SIEM vs MDR vs XDR for Texas SMBs: What Each Costs and What Each Catches

SIEM — Security Information and Event Management

A platform that ingests logs from many sources (firewalls, endpoints, servers, identity, cloud) and runs correlation rules to surface alerts. Splunk, Microsoft Sentinel, Sumo Logic, IBM QRadar, Elastic SIEM, Wazuh. SIEM is a tool, not a service. Someone has to write rules, tune thresholds, triage alerts, and chase down detections.

MDR — Managed Detection and Response

An outsourced security operations service. The MDR provider deploys their own sensor stack (or leverages your existing tools), runs 24/7 SOC monitoring, and either notifies you of incidents or performs response actions on your behalf. Arctic Wolf, Rapid7 MDR, CrowdStrike Falcon Complete, Sophos MDR, Huntress, Blackpoint, Expel. MDR is a service with technology underneath.

XDR — Extended Detection and Response

A unified detection-and-response platform that natively correlates across endpoint, identity, email, cloud, and (sometimes) network telemetry. Microsoft Defender XDR, CrowdStrike Falcon, SentinelOne Singularity, Palo Alto Cortex XDR. XDR is a platform; it can be self-managed or wrapped in MDR.

SIEM

• Microsoft Sentinel: $1.50-$2.50 per GB ingested + analytics. For a typical 50-user environment: $800-$2,500/month for the platform
• Splunk: highly variable, generally $5K-$25K/month for SMB-scale deployments
• Wazuh / Elastic SIEM: open source; infrastructure + 0.5 FTE security engineer (so $80K-$130K/year fully loaded)
• Hidden cost: SIEM without a SOC behind it is mostly noise. Self-managed SIEM is rarely cost-effective for SMBs without dedicated security headcount

MDR

• $15-$45 per endpoint per month, depending on provider and tier
• For 100 endpoints: $1,500-$4,500/month all-in
• Includes 24/7 SOC, incident response, often retainer hours for major incidents
• Hidden cost: response action latitude varies widely. Some MDR providers only alert; others can isolate hosts. Get this in writing

XDR

• Microsoft Defender for Endpoint Plan 2: included in M365 E5; standalone roughly $5/user/month
• Defender for Office 365 P2: $5/user/month
• Defender for Identity: $5/user/month
• Bundled M365 E5 Security: ~$12/user/month — gets you the full Microsoft XDR stack
• CrowdStrike Falcon: $8-$25 per endpoint depending on modules
• SentinelOne Singularity: $5-$20 per endpoint

Pick MDR if:

• You have no in-house security operations capability
• You are subject to compliance frameworks requiring 24/7 monitoring (CMMC, SOC 2, PCI)
• You want defined response actions, not just alerts
• You are 25-500 employees without a dedicated security analyst

Pick XDR if:

• You are heavily Microsoft 365 invested (Defender XDR with M365 E5 is hard to beat for the price)
• You have at least one technical person who can triage alerts
• You want native correlation across endpoint + identity + email
• You can pair XDR with an MDR layer if 24/7 coverage is required

Pick SIEM if:

• You have specific log retention requirements (often regulatory)
• You need to ingest logs from non-standard sources
• You have dedicated security engineering headcount to operate it
• You are large enough (250+ employees) that the customization payoff exists

The Common Texas SMB Answer

For most Texas SMBs in the 25-250 employee range, the right architecture is: XDR (Defender or CrowdStrike) for the platform, MDR wrapper for 24/7 monitoring. SIEM only if compliance forces it. This combination delivers most of the detection coverage with predictable cost and accountable response.

• Buying SIEM and assuming detection happens automatically. SIEM without a SOC is a log archive
• Layering three tools that overlap. Defender XDR + Splunk + a separate MDR all watching the same telemetry is wasted spend
• Ignoring response authority. Detection without authorized response is just expensive observation

Texas SMBs evaluating detection-and-response should map their actual current coverage gaps before adding tools. A vCISO assessment scopes the right architecture in 1-2 weeks. See our vCISO service, threat monitoring, and cybersecurity services overview. For broader stack design context: PAM tools comparison and the 2026 Texas SMB Benchmark Report.

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