Microsoft Sentinel vs. Traditional SIEMs

It’s no secret that the past two years have reshaped how we engage in work and think about security, accelerating the widespread adoption of cloud and remote-access solutions. The security perimeter of today’s workplace extends far beyond the office, and organisations require a security solution that’s able to keep pace with flexible working patterns and provide a centralised view across a decentralised digital estate.

Introducing Microsoft Sentinel, Microsoft’s cloud-native Security Information and Event Management (SIEM) and Security orchestration, automation and response (SOAR) solution.

In this article, we’ll cover the key differences between traditional, on-premises SIEM solutions and Microsoft Sentinel – Microsoft’s cloud-native SIEM solution.

What are SIEMs and SOARs?

SIEM, or Security Information and Event Management, is a security system that assists organisations in identifying possible security threats and vulnerabilities before they interrupt business operations. It detects anomalous user behavior and uses artificial intelligence to automate many of the manual processes associated with threat detection and incident response. It has become a staple in modern security operation centers (SOCs) for security and compliance management use cases.

SOAR, or Security Orchestration, Automation, and Response, refers to technologies that allow businesses to collect inputs that are monitored by the security operations team. Alerts from the SIEM system and other security technologies help define, prioritise and drive standardised incident response activities by employing a combination of human and machine power.

What is Microsoft Sentinel?

Microsoft Sentinel is a cloud-native SIEM and SOAR solution that gives you a birds-eye view across your organisation’s entire technology ecosystem. It monitors signals and data from all applications, services, infrastructure, networks, and users – irrespective of if it exists in Azure, on-prem or other cloud services.

Where Sentinel fits in with your security stack

Microsoft Sentinel sits at the very top of your security ecosystem by integrating and gathering data from all your existing security solutions. Meaning, the more security solutions you have in place, the more value Sentinel can provide. Sentinel leverages AI and machine learning that’s been built up over the past decade, Sentinel scans all the signals from your environment and only alerts you of the critical security events that require your attention.

How Microsoft Sentinel compares to traditional SIEMs

Is now the perfect time to ditch your traditional SIEM solution for Microsoft Sentinel? We’ll let you decide by comparing the two on a cost, usability, performance and ease of deployment basis. Let’s dive straight into it.


A key difference between traditional and cloud native SIEMS is start-up costs. On-premises solutions require large capital investment into hardware and software that needs to be manually upgraded and maintained over time. Microsoft Sentinel significantly reduces your infrastructure costs by shifting spend from Capex to Opex. Meaning, you pay for what you use with no up-front costs. In late 2020, Forrester released a report titled The Total Economic Impact of Azure Sentinel, that highlighted the cost benefits of the Sentinel. Here’s what they found:

  • A three-year 201 percent return on investment (ROI) with a payback period of less than six months.
  • A 48 percent reduction in costs compared to legacy SIEM solutions, saving on expenses like licensing, storage, and infrastructure costs.
  • A 79 percent reduction in false positives and 80 percent reduction in the amount of labor associated with investigation, reducing mean time to resolution (MTTR) over three years.
  • A 67 percent decrease in time to deployment compared to legacy on-premises SIEMs.


With traditional SIEM solutions, legitimate behaviours and actions are frequently misclassified as correlated attacks. These alerts are called False Positives, and they drain the time, resources and willpower of the IT teams investigating them. This is commonly referred to as alert fatigue and can cause legitimate threats to dwell in your environment for longer.

Ease of use is a key trend among cloud solutions, and Microsoft Sentinel is no different. Sentinel uses artificial intelligence and machine learning that’s been built up over the past decade to ensure that it only notifies you of the security incidents that require your immediate attention. Thus, eliminating false positives and keeping your IT security teams checked in. And since it’s built on Azure, it offers virtually limitless cloud scale while addressing all your security needs.


Detection analysis in on-premises SIEMs is frequently postponed until traffic flow is less taxing on the system. When the SIEM’s events per second (EPS) were set to their maximum, querying and correlating data became much slower.

Threats can be identified in real-time with a modern cloud based SIEM, such as Microsoft Sentinel, with less bandwidth overhead and enhanced processing power. As logs are delivered into the SIEM, they are analysed instantly. Because the technology is hosted on the Microsoft cloud and scales automatically, the collection of logs has no effect on the speed at which it queries and correlates data.

Ease of deployment

Historically, SIEM solutions were riddled with complications, necessitating a high level of knowledge to deploy and manage. However, today’s cloud based SIEMs are built to be easy to deploy and administer by anyone with a basic understanding of IT. Meaning, organisations do not need to hire additional personnel to manage it. This not only affects the cost of deploying a SIEM, but also the deployment lead times.

The deployment process for an on-premises SIEM is manual and very lengthy. However, due to the nature of SaaS, high availability and ease of deployment comes as part of Microsoft Sentinel’s design. Sentinel allows businesses to swiftly deploy and customise their SIEM. There’s no need to fuss about installing hardware or performing manual maintenance and upgrades. And since it’s built on Azure, it offers virtually limitless cloud scale while addressing all your security needs.

With on-premises SIEMs, keeping up to date with new technologies and capabilities can be overwhelming and often very costly. In contrast, Sentinel takes care of updates and patches for you, without requiring any additional cost or effort.

Common SIEM challenges faced by IT Security professionals

Last year, Panther Labs conducted research that surveyed over 400 security professionals who actively use a traditional SIEM solution as part of their day-to-day work to gain insight into their current SIEM challenges, desires and frustrations. Here’s what they found:

  • 18% of respondents indicated that it took more than 12 months to deploy and implement their SIEM solution
  • 24% said that the biggest challenge with their SIEM platform was too many alerts
  • 46% said that cost of their SIEM solution did not align with its capabilities
  • More than 50% of respondents stated that they are dissatisfied with their current SIEM platform’s visibility
  • The largest group of respondents said big data infrastructure and scalability would be the two most important capabilities if they were evaluating a new SIEM vendor

Looking to trial Microsoft Sentinel for your organisation?

Find out how Microsoft Sentinel could benefit your organisation with our Microsoft Sentinel Cloud Accelerator Workshop. During this workshop, you’ll get an overview of Azure Sentinel along with insights on active threats to your Microsoft 365 cloud and on-premises environments.