Finding the cache block size

Question

How do I find the cache block size in Ubuntu, programmatically (with C++) or otherwise?

@ChadLaGuardia I would say it is not a duplicate because that question is limited in scope to only C++. Here OP is open to methods outside of the specific language, such as a cli command. — The Unknown Dev, Apr 10 '16 at 21:03

score 12 · Accepted Answer · answered Mar 23 '11 at 14:13

12

You can find it in /proc/cpuinfo; cache size for the total size, and cache_alignment for the block size.

answered Mar 23 '11 at 14:13

Mike Seymour

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score 0 · Answer 2 · answered Mar 23 '11 at 11:21

One way is to fill an std::vector or just a plain array with random values, and do something simple, e.g. square each element in a loop. Then measure the execution time as a function of the vector length. You'll very clearly see a jump in the exec time once your vector does not fit into the cache.

Finding the cache block size

2 Answers2