Performance Tuning

Maximizing 40G NIC Performance on Linux with Intel XL710 and Cisco Nexus Switches

06/16/2025 06/16/2025 / By Klaus Aschenbrenner / Linux, Performance Tuning / Leave a Comment

In this comprehensive technical walkthrough, I’ll take you through a real-world journey of troubleshooting and tuning a high-performance 40 Gbit Ethernet setup using Intel XL710 network cards connected through a Cisco Nexus 3064 switch. The goal was simple but challenging: to achieve near line-rate performance using iperf3 between two Linux (Proxmox) systems. When I first started testing …

Maximizing 40G NIC Performance on Linux with Intel XL710 and Cisco Nexus Switches + read more

Why I Created the SQL Rescue Sprint – And How It Works

06/04/2025 06/04/2025 / By Klaus Aschenbrenner / Performance Tuning, SQLServer / Leave a Comment

Over the past 25 years, I’ve worked with SQL Server in all kinds of environments: startups, mid-size companies, and global enterprises. And no matter the industry or infrastructure, one thing is always true: When SQL Server slows down, everything slows down! Reports take forever. Blocking brings processes to a halt. Deadlocks frustrate both users and …

Why I Created the SQL Rescue Sprint – And How It Works + read more

Heap Tables

03/01/2022 03/01/2022 / By Klaus Aschenbrenner / Performance Tuning, SQLServer / Leave a Comment

In today’s blog posting I want to talk about Heap Tables in SQL Server. Heap tables are tables without a Clustered Index. A table in SQL Server can have a Clustered Index, then it’s called a Clustered Table, and without a Clustered Index, it’s called a heap table. In a heap table, the data is …

Heap Tables + read more

Data Page Restrictions

02/21/2022 02/21/2022 / By Klaus Aschenbrenner / Performance Tuning, SQLServer / Leave a Comment

Today I’m talking about limitations that you have with data pages, and why there are restrictions that you will love, while you will hate other restrictions. As you learned, a data page is always 8kb large, and you can store 8060 bytes of data on it. And the size of your records dictates how many …

Data Page Restrictions + read more

Extent Management in SQL Server

02/14/2022 02/14/2022 / By Klaus Aschenbrenner / Performance Tuning, SQLServer / Leave a Comment

Today I’m talking about Extent Management in SQL Server, because this is a very important topic, especially when you deal with TempDb in SQL Server. On a very high level an extent is just a group of 8 pages of 8kb. An extent is therefore always a chunk of 64kb. SQL Server internally implements 2 …

Extent Management in SQL Server + read more

SQLpassion Performance Tuning Training Plan – Signup