Is accessing data in the heap faster than from the stack?

Question

I know this sounds like a general question and I\'ve seen many similar questions (both here and on the web) but none of them are really like my dilemma.

Say I have t

Answer 1

There is blog post available on this topic stack-allocation-vs-heap-allocation-performance-benchmark Which shows the allocation strategies benchmark. Test is written in C and performs compare between pure allocation attempts, and allocation with memory init. At different total data sizes, number of loops are performed and time is measured. Each allocation consists of 10 different alloc/init/free blocks with different sizes (total size shown in charts).

Test are run on Intel(R) Core(TM) i7-6600U CPU, Linux 64 bit, 4.15.0-50-generic, Spectre and Meltdown patches disabled.

With out init:

With init:

In the result we see that there is significant difference in pure allocations with out data init. The stack is faster than heap, but take a note that loop count is ultra high.

When allocated data is being processed, the gap between stack & heap performance seems to reduce. At 1M malloc/init/free (or stack alloc) loops with 10 allocation attempts at each loop, stack is only 8% ahead of heap in terms of total time.