hardMultiple ChoiceObjective-mapped
220-1201 Practice Question: A technician is configuring a high-performance…
A technician is configuring a high-performance workstation for scientific simulations that require large amounts of RAM. The motherboard has eight DDR4 slots and supports quad-channel memory. The technician installs four 16 GB sticks in the correct slots for quad-channel mode. After booting, the system reports 64 GB of RAM but only runs in dual-channel mode. What is the most likely cause?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The installed CPU only supports dual-channel memory.
Quad-channel memory requires a compatible CPU that supports quad-channel architecture. Most consumer CPUs (like Intel Core i7/i9) only support dual-channel, even if the motherboard has four slots. Server or HEDT (High-End Desktop) CPUs are needed for quad-channel.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The RAM sticks are not identical in speed and timings.
Why it's wrong here
While mismatched RAM modules can indeed cause system instability, force all modules to operate at the lowest common speed and highest common latency, or even prevent the system from booting entirely, this is not the issue here. The technician explicitly installed four identical RAM sticks, ensuring uniformity in speed, timings, and capacity. Therefore, the system's inability to achieve quad-channel mode is not attributable to non-identical memory modules.
- ✗
The motherboard BIOS needs to be configured to enable quad-channel mode.
Why it's wrong here
Memory channel configuration, such as dual-channel or quad-channel mode, is primarily an automatic function determined by the CPU's integrated memory controller (IMC) and the motherboard's design. When the CPU supports a specific channel mode and the RAM is installed correctly in the appropriate slots, the system automatically detects and enables it. There is typically no specific BIOS setting that needs to be manually configured to 'enable' quad-channel mode; the BIOS merely reports the detected memory configuration.
- ✓
The installed CPU only supports dual-channel memory.
Why this is correct
The CPU's integrated memory controller (IMC) is the fundamental component that dictates the maximum number of memory channels a system can utilize. Even if a motherboard is physically capable of supporting quad-channel memory and four identical RAM sticks are installed, a CPU designed with only a dual-channel IMC will inherently limit the system to operating in dual-channel mode. The additional RAM will still be recognized and usable, but it will be accessed through the existing two channels, not an expanded quad-channel configuration.
- ✗
The RAM is installed in the wrong slots for quad-channel operation.
Why it's wrong here
For multi-channel memory configurations like quad-channel, RAM modules must be installed in specific, often color-coded, slots according to the motherboard manual to ensure proper channel interleaving and optimal performance. Incorrect slot placement would typically result in the system either failing to boot, recognizing only a portion of the installed RAM, or operating in a lower channel mode (e.g., single-channel). However, the technician verified the correct slot usage, and the system recognized all 64 GB of RAM, indicating the physical installation was correct.
Go deeper
Related to this question
Learn chapter
Motherboard Components and Form Factors
Key term
CPU
The Central Processing Unit (CPU) is the main electronic brain of a computer that carries out instructions from software by performing basic arithmetic, logic, control, and input/output operations.
Key term
Motherboard
The main circuit board inside a computer that connects all components so they can communicate with each other and receive power.
About these practice questions
Courseiva writes every 220-1201 question from scratch — 972 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1201 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1201 exam.