Imagination has declined to confirm the design win although detective work by members of the Beyond 3D Forum has revealed references to MBX in Apple iPhone firmware.

The originator of the "PowerVR MBX in iPhone" discussion thread at the forum referred readers to a flash memory firmware dump on an iPhone developers' Wiki site called iPhone Dev Wiki.

The original evidence was some references to a device type identified as 0x78626D. 0x78626D happens to be xbm, which is mbx backwards, the writer asserted. However another contributor to the forum pointed out that the MBX libraries are referred to in crash logs also listed at the same iPhone site.

Soon other forum members were finding references to graphics-related MBX device strings in cache dumps from the iPhone, including text strings such as "AppleMBXDevice(%p): Graphics hang with pending 2D blit." Some members of the forum appeared unfamiliar with Imagination or the PowerVR MBX core, wondering whether it was a stand-alone chip or included in the system chip.