Brendan Gregg

FEBRUARY 28, 2023

My personal opinion is that I don't see a widespread need for more capacity given horizontal scaling and servers that can already exceed 1 Tbyte of DRAM; bandwidth is also helpful, but I'd be concerned about the increased latency for adding a hop to more memory. The call for participation ends on March 2nd 23:59 SGT!

Performance 110

Performance Latency Cache Virtualization 110

Sutter's Mill

FEBRUARY 13, 2017

Tue-Thu Apr 25-27: High-Performance and Low-Latency C++ (Stockholm). On April 25-27, I’ll be in Stockholm (Kista) giving a three-day seminar on “High-Performance and Low-Latency C++.”

Latency 51

Latency C++ Hardware Performance 51

Brendan Gregg

FEBRUARY 28, 2023

My personal opinion is that I don't see a widespread need for more capacity given horizontal scaling and servers that can already exceed 1 Tbyte of DRAM; bandwidth is also helpful, but I'd be concerned about the increased latency for adding a hop to more memory. It was a great privilege. That's about 24 hours from now!

Performance 52

Performance Latency Cache Virtualization 52

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. Was there some other program consuming CPU, like a misbehaving Ubuntu service that wasn't in CentOS? As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI.

Speed 126

Speed Java AWS Virtualization 126

Alex Russell

JANUARY 30, 2024

HTML, CSS, images, and fonts can all be parsed and run at near wire speeds on low-end hardware, but JavaScript is at least three times more expensive, byte-for-byte. If you or your company are able to generate a credible worldwide latency estimate in the higher percentiles for next year's update, please get in touch.

Performance 90

Performance Network Mobile Speed 90

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. Was there some other program consuming CPU, like a misbehaving Ubuntu service that wasn't in CentOS? As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI.

Speed 40

Speed Java AWS Virtualization 40

John McCalpin

JANUARY 22, 2018

Introduction: In December 2017, my colleague Damon McDougall (now at AMD) asked for help in porting the fused multiply-add example code from a Colfax report ( [link] ) to the Xeon Phi x200 (Knights Landing) processors here at TACC. A peculiar throughput limitation on Intel’s Xeon Phi x200 (Knights Landing). cmpl $1000000000, %eax.

Latency 40

Latency Hardware Code Testing 40