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. Ford, et al., “TCP

Performance 110

Performance Latency Cache Virtualization 110

Brendan Gregg

JULY 4, 2021

AWS Graviton2); for memory with the arrival of DDR5 and High Bandwidth Memory (HBM) on-processor; for storage including new uses for 3D Xpoint as a 3D NAND accelerator; for networking with the rise of QUIC and eXpress Data Path (XDP); and so on. Ford, et al., “TCP

Performance 140

Performance Latency Hardware Storage 140

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. Ford, et al., “TCP

Performance 52

Performance Latency Cache Virtualization 52

Brendan Gregg

JULY 4, 2021

AWS Graviton2); for memory with the arrival of DDR5 and High Bandwidth Memory (HBM) on-processor; for storage including new uses for 3D Xpoint as a 3D NAND accelerator; for networking with the rise of QUIC and eXpress Data Path (XDP); and so on. Ford, et al., “TCP

Performance 52

Performance Latency Hardware Storage 52

Alex Russell

APRIL 29, 2021

Real-time network protocols for enabling videoconferencing, desktop sharing, and game streaming applications. Delayed three years ( Chrome 40, November 2014 vs. Safari 11.1, Modern, asynchronous network APIs that dramatically improve performance in some situations. Delayed five years. Gamepad API. Delayed three years [8].

Media 145

Media Games Education Engineering 145

Brendan Gregg

SEPTEMBER 5, 2017

Here's some output from my zfsdist tool, in bcc/BPF, which measures ZFS latency as a histogram on Linux: # zfsdist. Tracing ZFS operation latency. At my employer we sometimes use SR-IOV for direct network interface access, and NVMe for direct disk access. Hit Ctrl-C to end. ^C x series.

Virtualization 76

Virtualization AWS Engineering Hardware 76

Brendan Gregg

AUGUST 8, 2017

And here's an excerpt from [Linux] today (include/linux/sched/loadavg.h): #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */ #define EXP_5 2014 /* 1/exp(5sec/5min) */ #define EXP_15 2037 /* 1/exp(5sec/15min) */. 90491 N|rnberg (Germany) Consulting+Networking+Programming+etc'ing 42. Network I/O? termc$ uptime.

Latency 111

Latency Metrics C++ Systems 111