We investigate the secret connection between class layout and software performance. And of course, how to make your software faster.
All posts tagged data cache
Horrible Code, Clean Performance
A short tale of how horrible code yields clean performance.
Frugal Programming: Saving Memory Subsystem Bandwidth
We investigate techniques of frugal programming: how to program so you don’t waste the limited memory resources in your computer system.
The memory subsystem from the viewpoint of software: how memory subsystem affects software performance 2/3
We continue the investigation from the previous post, trying to measure how the memory subsystem affects software performance. We write small programs (kernels) to quantify the effects of cache line, memory latency, TLB cache, cache conflicts, vectorization and branch prediction.
Memory consumption, dataset size and performance: how does it all relate?
We investigate how memory consumption, dataset size and software performance correlate…
When vectorization hits the memory wall: investigating the AVX2 memory gather instruction
For all the engineers who like to tinker with software performance, vectorization is the holy grail: if it vectorizes, this means that it runs faster. Unfortunately, many times this is not the case, and the results of forcing vectorization by any means can mean lower performance. This happens when vectorization hits the memory wall: although…
Why do programs get slower with time?
We investigate why software gets slower as new features are added or data set grows and what can you do about it.
The quest for the fastest linked list
Linked lists are celebrity data structures of software development. They are celebrities because every engineer has had something to do with them in one part of their career. They are used in many places: from low-level memory management in operating systems up to data wrangling and data filtering in machine learning. They promise a lot:…
Memory Access Pattern and Performance: the Example of Matrix Multiplication
We use matrix multiplication example to investigate loop interchange and loop tiling as techniques to speed up your program that works with matrices.
The true price of virtual functions in C++
We talk about virtual functions, and how the performance of software with virtual functions depends on many factors: the cost of additional instructions, cache misses, branch prediction misses, instruction cache misses and compiler optimizations.