Note that Excel 2007 is able to use multiple threads to parallelize calculations on the workstation. Previous versions were not. When you hit “recalculate”, Excel will identify independent areas in your spreadsheet and allocate computations in those to separate threads. There are as many calculation threads as cores in your machine. So, before thinking of a cluster, think of a better workstation. For more details, see:
Excel Services (http://msdn2.microsoft.com/en-us/library/ms582023.aspx), a function of Office Sharepoint Server Enterprise, is also multi-threaded, but it uses threads differently from Excel 2007. It does not divide a single spreadsheet across threads. Instead, it uses multiple threads to run several requests (e.g. from different users) against the same spreadsheet at the same time. Similarly, if one user or application opens several spreadsheets, each of them will be handled by a different thread on the server. Hence, Excel Services by itself may not make your calculation any faster. It is mostly intended as a governance solution.
If the power of a multi-core workstation is not sufficient, we can envisage two scenarios:
There are advantages and disadvantages in each case:
The idea of offloading Excel computations is not new; several players are well established in the financial market with such a solution:
-Platform Symphony (www.platform.com) with its Excel adapter (APIs and libraries) has been on the market for a few years and is well accepted, especially in the US market.
-Datasynapse (www.datasynapse.com) has a similar offering for its grid software. It seems to be prevalent in European markets.
-There are also a few research efforts. The articles are worth reading, as they explain how offloading from Excel to grids or clusters can be achieved: http://www.gridbus.org/papers/ExcelGrid.pdf, http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=1324012&isnumber=29307.
-You can download some sample integration code and set up a demonstration environment with Excel, Excel Services and Compute Cluster. Instructions and material have been posted on:
-Read a detailed explanation of how the sample works and a step-by-step installation guide on http://msdn2.microsoft.com/en-gb/library/bb462928.aspx