 576 words)
CPU: 64-bit processor @ 80 MHz
The 24-bit address arithmetic was performed in an add unit and a ...
- 409
19
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4
answers
4k
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Why did the Cray-1 have 8 parity bits per word?
According to https://en.wikipedia.org/wiki/Cray-1
The Cray-1 was built as a 64-bit system, a departure from the 7600/6600, which were 60-bit machines (a change was also planned for the 8600). ...
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20
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Did Cray computers use virtual memory?
I found a mention on page 777 of the Second Edition of the book "Computer Systems: a programmer's perspective" [Bryant - O'Hallaron] stating that Cray supercomputers still do not use virtual memory (...
- 549
38
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6
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10k
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Why does the Cray 2 use 400 Hz power, and why generate that from motors?
This Cray sales brochure details on page 4 that the Cray-2 uses 400 Hz power, and generates this from motors.
400 Hz power from motor generators
I'm not sure that in 1986, the state of the art ...
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