Performance Matters

Jun 17, 2021
Your CPU May Have Slowed Down on Wednesday
The death of hardware store optimization.
Aug 19, 2020
Ice Lake AVX-512 Downclocking
Examining the extent of AVX related downclocking on Intel's Ice Lake CPU
Jul 6, 2020
A Concurrency Cost Hierarchy
Concurrent operations can be grouped relatively neatly into categories based on their cost
May 26, 2020
AVX-512 Mask Registers, Again
Taking a second look at the newly introduced mask registers, this time with the benefit of a SKX die shot from Fritzchens Fritz.
May 18, 2020
Ice Lake Store Elimination
We look at the zero store optimization as it applies to Intel's newest micro-architecture.
May 13, 2020
Hardware Store Elimination
Probing a previously undocumented zero-related optimization on Intel CPUs.
Feb 5, 2020
Adding Staticman Comments
Adding static comments to a static blog using staticman. Static.
Jan 20, 2020
The Hunt for the Fastest Zero
Unexpected performance deviations depending on how you spell zero.
Jan 17, 2020
Gathering Intel on Intel AVX-512 Transitions
Investigating some details of SIMD related frequency transitions on Intel CPUs.
Dec 5, 2019
A Note on Mask Registers
Some mostly too-low-level-to-care-about hardware details of the mask registers introduced in AVX-512.
Nov 19, 2019
Clang-format Tanks Performance
Can using clang-format make your code slower? Kind of.
Aug 26, 2019
Incrementing Vectors
Incrementing vector<T> for various T may not perform as you'd expect.
Aug 20, 2019
Where Do Interrupts Happen?
Trying to determine exactly where asynchronous interrupts are delivered on Intel CPUs.
Jun 11, 2019
Performance Speed Limits
A laundry list of speed limits that your code can't exceed.
May 22, 2019
Beating Up on Qsort
Building sort functions faster than what the C and C++ standard libraries offer.
Mar 19, 2019
What Has Your Microcode Done for You Lately?
CPU microcode updates can cause silent and dramatic performance changes.
Mar 18, 2019
A Blog Appears!
If there’s one thing the internet needs, it’s another blog. So after messing around with Jekyll and Github Pages for way longer than is reasonable, here we are.