HAP trades low CPU usage for high storage bandwidth, so full-quality playback needs a fast drive (SSD)

HAP’s GPU-decompression approach dramatically reduces CPU load (Vidvox measure roughly 10% versus 26% for Photo-JPEG and 34% for Apple Intermediate Codec), but GPU-native texture formats compress far less efficiently than CPU codecs, so data-rates are high: Vidvox quote about 134 Mbit/s for plain Hap and 280 Mbit/s for Hap Q. This means the storage system must deliver enough sustained read bandwidth for all simultaneous streams. Vidvox therefore state you need a fast drive, preferably an SSD, to benefit from Hap — a spinning HDD may not sustain the read speed for several simultaneous Hap Q streams. The practical takeaway: HAP moves the bottleneck off the CPU and onto disk throughput, so variant choice (Hap vs. Hap Q) must be weighed against your drive’s capability.

Examples

Four simultaneous 1080p Hap Q streams at ~280 Mbit/s each is ~140 MB/s of read bandwidth. A fast SSD (500+ MB/s) handles this comfortably; a spinning HDD (100-150 MB/s) will drop frames.

Assessment

Explain why HAP shifts the playback bottleneck from CPU to storage, cite the approximate CPU-load advantage over Photo-JPEG, and state what drive type Vidvox recommend and why.