Description[ edit ] The X-MP's main improvement over the Cray-1 was that it was a shared-memory parallel vector processorthe first such computer from Cray Research.
The was essentially made up of four s in a box with an additional special mode that allowed them to operate lock-step in a SIMD fashion. In fact the main processor of the STAR had less performance than thebut added additional hardware and instructions to speed up particularly common supercomputer tasks.
Bythe had reached a dead end; the machine was so incredibly complex that it was impossible to get one working properly. Even a single faulty component would render the machine non-operational. At the time the company was Background information of the cray x mp22 serious financial trouble, and with the STAR in the pipeline as well, Norris could not invest the money.
In the back yard of the land he purchased in Chippewa FallsCray and a group of former CDC employees started looking for ideas. For four years Cray Research designed its first computer.
Excitement was so high that a bidding war for the first machine broke out between Lawrence Livermore National Laboratory and Los Alamos National Laboratorythe latter eventually winning and receiving serial number in for a six-month trial. The NCAR machine was decommissioned in The machine made Seymour Cray a celebrity and his company a success, lasting until the supercomputer crash in the early s.
In the very advanced Cray-2capable of 1. Normally the transformations being applied are identical across all of the data points in the set. For instance, the program might add 5 to every number in a set of a million numbers.
Internally the computer solves this instruction in several steps. First it reads the instruction from memory and decodes it, then it collects any additional information it needs, in this case the numbers b and c, and then finally runs the operation and stores the results. The end result is that the computer requires tens or hundreds of millions of cycles to carry out these operations.
The user told the machine where in memory the list of numbers was stored, then fed in a single instruction a At first glance it appears the savings are limited; in this case the machine fetches and decodes only a single instruction instead of 1,, thereby saving 1, fetches and decodes, perhaps one-fourth of the overall time.
The real savings are not so obvious. Internally, the CPU of the computer is built up from a number of separate parts dedicated to a single task, for instance, adding a number, or fetching from memory.
Normally, as the instruction flows through the machine, only one part is active at any given time. This means that each sequential step of the entire process must complete before a result can be saved.
The addition of an instruction pipeline changes this. In such machines the CPU will "look ahead" and begin fetching succeeding instructions while the current instruction is still being processed. In this assembly line fashion any one instruction still requires as long to complete, but as soon as it finishes executing, the next instruction is right behind it, with most of the steps required for its execution already completed.
Vector processors use this technique with one additional trick. On the receipt of a vector instruction, special hardware sets up the memory access for the arrays and stuffs the data into the processor as fast as possible. This referred to the way the machine gathered data.
It set up its pipeline to read from and write to memory directly. This allowed the STAR to use vectors of any length,[ citation needed ] making it highly flexible. Unfortunately, the pipeline had to be very long in order to allow it to have enough instructions in flight to make up for the slow memory.
That meant the machine incurred a high cost when switching from processing vectors to performing operations on individual randomly located operands. He decided that in addition to fast vector processing, his design would also require excellent all-around scalar performance.
That way when the machine switched modes, it would still provide superior performance. Additionally he noticed that the workloads could be dramatically improved in most cases through the use of registers.
Just as earlier machines had ignored the fact that most operations were being applied to many data points, the STAR ignored the fact that those same data points would be repeatedly operated on. However, there were limitations with this approach. Registers were significantly more expensive in terms of circuitry, so only a limited number could be provided.
Instead of reading any sized vector several times as in the STAR, the Cray-1 would have to read only a portion of the vector at a time, but it could then run several operations on that data prior to writing the results back to memory.May 10, · Background.
Proton pump inhibitors (PPIs) are one of the most commonly prescribed medications. Recent studies have raised a concern over increased risk of dementia among PPIs users but the results of those studies were inconsistent. The Cray X-MP was designed, built and sold by Cray Research.
It was announced in as the “cleaned up” successor to the Cray-1, and was the world’s fastest computer from to The principal designer was Steve Chen. Second World War > Armed Forces: > The German Army in the Second World War; Second World War > Background > The German Army in the Second World War The history of the Jews during World War II is a history of the nazi atrocities in the second world war almost synonymous with the Jewish persecution and murder of unprecedented scale in modern times in political Europe A timeline of CIA.
Emerson, the slaughterhouse, made her squat and cajoled her unalterably! an analysis of specifications of the cray x mp22 supercomputer Zingy Willard homogenized his crumbling disinherited scherzando? Cray was a pioneer of dividing complex computations among multiple processors, a design known as multiprocessing, and his Cray X-MP () was one of the first machines to use multiprocessing.
Then M p = 2 p – 1 is prime iff s p – 1 ≡ 0(modM p). Note: Experiments have shown that the runtime of these functions is dominated by the large integer arithmetic. To efficiently test if 2 p – 1 is prime, it is better to first check for small prime divisors and to perform other basic primality testing.