The CompTIA A+ certification is the most widely recognized entry-level IT credential in the world and the standard baseline requirement for help desk, desktop support, and IT technician roles. The certification requires passing two exams: Core 1 (220-1101) and Core 2 (220-1102). This guide covers the Core 1 exam, which focuses on hardware, networking, mobile devices, cloud computing, and troubleshooting methodology.
CompTIA reports that the A+ certification is held by over 1.3 million IT professionals globally and is recognized by the U.S. Department of Defense under Directive 8570, making it mandatory for certain government IT positions. According to the 2024 CompTIA State of the Tech Workforce report, A+ certified professionals earn a median starting salary of $50,000-$65,000 in the United States, with experienced technicians earning significantly more as they add specializations and higher-tier certifications.
The 220-1101 exam contains up to 90 questions, has a 90-minute time limit, and requires a passing score of 675 out of 900. Questions include multiple choice, drag-and-drop, and performance-based questions (PBQs) that simulate real-world IT scenarios.
Exam Structure and Domains
| Detail | Information |
|---|---|
| Exam Code | 220-1101 |
| Full Name | CompTIA A+ Core 1 |
| Number of Questions | Up to 90 |
| Time Limit | 90 minutes |
| Passing Score | 675/900 |
| Cost | $358 USD |
| Prerequisites | None (6-12 months of hands-on experience recommended) |
| Validity | 3 years (renewable through CEs or retaking) |
The five exam domains:
- Mobile Devices (15%)
- Networking (20%)
- Hardware (25%)
- Virtualization and Cloud Computing (11%)
- Hardware and Network Troubleshooting (29%)
The troubleshooting domain at 29% is the largest, which means nearly a third of the exam tests your ability to diagnose and resolve problems rather than recite facts. This is a practical exam, and candidates who study only theory without hands-on experience frequently struggle.
"The CompTIA A+ is not a memorization test. It is a competency test. The performance-based questions require you to actually solve problems in simulated environments. Candidates who have taken apart a computer, configured a home network, and troubleshot real issues pass. Candidates who only read flashcards fail." -- Mike Meyers, author of the CompTIA A+ Certification All-in-One Exam Guide and founder of Total Seminars
Domain 1: Mobile Devices (15%)
Laptop Hardware
The exam tests your knowledge of laptop-specific hardware components and how they differ from desktop equivalents:
- SODIMMs vs. DIMMs: Laptops use Small Outline Dual In-Line Memory Modules, which are approximately half the physical size of desktop DIMMs. DDR4 SODIMMs have 260 pins, while DDR5 SODIMMs have 262 pins.
- M.2 drives: The primary storage interface in modern laptops, replacing the older 2.5-inch SATA form factor. M.2 drives can use either SATA or NVMe protocols. NVMe (Non-Volatile Memory Express) -- a storage protocol designed specifically for flash-based storage that communicates directly over the PCIe bus, delivering significantly faster read/write speeds than SATA (up to 7,000 MB/s vs. 550 MB/s for SATA).
- Displays: Understanding LCD (uses a backlight, typically LED) vs. OLED (self-emitting pixels, no backlight), touch screen digitizers, and display connector types (LVDS for internal, USB-C/HDMI for external).
Mobile Device Configuration
- Set up email accounts using IMAP, POP3, or Exchange ActiveSync
- Configure WiFi and cellular connections including hotspot functionality
- Synchronize data with cloud services and desktop applications
- Configure location services and understand the GPS, cellular triangulation, and WiFi positioning methods
Mobile Device Accessories
- Docking stations: Provide desktop-like connectivity (multiple monitors, USB devices, ethernet) through a single connection, typically USB-C or Thunderbolt
- Port replicators: Simpler than docking stations, they replicate the laptop's ports for convenient connection/disconnection
- Trackpad and pointing devices: Understanding the variety of input methods including trackpads, pointing sticks, and touch screens
Domain 2: Networking (20%)
TCP/IP Fundamentals
TCP/IP (Transmission Control Protocol/Internet Protocol) -- the foundational protocol suite for internet communication, consisting of four layers: Network Access, Internet, Transport, and Application.
Key protocols and port numbers you must know for the exam:
| Protocol | Port | Purpose |
|---|---|---|
| HTTP | 80 | Unencrypted web traffic |
| HTTPS | 443 | Encrypted web traffic (TLS/SSL) |
| FTP | 20/21 | File transfer |
| SSH | 22 | Secure remote access |
| Telnet | 23 | Unencrypted remote access (legacy) |
| SMTP | 25 | Sending email |
| DNS | 53 | Domain name resolution |
| DHCP | 67/68 | Automatic IP configuration |
| POP3 | 110 | Receiving email |
| IMAP | 143 | Receiving email (server-synced) |
| SNMP | 161/162 | Network management |
| LDAP | 389 | Directory services |
| RDP | 3389 | Remote Desktop Protocol |
Network Hardware
- Routers: Operate at Layer 3 (Network), forward packets between different networks based on IP addresses
- Switches: Operate at Layer 2 (Data Link), forward frames within a network based on MAC addresses. Managed switches allow VLAN configuration and port monitoring.
- Access points: Provide wireless network connectivity. The exam covers
802.11a/b/g/n/ac/axstandards and their frequencies and speeds. - Firewalls: Filter network traffic based on rules. Can be hardware appliances or software running on a server. Stateful firewall -- a firewall that tracks the state of active connections and makes filtering decisions based on the context of the traffic, not just individual packets.
Network Types and Topologies
- LAN (Local Area Network): A network within a single building or campus
- WAN (Wide Area Network): A network spanning multiple geographic locations
- WLAN (Wireless LAN): A LAN using wireless connections
- MAN (Metropolitan Area Network): A network spanning a city or metro area
- PAN (Personal Area Network): A network within personal reach, typically Bluetooth or NFC
IP Addressing Basics
You must understand:
- IPv4 address classes (Class A:
1.0.0.0-126.0.0.0, Class B:128.0.0.0-191.255.0.0, Class C:192.0.0.0-223.255.255.0) - Private IP address ranges (
10.0.0.0/8,172.16.0.0/12,192.168.0.0/16) - Basic subnetting: calculating hosts per subnet from a subnet mask
- APIPA (Automatic Private IP Addressing):
169.254.0.0/16addresses assigned when DHCP is unavailable
Domain 3: Hardware (25%)
Motherboards and CPUs
Form factor -- the physical size, shape, and layout specification of a motherboard that determines case compatibility and expansion options. Common form factors include ATX (305 x 244 mm), Micro-ATX (244 x 244 mm), and Mini-ITX (170 x 170 mm).
CPU concepts for the exam:
- Multi-core processors: Modern CPUs contain multiple processing cores (4, 8, 16, or more) that handle tasks in parallel
- Hyper-Threading (Intel) / SMT (AMD): Technology that allows each physical core to handle two threads simultaneously, effectively doubling the number of logical processors
- Thermal solutions: Heat sinks, fans, liquid cooling, and thermal paste. Proper thermal management prevents throttling and hardware failure.
- CPU sockets: Intel uses LGA (Land Grid Array) sockets like
LGA 1700for 12th-14th generation processors. AMD uses AM5 for Ryzen 7000 series.
RAM Types and Specifications
| RAM Type | Speed Range | Pins (DIMM) | Voltage |
|---|---|---|---|
| DDR3 | 800-2133 MHz | 240 | 1.5V |
| DDR4 | 2133-5100 MHz | 288 | 1.2V |
| DDR5 | 4800-8400+ MHz | 288 | 1.1V |
| DDR3 SODIMM | 800-2133 MHz | 204 | 1.5V |
| DDR4 SODIMM | 2133-5100 MHz | 260 | 1.2V |
RAM generations are not backward compatible. DDR4 will not physically fit in a DDR3 slot due to different notch positions on the module.
Storage Technologies
- HDD (Hard Disk Drive): Mechanical spinning platters with read/write heads. 5400 RPM for laptops, 7200 RPM for desktops. Higher capacity at lower cost but slower than SSDs.
- SSD (Solid State Drive): Flash-based storage with no moving parts. Available in 2.5-inch SATA, M.2 SATA, and M.2 NVMe form factors.
- RAID configurations:
RAID 0(striping, performance, no redundancy),RAID 1(mirroring, redundancy),RAID 5(striping with parity, requires 3+ drives),RAID 10(mirroring + striping, requires 4+ drives)
Power Supplies
- ATX power supply delivers +3.3V, +5V, and +12V to components
- Power supplies are rated in watts. A typical desktop needs 450-750W depending on the GPU
- 80 Plus certification rates power supply efficiency: 80 Plus, Bronze, Silver, Gold, Platinum, Titanium (ranging from 80% to 96% efficiency at 50% load)
- Modular power supplies allow unused cables to be disconnected, improving airflow
Peripheral Devices and Connectors
Key connector types:
- USB-A: Standard rectangular connector, USB 2.0 (480 Mbps), USB 3.0 (5 Gbps)
- USB-C: Reversible connector supporting USB 3.2 (up to 20 Gbps), Thunderbolt 3/4 (up to 40 Gbps), and DisplayPort Alt Mode
- HDMI: Video and audio output, versions 1.4 through 2.1 (up to 8K resolution)
- DisplayPort: Video output preferred for high refresh rate monitors, supports daisy-chaining
- Lightning: Apple proprietary connector being phased out in favor of USB-C
Domain 4: Virtualization and Cloud Computing (11%)
Virtualization Concepts
Hypervisor -- software that creates and manages virtual machines by abstracting physical hardware. Type 1 (bare-metal) hypervisors like VMware ESXi and Microsoft Hyper-V run directly on hardware. Type 2 (hosted) hypervisors like VirtualBox and VMware Workstation run on top of an existing operating system.
Key virtualization concepts:
- Virtual machine (VM): A software-based computer that runs an operating system and applications as if it were a physical machine
- Resource allocation: Assigning CPU cores, RAM, storage, and network adapters to VMs
- Snapshots: Point-in-time copies of a VM's state that allow quick rollback if something goes wrong
- Network virtualization: Virtual switches and virtual NICs that allow VMs to communicate with each other and the physical network
Cloud Computing Models
The exam tests the same IaaS, PaaS, SaaS models covered in other certifications, applied to practical IT support scenarios:
- IaaS: Amazon EC2, Microsoft Azure VMs, Google Compute Engine. The IT technician manages the OS and applications.
- PaaS: AWS Elastic Beanstalk, Azure App Service, Google App Engine. Developers deploy code without managing the underlying infrastructure.
- SaaS: Microsoft 365, Google Workspace, Salesforce. End users access applications through a web browser.
- Cloud deployment models: Public (shared infrastructure), Private (dedicated infrastructure), Hybrid (combination), Community (shared among organizations with common requirements)
Amazon Web Services, which pioneered the public cloud market in 2006, held approximately 31% of global cloud infrastructure market share in 2024 according to Synergy Research Group. Microsoft Azure held 25%, and Google Cloud held 11%.
Domain 5: Hardware and Network Troubleshooting (29%)
This is the highest-weighted domain and the one that most directly tests practical competence.
The CompTIA Troubleshooting Methodology
Memorize and apply this six-step process:
- Identify the problem: Gather information from the user, establish a theory, and question the obvious
- Establish a theory of probable cause: Start with the simplest explanation (check cables, check power, check settings)
- Test the theory: If the theory is confirmed, determine the next steps. If not, re-establish a new theory.
- Establish a plan of action: Create a resolution plan and implement it
- Verify full system functionality: Confirm the fix resolved the issue and did not create new problems. Implement preventive measures.
- Document findings, actions, and outcomes: Create a record for future reference and organizational knowledge
Common Hardware Issues
- Blue Screen of Death (BSOD): Usually caused by driver conflicts, faulty RAM, or failing storage. Test RAM with Windows Memory Diagnostic or
memtest86. Check storage health with CrystalDiskInfo or manufacturer tools. - Overheating: Symptoms include random shutdowns, throttling, and loud fan noise. Clean dust from vents and heat sinks, replace thermal paste, and verify fan operation.
- No POST (Power-On Self-Test): Verify power connections, reseat RAM and GPU, check for motherboard indicator LEDs or beep codes.
- Slow performance: Check Task Manager for resource utilization. Common causes include insufficient RAM, failing HDD, malware, and excessive startup programs.
Professor David Hucaby, who teaches networking and IT courses at multiple universities and has authored Cisco Press study materials, emphasizes that "troubleshooting is a skill that only develops through practice. Reading about the troubleshooting methodology is step one. Applying it to real broken systems is where competence actually forms. Every A+ candidate should have a test lab, even if it is just an old computer they can take apart and reassemble."
Common Network Issues
- No connectivity: Check physical connections, verify IP configuration with
ipconfig(Windows) orifconfig/ip addr(Linux), test DNS withnslookup, test connectivity withpingandtracert/traceroute - Intermittent connectivity: Often caused by WiFi interference, failing cables, or DHCP lease issues
- Slow network: Check for bandwidth saturation, duplex mismatches, or interference on wireless channels
- DNS failures: Symptoms include inability to reach websites by name while IP addresses work. Verify DNS server settings and test with
nslookup
Study Plan and Resources
Six-Week Study Plan
- Week 1: Mobile Devices. Study laptop hardware, mobile device configuration, and accessories.
- Week 2: Networking fundamentals. Learn TCP/IP, ports, network hardware, and IP addressing.
- Weeks 3-4: Hardware. This is the largest domain. Study motherboards, CPUs, RAM, storage, power supplies, and peripherals. Hands-on practice is essential.
- Week 5: Virtualization and cloud computing. Set up VirtualBox and create a VM. Study cloud models.
- Week 6: Troubleshooting. Practice the methodology. Take practice exams. Review weak areas.
Recommended Resources
- CompTIA A+ Certification All-in-One Exam Guide by Mike Meyers -- the most popular A+ study guide, known for its accessible writing style
- Professor Messer's CompTIA A+ course on YouTube (free): Comprehensive, well-organized video series that covers every exam objective
- CompTIA CertMaster Practice: Official practice tests from CompTIA
- Dion Training practice exams on Udemy: Jason Dion's practice tests are among the most recommended in the A+ community
- Build a PC: If you have not built a computer from parts, doing so once is the single most effective study activity for the hardware domain
Performance-Based Question Strategy
The 220-1101 exam includes performance-based questions (PBQs) that present simulated environments where you must complete a task rather than select an answer. PBQs typically appear at the beginning of the exam and can cover scenarios like configuring a wireless network, setting up email on a mobile device, troubleshooting a hardware issue, or matching ports to protocols.
Strategy for PBQs:
- Skip PBQs on your first pass through the exam if they are taking too long. Answer the multiple-choice questions first to secure points, then return to PBQs with remaining time.
- Read the instructions carefully. PBQs often have specific requirements that are easy to overlook if you rush.
- Practice with simulation-based labs before exam day. CompTIA CertMaster Labs and TestOut PC Pro are both platforms that offer PBQ-style hands-on exercises.
- Remember that partial credit may be awarded on PBQs. Even if you cannot complete the entire scenario, completing as many correct steps as possible is better than leaving it blank.
See also: CompTIA A+ Core 2 220-1102 study guide, CompTIA Network+ certification path, IT career roadmap from help desk to systems administrator
References
- CompTIA. "CompTIA A+ Certification Exam Objectives (220-1101)." CompTIA, 2025.
- Meyers, Mike. CompTIA A+ Certification All-in-One Exam Guide, Eleventh Edition. McGraw-Hill, 2023.
- CompTIA. "State of the Tech Workforce Report 2024." CompTIA Research, 2024.
- Synergy Research Group. "Cloud Infrastructure Market Share Q4 2024." Synergy Research, 2024.
- U.S. Department of Defense. "DoD Directive 8570: Information Assurance Workforce Improvement Program." DoD, updated 2023.
- Prowse, David. CompTIA A+ Exam Cram. Pearson IT Certification, 2023.
Frequently Asked Questions
How hard is the CompTIA A+ Core 1 exam?
The A+ Core 1 is considered entry-level but should not be underestimated. It covers a broad range of hardware, networking, and troubleshooting topics. Most candidates need 4-6 weeks of focused study. Performance-based questions require practical problem-solving skills, not just memorization.
What is the passing score for CompTIA A+ Core 1?
You need a score of 675 out of 900 to pass the 220-1101 exam. The exam contains up to 90 questions including multiple choice, drag-and-drop, and performance-based questions, with a 90-minute time limit.
Is CompTIA A+ enough to get an IT job?
Yes, CompTIA A+ is sufficient for entry-level IT positions including help desk technician, desktop support specialist, and IT support roles. It is the most requested certification in entry-level IT job postings and meets DoD 8570 requirements for certain government IT positions.