Videokabely (DVI, HDMI)

Video cables carry video signals (and often audio) between a source device such as a graphics card, laptop, or Blu-ray player, and a display like a monitor or TV. Choosing the right cable comes down to matching bandwidth, connector type, and signal compatibility to your application. HDMI (High-Definition Multimedia Interface) is the most widely used standard, combining uncompressed digital video and audio in a single cable. Its categories generally map to performance when paired with compatible devices and certified cables: Standard (≈4.95 Gbps) supports basic HD, High Speed (10.2 Gbps) supports 1080p and limited 4K formats, Premium High Speed (18 Gbps) supports full 4K at 60 Hz including HDR in most configurations, and Ultra High Speed (48 Gbps) enables 4K at 120 Hz, 8K, HDR, and advanced gaming features. In practical terms, full-bandwidth 4K/60 (including 4:4:4 chroma and HDR) typically requires Premium High Speed HDMI, while 4K/120 requires Ultra High Speed. Most issues such as black screens at higher refresh rates, flickering, or missing HDR, stem from insufficient cable bandwidth, unsupported device ports, or chroma/subsampling limitations rather than cable “quality.” DisplayPort and USB-C (with DisplayPort Alt Mode) are also common, especially in PCs and docking setups, but require confirmation that the port supports video output and that any adapter preserves the intended signal type and bandwidth.

DVI (Digital Visual Interface) remains relevant in legacy and industrial systems but requires careful selection due to multiple variants: DVI-D (digital), DVI-A (analog), and DVI-I (integrated). It also supports Single Link (up to 1920×1200) and Dual Link (for higher resolutions like 2560×1600 or high-refresh 1080p). Compatibility issues are common: DVI is not the same as VGA (which is fully analog), and adapters only work when signal types align (e.g., HDMI to DVI-D works for digital video, but VGA to DVI-D does not). Cable length also plays a critical role as bandwidth increases, while short runs typically work without issue, longer cables can introduce signal degradation, especially at higher resolutions and refresh rates, leading to flickering, sparkles, or intermittent signal loss, sometimes requiring active cables or signal boosters. To avoid problems, focus on matching bandwidth to resolution and refresh rate, verifying connector compatibility on both ends, and using certified cables (such as Premium High Speed or Ultra High Speed HDMI) when pushing higher data rates.