Storage Devices and Pwr Supplies (Chapter 2) Flashcards
What is the hard drive controller?
Chip that controls drive opertation. It also knows how sectors are laid out.
It’s the brains
Understand the layout of a hard drive platter
What is a sector on a hard drive?
smallest unit of storage
What does a host bus adapter do?
Translates signals from the HD controller to the computer
Located in the motherboard these days
What are the two most common form factors of HDDs?
3.5” (desktop)
2.5” (laptop)
Recall HDD speeds
5,400 rpm
7,200 rpm
10,000 rpm
12,000 rpm
15,000 rpm
How does SSD capacity compare to a HDD?
Generally smaller while being more expensive
What does “interface” refer to on an SSD?
What types does an SSD use?
The physical connection and the data transfer protocol.
NVMe: M.2 form factor, PCIe motherboard bus, NVMe protocol
SATA: M.2 form factor, SATA motherboard bus, SATA protocol
The M.2 slot on the mobo can use a PCIe or SATA bus
Is NVMe a type of connector?
No.
NVMe (non-volatile memory express) is the data transfer protocol.
M.2 is the form factor of the chip AND the form factor of the connector. The connector can use SATA or PCIe busses.
The motherboard must support NVMe as a boot drive
What is a communications interface and how does it differ from form factor?
Comms interface is how a device communicates with other components (SATA, PCIe, NVMe).
Form factor relates to the shape and size of the device (M.2, mSATA).
What are the two SSD form factors?
mSATA
M.2
(also 2.5” but not relevant for the test)
What is mSATA?
mini-Serial ATA
Small form factor for SSDs designed for small devices like ultrabooks and tablets
Uses a mini PCIe connector with SATA interface since its built on the same physical standard.
It was replaced by M.2
What is eSATA and why is it different from SATA?
External SATA
A difference in connector type and cable length is necessary for acommodating use outside the case (more durable, longer cable).
Recall that the M.2 form factor can use different interfaces/data transfer protocols (SATA NVMe).
mSATA is a form factor likely using a SATA interface
List the methods, benefits, fault tolerance and disk requirement of RAID 0
- Striping
- Improved read and write speeds
- No fault tolerance
- 2 disk minimum
List the methods, benefits, fault tolerance and disk requirement of RAID 1
- Mirroring
- Improved read speeds
- Fault tolerance through redundancy
- 2 disk minimum
Remember that this doubles the cost and reduces storage capacity by half
List the methods, benefits, fault tolerance and disk requirement of RAID 5
- Striping with parity
- Increased storage capacity
- Fault tolerance through parity
- 3 disk minimum
List the methods, benefits, fault tolerance and disk requirement of RAID 1+0
- Striping with mirroring
- Improved read speeds
- Fault tolerance through redundancy
- 4 disk minimum
How does a power supply handle current?
Converts 120V (US wall standard) or 220/240V (EU) AC into the DC voltage amount that the computer needs
What different voltages does a PSU supply?
12V, 5V, 3.3V DC
Newer motherboards have switched to 3.3 isntead of 5
Identify the two possible PCIe power connectors and related hardware
6pin or 8pin
Sometimes there are 6+2pins for modularity
GPUs
Identify SATA power and data connectors.
What is the purpose of a redundant power supply (RPS)?
If one fails, the other takes over without disruption.
Does not protect against power outages.
What is an uninterruptable power supply (UPS)?
A battery backup system that provides power redundancy (its literally just batteries)
What action does a UPS allow time for?
Safely powering down the system
How does a 20+4(24)-pin ATX connector compare to a 20-pin connector?
20-pin is unchanged, add a separate 4-pin connector to supply more current for higher power demands. A 20-pin connector can fit in a 24-pin mobo connector.
What’s a molex connector?
Old 4-pin power connector for peripherals (hard drives, fans, optical drives)
Molex/SATA adapters are common for use with PSUs that only have SATA power connectors.
Identify the CPU power connector
8 pin or 8 + 4 pin
+4 is used for overclocking
Where is CPU power plugged into the mobo?
What kind of current does hardware most often use?
DC
How is wattage calculated?
W = A * V
How can a power supply be switched to accept 220V (EU) instead of 120V (US)?
The toggle/switch on the back of the PSU
Some of them auto-switch
What electrical measurement has a postive or negative value?
Voltage
What happens to the current from the wall after it passes through the PSU?
Alternating current is converted into direct current (then split into different voltages)
What hardware is powered by 12V and which are powered by 3.3V?
12V: CPU, GPU, fans
3.3V: SSD, RAM
5V is less common
What is standby voltage?
+5V used for hibernation
Waits for you to press a button
In the US, what is the frequency of 120V AC from the wall?
60Hz
The current alternates at 60 times per second
What is the “power good” signal?
+5V signal from PSU that indicates power rails are stabilized within acceptable limits
Aids in startup process
What is the primary performance improvement of mirroring?
Faster read speeds
What benefit of RAID 5 stands out from other configs?
Increased usable storage capacity
What is the primary improvement of striping only (RAID 0)?
Both read and write is improved
because R/W operations are devided accross at least 2 disks
What file system does Windows use for internal drives?
NTFS
What are the two most common file systems used by Windows?
NTFS
FAT32
What is the maximum storage capacity of a single-layer DVD?
4.7 GB
What abilites does a DVD-ROM have?
Write once and never again
Good for archiving files
Which configuration would have the LEAST downtime if two drives were to fail?
RAID 5
RAID 1+0
RAID 10
Data remains available because it uses mirroring. RAID 5 parity would take longer to restore.
What file systems do Apple and Linux use?
Apple: HFS
Linux: EXT4
How much storage does RAID 5 eliminate?
33% with 3 disks
