Questions tagged [cray]
For questions relating to the supercomputers made by Cray Research and its successors.
14 questions
13 votes
1 answer
492 views
Did CRAY's computers have a guard bit?
The paper What Every Computer Scientist Should Know About Floating-Point Arithmetic uses the Cray's systems as an example of computers without a guard bit: Although most modern computers have a guard ...
- 131
6 votes
3 answers
594 views
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 ...
- 22.4k
4 votes
0 answers
265 views
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 ...
- 22.4k
3 votes
2 answers
428 views
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, ...
- 65.3k
3 votes
1 answer
380 views
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? ...
- 1,995
1 vote
1 answer
735 views
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 ...
- 429
20 votes
3 answers
5k views
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