| Game Title | Raw GDI Size | Highly Compressed (CHD) Size | Savings | | :--- | :--- | :--- | :--- | | | 850 MB | 210 MB | 75% | | Jet Set Radio | 780 MB | 190 MB | 75% | | SoulCalibur | 1.1 GB | 450 MB | 59% | | Power Stone 2 | 960 MB | 380 MB | 60% | | Marvel vs. Capcom 2 | 680 MB | 220 MB | 67% | | Skies of Arcadia | 1.2 GB | 610 MB | 49% | | Hydro Thunder | 550 MB | 120 MB | 78% | | Virtua Tennis | 480 MB | 90 MB | 81% | | Resident Evil: Code Veronica | 1.0 GB | 520 MB | 48% | | Ikaruga | 320 MB | 95 MB | 70% | Performance Impact: Does Compression Kill the Dream? The golden rule of emulation: CHD compression introduces virtually zero CPU overhead. Modern processors (even on a Raspberry Pi 4 or a mid-range Android phone) can decompress CHD on-the-fly faster than a real Dreamcast’s GD-ROM drive could read data.
In contrast, older compression uses weaker algorithms and fragmented audio tracks, which can cause stuttering in games like Shenmue 's QTE sequences or Sonic Adventure 2 's cutscenes.
However, for those diving into Dreamcast emulation today (via , Flycast , or nullDC ), there is one persistent problem: Storage space .