WGU D316 CompTIA A+ lesson 2 complete questions with expert solutions + rationales

You are configuring four 120 GB drives in a RAID 5 array. How much space will be available?

360 GB

Why can cache improve performance?

A CPU tends to repeat the same routines and access the same data over and over again. If these routines are stored in fast cache RAM, they can be accessed more quickly than instructions and data stored in system memory.

You are configuring a different workstation with dual-channel memory. You have two modules and there are four slots. How would you determine which slots to use?

Check the vendor's setup/service manual. Many systems will use the slots marked A1 and B1, but it's best not to proceed without consulting the vendor's documentation.

True or false? A solid-state drive (SSD) attached to an M.2 port must be using the non-volatile memory host controller interface specification (NVMHCI) or NVM Express (NVMe).

False. M.2 is a physical form factor and can support both SATA and NVMe interfaces.

True or false? A memory card reader is needed to attach a thumb drive to a PC.

False. A thumb or pen drive will plug into a USB port.

What is the significance of a PSU's wattage rating when you are designing a custom-build PC?

It determines the CPU model and number and type of memory modules, expansion cards, and storage devices that can be installed. The PSU's wattage rating must be higher than the sum of the power requirements of all the PC's components.

Consulting the vendor documentation, you find that this system uses DDR4 error-correcting code (ECC) RDIMMs. The spares you have are DDR4 ECC UDIMMs. Can they be used for the upgrade?

No. If the vendor documentation specifies registered memory (RDIMMs), you must use RDIMM modules. Unbuffered DIMMs (UDIMMs) will not be compatible even if they are ECC.

A workstation has a multi-socket motherboard but only a single LGA 1150 socket is populated. The installed CPU is a Xeon E3-1220. You have a E3-1231 CPU in store that also uses the LGA 1150. Should this be used to enable symmetric multiprocessing and upgrade system performance?

No. The CPU models must be identical. If the CPUs are not identical, the system is unlikely to boot. Even if the system boots, it is not likely to operate reliably.

You need to upgrade the system RAM on a PC. The motherboard has two 8 GB modules of DDR3 RAM installed and two free slots. You have two spare 16 GB DDR4 modules in your stores. Can these be used for this upgrade?

No. The DDR generation of the motherboard slot and modules must match. You can only use DDR3 modules.

You are specifying a computer for use as a software development workstation. This will be required to run multiple virtual machines (VMs). Can any x64-compatible CPU with sufficient clock speed be used?

No. You must verify that the CPU model supports virtualization extensions.

What is the minimum number of disks required to implement RAID 10, and how much of the disks' total capacity will be available for the volume?

RAID 10 requires at least four disks (two mirrored pairs) and comes with a 50% capacity overhead, so the volume will only be half the total disk capacity.

If you have a computer with three hard disks, what type of RAID fault-tolerant configuration will make best use of them?

RAID 5 (striping with parity). RAID 0 is not fault tolerant. RAID 1 and RAID 10 require an even number of disks.

What feature might you look at in selecting a high-performance hard disk drive associated with speed?

Revolutions per minute (RPM) - the speed at which it spins. The top-performing drives are 15,000 (15K) or 10,000 (10K).

What type of memory technology supports paging?

Virtual RAM or virtual memory. The operating system creates a virtual address space for each process. This address space can use physical system random-access memory (RAM) modules and swap space or paging files stored on fixed disks (hard drives and SSDs). Paging moves data between system RAM and the swap space as required.

What must you check when inserting a PGA form factor CPU?

You must check that pin 1 is aligned properly and that the pins on the package are aligned with the holes in the socket. Otherwise, you risk damaging the pins when the locking lever is secured.

Your company has recently closed a foreign branch office, and you are repurposing some PCs that were shipped from the old location. What feature of the PSUs must you check before powering the systems on?

You must check that the voltage selector is set to the correct voltage or, if there is no selector, that the PSU is suitable for the voltage used by the building power circuit.

One of the PCs has a faulty CPU, and one has a faulty power supply. You can use the CPU from one machine in the other. You have opened the case and taken antistatic precautions. What steps mut you perform to access the CPU?

First, you will remove power cables from the motherboard and CPU. Then, you will have to remove the fan and heat-sink assembly, disconnect the fan's power connector, release the pins or screws that attach the assembly to the motherboard, and remove the assembly (a gentle twisting motion may be required if the thermal paste has stuck the heat sink firmly to the CPU).

The repurposed PC is put into service, but later that day the PC's user contacts you to say that the system has been displaying numerous alerts about high temperature. What do you think might be the cause?

You would need to open the case to investigate the problem. Perhaps when the upgrade was performed, one of the fan power connectors was not attached properly, or there could be a fault in the fan on the PSU.

input voltage

Range of alternating current (AC) voltages that a PSU can ACCEPT when connected to grid power. Some PSUs are manually switched between low-line 110-120 VAC and high-line 220-240 VAC.

wattage rating

Measure of how much power can be supplied BY a PSU.

output voltages (3.3 VDC, 5 VDC, and 12 VDC)

Direct current (DC) 3.3 VDC, 5 VDC, and 12 VDC power supplied OVER PSU cables TO computer components

Modular PSU

PSU design where power cables can be attached to ports on the unit as needed.

redundant power supply

System case configuration supporting two power units for fault tolerance.

heat sink

Cooling device fitted to PC components to optimize heat transfer.

thermal paste

Cooling substance applied between a component and heat sink to optimize heat transfer.

fan

Cooling device fitted to PC cases and components to improve air flow.

liquid-based cooling system

Cooling system that uses system of pipes, water blocks, and pumps to transfer heat away from components.

solid-state drive (SSD)

Persistent mass-storage device implemented using flash memory.

mSATA

Connector form factor for internal solid state drives.

NVM Express (NVMe)

Internal interface for connecting flash memory devices, such as SSDs, directly to a PCI Express bus. NVMe allows much higher transfer rates than SATA/AHCI.

hard disk drive (HDD)

Mass storage device that uses mechanical platters with a magnetic coating that are spun under disk heads that can read and write to locations on each platter (sectors).

redundant array of independent disks (RAID)

Specifications use multiple storage devices to protect against data loss in the event of device failure.

Raid 0

Striping drive configuration that provides no redundancy against device failure.

RAID 1

Mirrored two-disk redundant drive configuration with 50% capacity utilization.

RAID 5

Striping with parity-redundant drive configuration supporting a flexible number of devices and better than 50% capacity utilization.

RAID 10

Stripe of mirrored four-disk redundant drive configuration with 50% capacity utilization. A RAID10 volume can support the loss of one device in each mirror.

flash drive

Solid state flash memory provisioned as a peripheral device with a USB interface.

memory card

Solid state flash memory provisioned as a peripheral device in a proprietary adapter card form factors, such as Secure Digital and microSD.

Compact Discs (CDs)

Optical storage technology supporting up to 700 MB per disc with recordable and re-writable media also available.

optical drive

Mass storage device that supports CD, DVD, and/or Blu-ray media. Burner-type drives also support recording and rewriting.

virtual RAM

An OS mediates access to random-access memory (RAM) devices by assigning a virtual address space to each process. As well as protecting memory access, the memory capacity can be extended by configuring a swap space or pagefile on a mass-storage device (HDD or SSD).

Double Data Rate SDRAM (DDR SDRAM)

Series of high-bandwidth system-memory standards (DDR3/DDR4/DDR5) where data is transferred twice per clock cycle.

Small outline DIMM (SODIMM)

System-memory form factor designed for use in laptops.

Single-channel

System-memory controller configuration that provides one data pathway between the memory modules and the CPU.

dual-channel

System-memory controller configuration that provides two data pathways between the memory modules and a compatible CPU.

triple-channel

System-memory controller configuration that provides three data pathways between the memory modules and a compatible CPU.

quadruple-channel

System-memory controller configuration that provides four data pathways between the memory modules and a compatible CPU

Error correcting code (ECC) RAM

System memory (RAM) with built-in error correction security. It is more expensive than normal memory and requires motherboard support. It is typically only used in servers.

x86

The x86 Architecture refers to the way a computer processes information. The x86 instruction set defines a CPU as IBM PC compatible. x86 PC processors are designed and manufactured by Intel and Advanced Micro Devices (AMD).

Intel

Intel processors were used in the first IBM PCs, and the company's CPUs and chipsets continue to dominate the PC and laptop market.

Advanced Micro Devices (AMD)

CPU manufacturer providing healthy competition for Intel. AMD chips such as the K6 or Athlon 64 and latterly the Ryzen have been very popular with computer manufacturers and have often out-performed their Intel equivalents.

Advanced RISC Machines (ARM)

Designer of CPU and chipset architectures widely used in mobile devices. RISC stands for Reduced Instruction Set Computing. RISC microarchitectures use a small number of simple instructions that can be performed as a single operation. This contrasts with complex (CISC) microarchitectures, which used a large set of more powerful instructions that can take more than one operation to complete.

multithreading

CPU architecture that exposes two or more logical processors to the OS, delivering performance benefits similar to multicore and multisocket to threaded applications.

multi-socket

Motherboard configuration with multiple CPU sockets. The CPUs installed must be identical.

multicore

CPU design that puts more than two cores into the same package.

support virtualization

CPU extensions to allow better performance when a host runs multiple guest operating systems or VMs.

AMD socket type

CPU socket form factor where connector pins are located on the CPU package.