John McCalpin

FEBRUARY 17, 2025

“Latency” is the duration from the execution of a load instruction (to an address that misses in all the caches), and the completion of that load instruction when the data is returned from memory. . The example below is for a 2005-era processor with 60 ns memory latency and 6.4

Latency 40

Latency Hardware Cache Systems 40

The Morning Paper

OCTOBER 4, 2020

We are standing on the eve of the 5G era… 5G, as a monumental shift in cellular communication technology, holds tremendous potential for spurring innovations across many vertical industries, with its promised multi-Gbps speed, sub-10 ms low latency, and massive connectivity. Throughput and latency. energy consumption).

Energy 130

Energy Latency Performance Network 130

Scalegrid

DECEMBER 21, 2023

Identifying key Redis® metrics such as latency, CPU usage, and memory metrics is crucial for effective Redis monitoring. To monitor Redis® instances effectively, collect Redis metrics focusing on cache hit ratio, memory allocated, and latency threshold.

Strategy 130

Strategy Monitoring Latency DevOps 130

All Things Distributed

JANUARY 18, 2012

Amazon DynamoDB offers low, predictable latencies at any scale. This is not just predictability of median performance and latency, but also at the end of the distribution (the 99.9th percentile), so we could provide acceptable performance for virtually every customer. s read latency, particularly as dataset sizes grow.

Scalability 162

Scalability Database Ecommerce Latency 162

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 48

Latency C++ Hardware Performance 48

All Things Distributed

JULY 14, 2015

Streams provide you with the underlying infrastructure to create new applications, such as continuously updated free-text search indexes, caches, or other creative extensions requiring up-to-date table changes. DynamoDB Streams enables your application to get real-time notifications of your tables’ item-level changes.

Database 158

Database Lambda AWS IoT 158

Percona

JUNE 22, 2023

This includes metrics such as query execution time, the number of queries executed per second, and the utilization of query cache and adaptive hash index. query cache: Disable (query_cache_size: 0, query_cache_type:OFF) innodb_adaptive_hash_index: Check adaptive hash index usage to determine its efficiency.

Performance 136

Performance Monitoring Traffic Database 136

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 103

Performance Latency Cache Virtualization 103

Percona

MAY 2, 2023

ChatGPT: The InnoDB buffer pool is used by MySQL to cache frequently accessed data in memory. If we expand the cache concept more, the buffer pool could be even less if the working set (hot data) is smaller. The answer does not consider the queue or latency of the sample, which could indicate a disk with issues.

Social Media 145

Social Media Database Servers Cache 145

John McCalpin

DECEMBER 6, 2016

The Xeon Phi x200 (Knights Landing) has a lot of modes of operation (selected at boot time), and the latency and bandwidth characteristics are slightly different for each mode. In “Cache” mode, MCDRAM memory is used as an L3 cache for the main DDR4 memory. numactl).

Latency 40

Latency Cache Testing Systems 40

John McCalpin

APRIL 25, 2023

For most high-end processors these values have remained in the range of 75% to 85% of the peak DRAM bandwidth of the system over the past 15-20 years — an amazing accomplishment given the increase in core count (with its associated cache coherence issues), number of DRAM channels, and ever-increasing pipelining of the DRAMs themselves.

Benchmarking 97

Benchmarking Cache Latency Tuning 97

Scalegrid

FEBRUARY 8, 2024

Key Takeaways Distributed storage systems benefit organizations by enhancing data availability, fault tolerance, and system scalability, leading to cost savings from reduced hardware needs, energy consumption, and personnel. By implementing data replication strategies, distributed storage systems achieve greater.

Storage 130

Storage Systems Big Data Azure 130

CSS - Tricks

JULY 25, 2019

Cache-Headers missing? Estimated Input Latency. Estimated Input Latency. Service workers that will cache the bytecode result of a parsed and compiled script. After that, it’ll be mitigated by cache. It’s time to come to terms that your customers aren’t using the same powerful hardware as you. Speed Index.

Google 73

Google Engineering Speed Mobile 73

ACM Sigarch

MAY 31, 2023

There are three common mechanisms to access remote memory: modifying applications, modifying virtual memory, and hardware-level cache coherence support. even lowered the latency by introducing a multi-headed device that collapses switches and memory controllers. The recently announced CXL3.0

Latency 52

Latency Hardware Cache Architecture 52

SQL Performance

APRIL 27, 2020

Gen 5 is the primary hardware option now for most regions since Gen 4 is aging out. Hyperscale achieves high performance from each compute node having SSD-based caches which helps minimize the network round trips to fetch data. New Hardware Configuration for Provisioned Compute Tier. GB per vCore.

Azure 55

Azure Database Serverless Hardware 55

Brendan Gregg

AUGUST 18, 2019

For example, iostat(1), or a monitoring agent, may tell you your average disk latency, but not the distribution of this latency. For smaller environments, it can be of more use helping eliminate latency outliers. hardware Hardware counter-based instrumentation. Block I/O latency as a histogram.

Latency 57

Latency C++ Cache Programming 57

Alex Russell

APRIL 29, 2021

For heavily latency-sensitive use-cases like WebXR, this is a critical component in delivering a good experience. An extension to Service Workers that enables browsers to present users with cached content when offline. is access to hardware devices. Some commenters appear to confuse unlike hardware for differences in software.

Media 145

Media Games Education Engineering 145

The Morning Paper

NOVEMBER 5, 2019

Breaking that assumption allowed Ceph to introduce a new storage backend called BlueStore with much better performance and predictability, and the ability to support the changing storage hardware landscape. But let’s take a quick look at the changing hardware landscape before we go on… The changing hardware landscape.

Storage 64

Storage Systems Hardware Efficiency 64

The Morning Paper

APRIL 14, 2019

The paper sets out what we can do in software given today’s hardware, and along the way also highlights areas where cooperation from hardware will be needed in the future. cache) can be partitioned across domains; for those that are instead time-multiplexed, we have to flush them during domain switches. Threat scenarios.

Hardware 44

Hardware Cache Latency Speed 44

Percona

SEPTEMBER 1, 2023

This results in expedited query execution, reduced resource utilization, and more efficient exploitation of the available hardware resources. This reduction in latency ensures that applications and websites provide a more rapid and responsive user experience. Another highly beneficial caching method is key-value caching.

Tuning 52

Tuning Database Performance Hardware 52

The Morning Paper

DECEMBER 10, 2019

. …software operating on persistent data structures requires "global" pointers that remain valid after a process terminates, while hardware requires that a diverse set of devices all have the same mappings they need for bulk transfers to and from memory, and that they be able to do so for a potentially heterogeneous memory system.

Hardware 52

Hardware Virtualization Operating System Programming 52

John McCalpin

AUGUST 1, 2018

According to Dr. Bandwidth, performance analysis has two recurring themes: How fast should this code (or “simple” variations on this code) run on this hardware? The user environment defines the mapping of MPI ranks to hardware resources (cores, sockets, nodes). The MPI runtime library. in ways that are seldom transparent.

Hardware 40

Hardware Transportation Performance Latency 40

John McCalpin

AUGUST 1, 2018

According to Dr. Bandwidth, performance analysis has two recurring themes: How fast should this code (or “simple” variations on this code) run on this hardware? The user environment defines the mapping of MPI ranks to hardware resources (cores, sockets, nodes). The MPI runtime library. in ways that are seldom transparent.

Hardware 40

Hardware Transportation Performance Latency 40

The Morning Paper

MAY 14, 2019

Last time around we looked at the DeathStarBench suite of microservices-based benchmark applications and learned that microservices systems can be especially latency sensitive, and that hotspots can propagate through a microservices architecture in interesting ways. on end-to-end latency) and less than 0.15% on throughput.

Big Data 45

Big Data Cloud Performance Hardware 45

The Morning Paper

DECEMBER 8, 2019

Byte-addressable non-volatile memory,) NVM will fundamentally change the way hardware interacts, the way operating systems are designed, and the way applications operate on data. Therefore any programming abstraction must be low latency and the kernel needs to be kept off the path of persistent data access as much as possible.

Hardware 56

Hardware Programming Media Storage 56

Abhishek Tiwari

DECEMBER 27, 2017

It offers reliability and performance of a data warehouse, real-time and low-latency characteristics of a streaming system, and scale and cost-efficiency of a data lake. Apache Arrow's in-memory columnar layout is specifically optimized for data locality for better performance on modern hardware like CPUs and GPUs.

Big Data 49

Big Data Artificial Intelligence Storage Hardware 49

Alex Russell

OCTOBER 22, 2017

It simulates a link with a 400ms RTT and 400-600Kbps of throughput (plus latency variability and simulated packet loss). Simulated packet loss and variable latency, however, can make benchmarking extremely difficult and slow. Our baseline, then, should probably trade lower throughput/higher-latency for packet loss.

Performance 74

Performance Network Benchmarking Mobile 74

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

John McCalpin

NOVEMBER 5, 2016

These cores have 2 functional units supporting Vector Fused Multiply-Add instructions, with 5-cycle latency on Haswell/Broadwell and 4-cycle latency on Skylake processors (ref: [link] ). With 2 FMA units that have 5-cycle latency, the code must implement at least 2*5=10 independent accumulators in order to avoid stalls.

Cache 40

Cache C++ Latency Hardware 40

The Morning Paper

NOVEMBER 14, 2019

The ability of a datacenter to handle traffic changes over time as capacity is added or removed, and hardware upgraded The routing needs to be able to tolerate failures without making the situation worse. Sharing is caring caching. For example, balance utilisation across all data centers, or optimise for network latency.

Traffic 42

Traffic Internet Internet Latency 42

SQL Server According to Bob

JANUARY 11, 2020

Stable media is commonly physical disk storage, but other devices and certain caching facilities qualify as well. Many high-end disk subsystems provide high-speed cache facilities to reduce the latency of read and write operations. This cache is often supported by a battery-powered backup facility.

Servers 40

Servers Cache Media Hardware 40

KeyCDN

JULY 11, 2019

Using an image CDN, such as KeyCDN, can significantly reduce the latency of your image delivery. This is crucial due to mobile devices requiring additional optimizations because they typically have less powerful hardware and a slower network connection when compared to desktop devices. Mbps ( Opensignal ).

Speed 52

Speed Website Mobile Latency 52

Highly Scalable

AUGUST 20, 2013

This system has been designed to supplement and succeed the existing Hadoop-based system that had too high latency of data processing and too high maintenance costs. In many cases join is performed on a finite time window or other type of buffer e.g. LFU cache that contains most frequent tuples in the stream.

Big Data 154

Big Data Processing Lambda Database 154

The Netflix TechBlog

NOVEMBER 9, 2022

A quick canary test was free of errors and showed lower latency, which is expected given that our standard canary setup routes an equal amount of traffic to both the baseline running on 4xl and the canary on 12xl. What’s worse, average latency degraded by more than 50%, with both CPU and latency patterns becoming more “choppy.”

Hardware 363

Hardware Cache Performance Latency 363

John McCalpin

APRIL 25, 2023

For most high-end processors these values have remained in the range of 75% to 85% of the peak DRAM bandwidth of the system over the past 15-20 years — an amazing accomplishment given the increase in core count (with its associated cache coherence issues), number of DRAM channels, and ever-increasing pipelining of the DRAMs themselves.

Benchmarking 40

Benchmarking Cache Latency Tuning 40

Adrian Cockcroft

SEPTEMBER 23, 2024

The first effect is that the FP4 model weights are 4bits rather than 8bits, so they are half the size, and that means they load twice as fast, with better cache hit rates for the same number of model parameters. These line up much better with what Id expect from the hardware capabilities. The comparisons Ive labeled are 5.3x

Benchmarking 52

Benchmarking Energy Architecture Latency 52

Percona

APRIL 17, 2023

The CFQ works well for many general use cases but lacks latency guarantees. The deadline excels at latency-sensitive use cases ( like databases ), and noop is closer to no schedule at all. Make sure the drives are mounted with noatime and also if the drives are behind a RAID controller with appropriate battery-backed cache.

Best Practices 52

Best Practices Design Tuning Database 52