Identifying Common SCM Media Types in Huawei Storage
Short answer
BCD PCRAM, MRAM, and ReRAM are common SCM media types, whereas DRAM is volatile.
Question
Key Takeaways
The main trap is including DRAM; remember that SCM must be non-volatile, unlike traditional RAM.
Learn which memory technologies qualify as Storage Class Memory (SCM). This page explains why PCRAM, MRAM, and ReRAM are correct while DRAM is excluded due to volatility.
Common mistake: Selecting DRAM (A) because it is fast memory, failing to recognize that SCM requires non-volatility for persistence.
Expert Analysis
The question asks to identify common types of Storage Class Memory (SCM) media. SCM is a tier of storage that bridges the gap between volatile DRAM and non-volatile NAND flash, offering byte-addressability like memory but with persistence like storage.
Option A, Dynamic random-access memory (DRAM), is incorrect because it is volatile; its data is lost when power is removed. While fast, it does not meet the persistence requirement inherent to SCM definitions in modern storage architectures. Comments from Huawei documentation confirm that "DRAM is not one of them" and classify it as traditional volatile memory.
Options B, C, and D are correct. Phase-change memory (PCRAM), Magnetoresistive random-access memory (MRAM), and Resistive random-access memory (ReRAM) are all emerging non-volatile memory technologies designed to serve as SCM. They offer the speed close to DRAM while maintaining data retention without power, fitting the SCM use case perfectly.
The core concept here is distinguishing between volatile main memory (DRAM) and persistent, high-speed intermediate storage (SCM). The trap is assuming all high-speed memories are SCM, forgetting that persistence is a key differentiator.
Exam Strategy
When asked about Storage Class Memory, always filter options by persistence. If an option describes volatile memory (like DRAM or SRAM), exclude it immediately. Focus on emerging non-volatile technologies such as PCM, MRAM, ReRAM, and NVRAM variants.
Frequently Asked Questions
Why is DRAM not considered SCM?
What are the main types of SCM?
Community Votes
34% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.
Discussion 2 contributions
Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.
From public community threads 2
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10c5cfe 👍 1from huawei documentation: (DRAM is not one of them.) There are various types of SCM media under development, but the mainstream SCM media are PCRAM, ReRAM, MRAM, and NRAM.
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gcerchiaro21 👍 1DRAM es volátil y se clasifica como memoria tradicional, no como SCM.
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