Sorry, Mr. pizza ...
Posted Apr 15, 2008 1:17 UTC (Tue) by JoeBuck
In reply to: My kid hates Linux (ZDNet)
Parent article: My kid hates Linux (ZDNet)
... but I wasn't speaking theoretically. I work in electronic design automation.
The doubled-memory effect really does overwhelm the effect of having more registers, 64-bit math and a better machine architecture in many real cases, particularly when the program's working set is in the gigabytes. The time to move that data through the CPU overwhelms all other considerations. The 64-bit executable wins when the working set exceeds the 32-bit address space, of course, but in the range where the 32-bit program requires 1-2 Gbytes and the 64-bit program needs nearly double that.
For this reason, many EDA applications are available in both 32-bit and 64-bit versions, and the recommendation to the customer is to use the 32-bit version even on the 64-bit machine except where the problem is too large.
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