timestretching depends on hardware?

Hi,
i have Cross DJ running on my Android and changing the tempo with the slieder does not change the key, which is great. On my tablet (512MB, single core) it does change it. Did i miss something or is timestretching dependend on the device's performance?
i have Cross DJ running on my Android and changing the tempo with the slieder does not change the key, which is great. On my tablet (512MB, single core) it does change it. Did i miss something or is timestretching dependend on the device's performance?