Under the minimum specs for Macs on all sites including Steam list a ATI Radeon HD 6750 with 1gb VRAM. The recommended specs show AMD R9 390M that indicates they are going by iMac specs. However, if they are going by iMac specs the Radeon HD 6750M that came stock with older iMacs only had 512mbs of VRAM. I am asking this because I am trying to figure out if someone I know who has a late 2009 i7 iMac with 8gb of RAM and a Radeon HD 4850M which according to sites like GPUBoss beat the 6750M can handle Stellaris at mimum settings? As both can support OpenGL 2.x and a little up are there any issues with these specs?
GPUBoss Link: http://gpuboss.com/gpus/Radeon-HD-6750M-Mac-vs-Mobility-Radeon-HD-4850-Mac
GPUBoss Link: http://gpuboss.com/gpus/Radeon-HD-6750M-Mac-vs-Mobility-Radeon-HD-4850-Mac