Comprehensive PC Hardware & Cabling Study Notes

Sound Cards

Components and Conversion Chain

• Analog-to-Digital Converter (ADC)
  • Captures incoming analog sound waves and converts them into discrete digital samples.
• Digital Signal Processor (DSP)
  • Onboard processor that orchestrates both ADC and DAC operations and can add effects, mix channels, perform real-time compression, etc.
• Digital-to-Analog Converter (DAC)
  • Reconstructs analog waveforms from digital data so speakers/headphones can reproduce the sound.

Bus Support / Installation

• Sound cards can be:
  • Integrated on the motherboard (most modern boards)
  • Installed in an expansion slot: $\text{PCI}$ or $\text{PCIe\;x1}$ are the common options.
• Always match the card’s bus type with an available compatible slot on the motherboard.

Channel Configurations (Number of Discrete Audio Paths)

• 2-channel: Standard stereo (TV, radio).
• 4-channel: Quadraphonic (early surround-sound attempt).
• 5.1-channel: 6 total (Left, Right, Center, Left-Rear, Right-Rear, 1 LFE subwoofer).
• 7.1-channel: 8 total (adds Left-Side & Right-Side plus LFE sub).

Sampling Rate & Bit Depth

• Sampling rate = number of analog samples captured per second.
  • Telephone: $8\,\text{kHz}$ (voice requires (~4\,\text{kHz}) bandwidth).
  • Radio quality: $22\,\text{kHz}$.
  • CD quality: $44\,\text{kHz}$ (captures frequencies up to $20{,}500\,\text{Hz}$ – human hearing limit).
  • Digital TV / DVD: $48\,\text{kHz}$.
  • DVD-Audio: $96\,\text{kHz}$.
  • LPCM / Blu-ray: $192\,\text{kHz}$.
• Bit-depth (sampling size) – number of possible amplitude values per sample:
  • 8-bit ⇒ $256$ steps
  • 16-bit ⇒ $65{,}536$ steps
  • 20-bit ⇒ $1{,}048{,}576$ steps
  • 24-bit ⇒ $16{,}777{,}216$ steps
  • 32-bit ⇒ $4{,}294{,}967{,}296$ steps

Feature / Codec Support

• DirectSound 3D – Microsoft API for positional/surround effects.
• EAX (Environmental Audio Extensions) – adds realistic game audio cues.
• THX – Cinema-grade output certification.
• Dolby Digital – frequency shaping & compression for multi-channel quality.
• DTS Digital – optical reader + decoding for theater-quality output.
• SDDS – Sony Dynamic Digital Sound with error correction.
• MIDI – protocol that stores performance data, not waveforms; lets PC act as synthesizer.

I/O Ports

• Analog OUT
  • Speaker-out (amplified, level controlled by card)
  • Line-out (un-amplified feed to external amps)
• Analog IN
  • Line-in – accepts signals from external players/instruments.
  • Mic-in – pre-amp for microphones.
• Digital Audio
  • Internal CD/DVD digital header (direct playback without analog cable).
  • HD-audio pass-through header to GPU (combines audio + video for HDMI).
  • S/PDIF (optical or coax) for external digital devices.
• Extra
  • MIDI/Game port (legacy DB-15 on older cards)
  • Some high-end cards integrate HDMI I/O.

Common File Types Generated or Played

• WAV – Windows PCM standard.
• AIFF – Macintosh equivalent.
• AU – Unix/Web legacy.
• MP3 – MPEG-2 Layer III lossy compression.
• AAC – MPEG-2/MPEG-4 Advanced Audio Coding (successor to MP3).
• WMA – Microsoft competitor to RealAudio.
• MIDI – note & control data only (no sound waves).

Video & Capture Cards

Integrated vs. Dedicated GPUs

• Integrated (iGPU)
  • GPU built into CPU package or motherboard chipset.
  • Shares system RAM, low cost/power, limited performance; common in laptops, servers.
• Dedicated (dGPU)
  • Separate PCIe expansion card.
  • Own high-speed VRAM, higher cost, high performance, supports multi-card “daisy-chain” setups (SLI/CrossFire).

Installation Process (Dedicated Card)

1. Confirm motherboard slot type/availability (usually $\text{PCIe\;x16}$).
2. Disable integrated graphics in UEFI/CMOS if present.
3. Install primary card in first open x16 slot.
4. For multi-GPU:
   • Install identical secondary card in next x16 slot.
   • Bridge the cards (physical bridge or software, per vendor).
   • Attach auxiliary PCIe power connectors (6-pin/8-pin/12-pin) and any extra motherboard GPU power header.
5. Connect monitor to primary card.
6. Boot, install drivers & vendor control software (esp. for SLI/CrossFire profiles).

Core Characteristics When Selecting a GPU

• Display connectors: DisplayPort, HDMI, USB-C/VirtualLink, (legacy) DVI/VGA.
• Resolution & Refresh Rate capabilities
  • Card advertised by max resolution (e.g., $5120 \times 2880$) and refresh (75 Hz – 240 Hz+).
• GPU clock (MHz) – can be factory OC or user-overclocked (↑ performance, ↑ heat/watts).
• VRAM amount & type
  • DDR3/4/5 (cheap) vs. specialized GDDR2-GDDR6X (fast, expensive).
  • Typical 1 GB – 24 GB.
• Bus interface: PCIe x16 (modern), rare legacy AGP / PCI.
• Multi-GPU capability: NVIDIA SLI vs. AMD CrossFire (requires matching board & identical GPUs).
• HDMI audio support
  • Audio pass-through cable from motherboard audio header, OR
  • Onboard audio codec on GPU ("HDTV out").
• API Support
  • DirectX version (e.g., 12), OpenGL, Vulkan.
• HDCP compliance – required for protected Blu-ray/DVD playback chains.

Capture Cards

• Purpose: encode on-screen or console output for livestreaming/recording.
• Typical connections: HDMI → PCIe/USB-C/Thunderbolt capture.
• Required gear: source device, capture card, extra HDMI, display, encoding PC, capture software.

Adapters & Converters (Display/Data)

• HDMI ↔ DVI (digital only)
• VGA ↔ DVI (adds analog pins)
• VGA ↔ HDMI (requires active conversion for analog→digital)
• DVI ↔ Thunderbolt (via Mini DP/USB-C alt-mode)
• Ethernet (RJ-45) ↔ USB (USB NIC dongle)
• Always verify gender (male/female) & orientation when purchasing.

Storage-Cable Facts

Internal Interfaces

• SATA (Serial ATA)
  • 7-pin data + 15-pin power, up to $600\,\text{MB/s}$ (SATA 3.0). Cables ≤ 1 m.
• PATA / IDE
  • 40-pin ribbon, 18 in. max, uses Molex #8981 4-pin power.
• SCSI Parallel Interface (SPI)
  • 50/68/80-pin ribbon, up to $640\,\text{MB/s}$.
• SAS (Serial Attached SCSI)
  • Point-to-point serial, SFF connectors, hot-swappable, SAS-4 $22.5\,\text{Gbps}$ duplex.
• Molex (generic 4-pin power connector) – legacy disk power.

External Storage Cables

• eSATA – external hot-swap SATA.
• External SCSI – shielded 68-pin cables, daisy-chain up to 7/15 devices (terminate last).
• iSCSI – SCSI over TCP/IP (up to $400\,\text{MB/s}$), long distance via existing network.
• Fibre Channel – duplex fiber with SFP transceivers, $200\,\text{MB/s}$+.

Peripheral & Video Cables Overview

Modern Video

• DisplayPort (DP)
  • Multiple streams, up to $8194\times4320$, 20-pin locking, Mini-DP variant.
• HDMI (Types A – D)
  • Carries video + 8-channel audio, up to 25 ft before booster.

Older Video

• DVI (A/D/I, single vs. dual-link) – up to $2560\times1600$.
• VGA DE-15 – analog only, $640\times480$ baseline.

Other Ports

• S/PDIF (coax or optical) – digital audio.
• Audio jacks (3.5 mm TRS): green = line-out, pink = mic-in, blue = line-in, orange = sub, black = rear.
• PS/2 (Mini-DIN-6) – legacy keyboard/mouse (purple/green).
• Serial DB-9 (RS-232), Parallel DB-25.
• RJ-45 (Ethernet), RJ-11 (phone).
• Apple: Thunderbolt 3 (USB-C w/ lightning icon, 40 Gbps); Lightning (mobile iOS devices).

Expansion Bus Types

• PCI (parallel)
  • 33 MHz/133 MBps or 66 MHz/266 MBps, plug-and-play.
• PCIe (serial, point-to-point)
  • Lane widths: x1, x4, x8, x16, x32.
  • Bandwidth per lane per direction:
  • v1.0 $250\,\text{MBps}$
  • v2.0 $500\,\text{MBps}$
  • v3.0 $1\,\text{GBps}$
  • v4.0 $2\,\text{GBps}$
  • Cross-size compatibility: smaller card fits larger slot (not vice-versa).
• Legacy: AGP (video), AMR, CNR risers.

USB Essentials

Core Features

• Serial, plug-and-play, hot-swappable, cross-platform.
• Supplies power: up to $5\,\text{V}$ legacy, $20\,\text{V}$ via USB-C PD.
• Supports up to $127$ devices per host; hubs limited to 5 daisy-chain tiers.

Standards & Speeds

• USB 1.0 (Low Speed) $1.5\,\text{Mbps}$
• USB 1.1 (Full Speed) $12\,\text{Mbps}$
• USB 2.0 (Hi-Speed) $480\,\text{Mbps}$
• USB 3.2 Gen 1 (USB 3.0/3.1 G1) $5\,\text{Gbps}$
• USB 3.2 Gen 2 (USB 3.1 G2) $10\,\text{Gbps}$
• USB 3.2 Gen 2×2 $20\,\text{Gbps}$
• USB4 Gen 2×2 $20\,\text{Gbps}$, USB4 Gen 3×2 $40\,\text{Gbps}$

Cable Length Limits (direct)

• USB 1.1 ≤ 3 m; USB 2.0 ≤ 5 m; USB 3.x ≤ 3 m; USB4 ≈ 0.8 m (passive).

Connector Types

• USB-A (standard host, blue tab = 3.x)
• USB-B (square, printers/external drives)
• Mini-B (legacy cameras) → replaced by Micro-B (phones/tablets)
• USB-C: reversible, symmetric, 10k insertion cycles, supports data/video/power (PD) and alt-modes (DP, Thunderbolt).

Power Classification

• Bus-powered: low (≤ 100 mA) or high (100–500 mA; 900 mA for 3.0)
• Self-powered: own AC adapter (mandatory if > 500/900 mA)
• Hubs can be bus- or self-powered; high-draw devices must not attach to bus-powered hub.

Installation Hint

• Install driver first, then plug device (older Windows guidance).

Network Cabling

Twisted-Pair (TP)

• Components: 4 pairs copper, PVC insulation, overall sheath; UTP (no shield) vs. STP (foil/braid shield).
• Advantages: cheap, flexible; Disadvantages: EMI-susceptible, eavesdropping, limited bandwidth.
• Categories & Specs (UTP RJ-45 unless noted)
  • Phone cable (2 pairs, RJ-11) – dial-up.
  • Cat 5 $100\,\text{Mbps}$, $100\,\text{MHz}$.
  • Cat 5e $1\,\text{Gbps}$, better EMI.
  • Cat 6 $10\,\text{Gbps}$ ≤ 55 m, $250\,\text{MHz}$.
  • Cat 6a $10\,\text{Gbps}$ 100 m, $500\,\text{MHz}$, extra shield.
  • Cat 7 $10\,\text{Gbps}$, $600\,\text{MHz}$ shield only.
  • Cat 7a $10\,\text{Gbps}$, $1000\,\text{MHz}$.
  • Cat 8.1 (25 Gbps) / 8.2 (40 Gbps), $2000\,\text{MHz}$, shield only, non-backward connectors (class I/II).
• RJ-45 pinouts
  • Patch (straight-through): both ends T568A or T568B.
  • Crossover: one end A, other B.
  • Cat 5 (100BASE-T) pins: 1-Tx+, 2-Tx-, 3-Rx+, 6-Rx-.
  • Cat 5e+ (1000BASE-T) pins use all four pairs bidirectionally.
• Tools/Best Practices: RJ-45 crimpers, punch-down blocks, maintain twists to connector, prefer pre-made Cat 6 due to strict spec.
• Environmental ratings
  • Plenum (low-smoke), Riser (vertical shafts), Direct-Burial, General-purpose.

Fiber-Optic

• Construction: core (glass), cladding, protective layer, outer sheath.
• Advantages: immune to EMI, secure, long distance, highest speed.
• Disadvantages: cost, fragile, requires specialized training.
• Modes
  • Single-mode: ~10 µm core, single light ray, longest distance, highest bandwidth.
  • Multi-mode: 50–100 µm core, multiple rays, shorter range.
• Common Connectors
  • ST (twist/bayonet), SC (push-pull w/ tab), LC (small RJ-style), MT-RJ (duplex in one block).

Coaxial

• Layers: copper core, PVC insulator, braided shield, outer PVC sheath.
• Grades
  • RG-59: CCTV, short runs (< 3 m), 75 Ω.
  • RG-6: Cable/Sat/Modem internet, 75 Ω, lower loss.
• Connectors
  • BNC (bayonet) – legacy 10Base2 & pro video.
  • F-Type (threaded) – cable TV/modem; crimp or twist-on (twist risk leakage).

Environmental & Maintenance Considerations

HVAC Guidelines for IT Spaces

• Temperature: $70{-}74^{\circ}\text{F}$ (≈ $21{-}23^{\circ}\text{C}$).
• Humidity: $40{-}70\%$ to mitigate ESD.
• Use separate or dedicated HVAC ducts for server rooms; positive pressure preferred (forces air out, blocks dust/smoke).
• Add intake filters in dusty/smoky environments.

Interference & Magnetic Fields

• EMI: motors, fluorescent lights; mitigate with STP cabling or fiber.
• RFI: 2.4 GHz Wi-Fi vulnerable to cordless phones/microwave; switch channel or move to 5 GHz.
• Magnetic fields: strong magnets near HDDs can erase data; SSDs unaffected. Keep disks away from speakers, motors.

Cleaning Best Practices

• Supplies: lint-free cloth, compressed air, anti-static vacuum, natural-bristle brush, isopropyl/denatured alcohol.
• Always power-down & unplug; let cool 30 min.
• Blow or vacuum dust; alcohol on cotton swab for contacts.
• LCDs: dry lint-free cloth or isopropyl; avoid ammonia/window cleaner.
• Keyboards: compressed air; swab sticky keys.
• Printers: inkjet self-clean; laser – anti-static vacuum toner.
• Newly shipped PC: acclimate ≥ 6 h (24 h if previously frozen) before power-up.
• Organize & route cables; ensure fans oriented for proper airflow.
• Perform scheduled data backups.