https://bugs.winehq.org/show_bug.cgi?id=46225
--- Comment #29 from Bryan Kirk Zero3K@teknik.io --- 1. I am seeing near 100% CPU usage when running it in ReactOS which is using WINE's code for the drawing of GDI based programs. When running it in Windows 7, it is only using 16-25% of my CPU.
2. I think that they both are using GDI to draw the gameplay (if not Melty Blood, then definitely Iconoclasts since Steam doesn't need to install DirectX for it to run properly).