Whitepapers

E L I T E C H A N N E L PA R T N E R simulation@rand.com | RandSIM.com | 888.483.0674 Understanding and Predicting the ROI of High-Performance Computing Central Concepts – The Analogy In the analogy below, the students are computer cores, the exam is the simulation problem, and the interconnect is the language or method by which they communicate their answers to the next person. Let's say 12 students need to solve 60 questions. 1. Through the Serial method, one student will answer all 60 questions. Assuming that students solve each problem in 4 seconds, which is 15 problems a minute, all 60 questions will be solved in approximately 4 minutes. 2. Through the Parallel method, each of the 12 students will answer 6 questions. Because the difficulty of each question—and the capabilities of each student—varies, we are now dependent on the solve time of the slowest student. Let's say that is now 6 seconds per problem instead of the averaged 4 seconds. We define this as "load balancing", or the distribution of workload appropriately in order to resolve simulta- neously. Because we didn't account for that, we took a hit to efficiency. The slowest solve speed was 6 seconds per problem, which equates to 10 problems a minute per student, and 120 problems can be solved per minute. The parallel method drastically increased solve speed from 15 problems a minute to 120 problems per minute, but it wasn't linearly matched with the increased number of minds allocated to the problem (1 versus 12). This equates to a scaling efficiency of 63%. This analogy demonstrates how utilizing more cores for your simulation model via HPC will impact your solve speeds and provide quicker results. Introduce Communication Speed Impacts Other than the first question, let's say that each question requires the answer to the previous question from the person to their left. For example: Question 1: 5*3 = A n n is the active student, n-1 is the student to their left Question 2: 4*A n-1 = B n Solution requires answer from previous question completed by student on their left Question 3 2*B n-1 = C n Now, individuals need to solve the problems efficiently, and they need to communicate the results to the appropriate person in an efficient manner.

• Cover