Matlab code giving wrong answers on system with i9 processor

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Mike Collins 2020-1-22

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评论： Star Strider 2020-2-6

Hello,

We have many different types of computers with Matlab installed on them. One computer in particular seems to be doing calculations wrong.

This system is an HP Zbook with an intel i9 9880H processor in it. The system has had Matlab R2017b installed on it which has been removed and reinstalled multiple times with the same exact results.

Have you seen anything like this or have any idea what may be causing it?

Thank you,

Mike

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James Tursa 2020-1-22

Can you isolate the calculation that gives different results and post it?

Mike Collins 2020-1-22

Yes, they are all on either i7 or newer Xeon processors all made by Dell, some Desktops, some laptops. This new HP Zbook with an i9 is our first test with an Intel i9 and our first instance of this issue.

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采纳的回答

Mike Collins 2020-2-5

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编辑：Mike Collins 2020-2-5

The issue was found to be related to the hardware. A technician had taken the hdd out of the HP Zbook and installed it into a different computer (Dell Precision). The issue was then resolved. Something with the hardware, either the processor or the board was handling floating points differently. Thank you all for your input!

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Walter Roberson 2020-2-6

One question I would have is whether the "errors" occur on all array sizes, or only on "small" arrays, or only on "larger" arrays. I ask because for "larger" arrays, MATLAB tends to call BLAS or LAPACK or MKL functions to do highly optimized calculations, but for "smaller" arrays, MATLAB executes the operations itself.