John McCalpin

FEBRUARY 17, 2025

Understanding sustained memory bandwidth in these systems starts with assuming 100% utilization and then reviewing the factors that get in the way (e.g., This requires a completely different approach to modeling the memory system — one based on Little’s Law from queueing theory.

Latency 71

Latency Hardware Cache Systems 71

Dynatrace

DECEMBER 22, 2021

Complex information systems fail in unexpected ways. Observability gives developers and system operators real-time awareness of a highly distributed system’s current state based on the data it generates. With observability, teams can understand what part of a system is performing poorly and how to correct the problem.

Artificial Intelligence 245

Artificial Intelligence Metrics Architecture DevOps 245

John McCalpin

FEBRUARY 17, 2025

Understanding sustained memory bandwidth in these systems starts with assuming 100% utilization and then reviewing the factors that get in the way (e.g., This requires a completely different approach to modeling the memory system — one based on Little’s Law from queueing theory.

Latency 40

Latency Hardware Cache Systems 40

SQL Performance

FEBRUARY 22, 2021

The system table sys.sysprocesses was replaced way back in SQL Server 2005 by a set of dynamic management views (DMVs), most notably sys.dm_exec_requests , sys.dm_exec_sessions , and sys.dm_exec_connections. We recommend that you use the current SQL Server system views instead. Why this is a problem.

Latency 57

Latency Servers Monitoring Systems 57

John McCalpin

APRIL 2, 2020

The presentation discusses a family of simple performance models that I developed over the last 20 years — originally in support of processor and system design at SGI (1996-1999), IBM (1999-2005), and AMD (2006-2008), but more recently in support of system procurements at The Texas Advanced Computing Center (TACC) (2009-present).

Benchmarking 59

Benchmarking Performance Latency Architecture 59

John McCalpin

APRIL 2, 2020

The presentation discusses a family of simple performance models that I developed over the last 20 years — originally in support of processor and system design at SGI (1996-1999), IBM (1999-2005), and AMD (2006-2008), but more recently in support of system procurements at The Texas Advanced Computing Center (TACC) (2009-present).

Benchmarking 40

Benchmarking Performance Latency Architecture 40

IO River

NOVEMBER 2, 2023

Therefore, there might be cases where your system could experience a downtime during the migration process. For example, Akamai introduced ASI in 2005, which became the standard for building new websites. These companies often utilize CDNs optimized for low-latency content delivery of the products that they offer.

Lambda 52

Lambda AWS Cache Website 52