Реферат на тему CrayA Essay Research Paper A Cray SuperComputer
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Cray(A) Essay, Research Paper
A Cray SuperComputer Comes to the University of Toronto The Cray X-MP/22 manufactured by Cray Research Incorporated(CRI) of Minneapolis, Minnesota was delivered and installed at theU of Toronto this September. The Cray is a well respected computer- mainly for its extremely fast rate of mathematical floating-pointcalculation. As the university states in its July/August computermagazine “ComputerNews”, the Cray’s “level of performance shouldenable researchers with large computational requirements at theuniversity of Toronto and other Ontario universities to competeeffectively against the best in the world in their respectivefields.” The Cray X-MP/22 has two Central Processing Units (CPUs) – thefirst ‘2′ in the ‘22′. The Cray operates at a clock rate of 105 MHz(the regular, run-of-the-mill IBMPC has a clock rate of 4.77 MHz).By quick calculations, you would be led to believe the Cray is onlyabout 20 times faster that the PC. Obviously, this is not the case.The Cray handles data considerably differently than the PC. TheCray’s circuits permit an array of data (known as a ‘vector’) tobe processes as a SINGLE entity. So, where the IBMPC may requireseveral clock cycles to multiply two numbers, the Cray performseverything in one clock cycle. This power is measured in Millionsof Floating Point Operations Per Second (MFLOPS) – which is to saythe rate at which floating-point operations can be performed. TheCray MFLOPS vary as it does many activities, but a rate of up to210 MFLOPS (per CPU) can be achieved. The second ‘2′ in the X-MP/22 title refers to the two million64-bit words (16Mb) of shared central memory. This can be expandedto four million words in the future if the need arises. But itdoesn’t stop there! The Cray can pipe information back and forthbetween the CPU memory and the Input/Output Subsystem (IOS). TheIOS then takes it upon itself the store the information in any ofthe four storage devices: i) one of the four 1200 Mb disk drives(at a rate of 5.9Mb every second), ii) one of two standard 200ips
6250bpi tape drives, iii) a Solid State Storage Device (SSD) (whichis much like a 128Mb RAM Disk!), or iv) through to a front-endcomputer (the U of T uses both the IBM4381 and a DEC VAX). Thesecomputers would be programmed (usually in FORTRAN) and theinformation passed onto the Cray. The results would then betransfered back to the front end computers. The 4 year old Cray was bought used from the California NASAresearch centre where it was used in aerodynamic calculations. Thismeans less cost to buy it and the assurance that it has been ‘burned in’.In case you wanted one for yourself, the U of T was able to purchasethe Cray for the low-low price of $12 million. Over the next fiveyears, the University predicts the total cost will probably be $25million when maintenance, staff and other costs are taken intoconsideration. To help out, the Ontario Government put in $10 million.By doing this, all other Ontario University researchers are assured ofaccess at a reduced cost. By the way, to buy time on the system, it’llcost you $2000 per hour. But Ontario researchers only have to pay 7% ofthat – $140 per hour. Their first commercial customer is OMNIBUSGraphics of Toronto who plan to use the Cray in the graphic videos.If you saw the movie ‘The Last Starfighter’, you will have alreadyexperienced the graphic capabilites of the Cray (remember the some ofthe space scenes!). The Cray did all of the calculations required forthose scenes and let another graphics computer to do the menial taskof drawing the lines and filling with the calculated colour. There is so much to talk about when the word ‘Cray’ pops to mind!If you are seriously interested in this amazing computer and/or you areinterested in purchasing time on the system, please contact thepeople below:The Centre for Large Scale Computation at the U of TLlyod Parker, Director978-8255Facilities ManagerDr. Edmund West978-4085Supercomputer User’s Group (for University Researchers, etc)Professor Philip Kromberg978-4971