Hardware
Computer hardware, electronics, chips, and physical computing
GPU (Graphics Processing Unit): From Rendering Pixels to Training AI
A GPU is a massively parallel processor originally designed for graphics rendering that has become the dominant hardware platform for AI training and inference.
SRAM vs DRAM: The Speed-Density Trade-Off Behind All Modern Memory
SRAM (Static RAM) uses six transistors per bit and holds data without refresh — fast but large and expensive. DRAM (Dynamic RAM) uses one transistor and one capacitor per bit — dense and cheap but requires constant refresh because capacitors leak charge. This fundamental trade-off is why CPUs use SRAM for caches (small, fast, expensive) and DRAM for main memory (large, slower, cheap). The DRAM refresh requirement creates the latency stalls that techniques like Tail Slayer are designed to mitigate.
SSDs: Solid-State Drives That Replaced Spinning Disks
SSDs store data in NAND flash memory with no moving parts, delivering dramatically faster performance than HDDs — connected via SATA (~550 MB/s) or NVMe/PCIe (3,500-7,000+ MB/s).
NAND Flash Memory: How Solid-State Storage Stores Data in Trapped Electrons
NAND flash stores data as electrical charge in floating-gate transistors, with SLC/MLC/TLC/QLC variants trading storage density against write endurance.
SATA: The Serial ATA Interface for Storage Devices
Serial ATA (SATA) is the standard interface for connecting storage devices (hard drives, SSDs, optical drives) to computers. It replaced Parallel ATA (PATA/IDE) starting in 2003. SATA III (2009) provides 6 Gbit/s bandwidth. The interface uses two separate connectors: a 7-pin data cable and a 15-pin power connector delivering 3.3V, 5V, and 12V. SATA is being superseded by NVMe for high-performance storage but remains dominant for bulk storage and optical drives.
NVMe: The Storage Protocol That Replaced SATA for High-Performance Drives
NVMe (Non-Volatile Memory Express) is a storage protocol designed specifically for flash-based SSDs, communicating directly over PCIe rather than through a SATA controller. NVMe drives achieve 3,500-7,000+ MB/s read speeds (vs SATA's ~550 MB/s limit), with dramatically lower latency and higher queue depth. Common form factors are M.2 (gumstick-sized, directly on the motherboard) and U.2 (enterprise, hot-swappable). NVMe has become the standard for primary storage in modern computers.
Modular PSU Cables Are Not Interchangeable: A Common Cause of Drive Death
Modular power supply cables from different manufacturers or even different models from the same brand are not interchangeable despite physically fitting. The device-side connector is standardized (SATA), but the PSU-side pinout is not — mixing cables can reverse polarity or apply wrong voltages, instantly destroying hard drives and SSDs.
LUTs: The Configurable Logic Blocks Inside FPGAs
Look-Up Tables are the fundamental building blocks of FPGAs — small SRAM blocks that can implement any boolean function by storing its truth table.
Pipelining: The Processor Technique That Keeps Every Stage Busy
Pipelining splits instruction execution into stages running simultaneously on different data, enabling one instruction to complete per clock cycle at peak throughput.
Surface Mount Technology: The PCB Assembly Method Behind All Modern Electronics
Surface mount technology is the dominant PCB assembly method, using automated pick-and-place machines and reflow soldering to mount components directly on the board surface.
Western Digital: From Semiconductor Startup to HDD/SSD Duopolist
Western Digital is one of two dominant storage manufacturers alongside Seagate, having acquired HGST and SanDisk to span both hard drives and flash storage.
BGA (Ball Grid Array): High-Density IC Packaging with Hidden Solder Joints
BGA is an IC packaging format using a grid of solder balls on the underside, enabling higher pin density than perimeter-pin designs but requiring X-ray inspection.
VHDL: The Hardware Description Language for Digital Circuit Design
VHDL is a strongly-typed, concurrent hardware description language used to design and simulate digital circuits for FPGAs and ASICs — more common in Europe and defense.
AHCI: The Storage Interface That Became a Bottleneck for SSDs
AHCI is the interface specification for SATA storage that replaced legacy IDE, but its single command queue and HDD-era design made it a bottleneck for fast SSDs.
Through-Hole Technology: The Original PCB Assembly Method
Through-hole technology inserts component leads through drilled holes in PCBs for wave soldering — older than SMT but still used for connectors and power components.
Hot Air Rework Station: The Essential Tool for SMD Soldering and PCB Repair
A hot air rework station uses a precisely controlled heated air stream to solder and desolder surface-mount components, essential for BGA and fine-pitch SMD work.
Surface Mount Devices (SMD): The Tiny Components on Modern Circuit Boards
Surface Mount Devices (SMDs) are electronic components designed to be soldered directly onto the surface of a PCB rather than through drilled holes. They are dramatically smaller than their through-hole predecessors, enabling the miniaturization of modern electronics. SMD soldering requires different techniques than through-hole work: solder paste and hot air reflow for production, or fine-tip irons and flux for hand work. Common SMD components include resistors, capacitors, diodes, and ICs in standardized package sizes.
HDD PCB Electrical Failure: TVS Diodes, Fuses, and DIY Repair
Hard drive PCBs have TVS diodes and zero-ohm fuses near the SATA power connector that form a sacrificial protection circuit. When an overvoltage event occurs, the TVS diode shorts to clamp voltage, then the fuse blows to cut current — leaving the drive appearing completely dead but often recoverable with basic soldering skills.
The Hard Drive PCB Swap Myth: Why It Fails and How ROM Transplants Work
Swapping a hard drive's PCB with one from an identical model almost never works on drives made after ~2003 because each PCB contains an 8-pin ROM chip with factory-calibrated adaptive data unique to that specific drive. Without transplanting the ROM chip, the mismatched parameters can crash the read/write heads into the platters.
Tail Slayer: Hedging DRAM Refresh Latency for Sub-Microsecond Reads
DRAM refresh stalls (~400ns every ~3.9μs) create unpredictable tail latency spikes. The 'Tail Slayer' technique duplicates data across memory channels and races reads on separate cores — whichever channel isn't mid-refresh wins. Achieves up to 15x P99.99 latency reduction on commodity hardware across Intel, AMD, and ARM platforms.
M1 Mac Mini: Adding More Than 2 External Displays
M1 Mac Mini supports max 2 native displays; add up to 3 more via Wavlink SiliconMotion dock (~110 EUR) over USB 3.2 Gen 2, best for static content only.