Bit Tech writes many user complain about performance issues with Assassin's Creed: Unity. Ubisoft claims the issues are related to select AMD CPU and GPU combinations, which points to a lack of testing on AMD hardware. Then again, there are a lot of non-AMD gamers who complain about issues as well so it seems this is just another bad console port.
The reason for these problems, according to Ubisoft itself? An apparent lack of testing on diverse AMD hardware. 'We are aware that the graphics performance of Assassin’s Creed Unity on PC may be adversely affected by certain AMD CPU and GPU configurations,' the company wrote in a statement on the game's forum. 'This should not affect the vast majority of PC players, but rest assured that AMD and Ubisoft are continuing to work together closely to resolve the issue, and will provide more information as soon as it is available.'
At this point, it may be worth mentioning that Ubisoft partnered with Nvidia on the development of the title. As a flagship entry in the latter company's GameWorks programme, Asassin's Creed Unity features numerous enhancements which are active only on Nvidia graphics hardware - and, as a result, is likely to have received considerably more testing on Nvidia GPUs than on those from rival AMD.