PlayStation 4.5 is "real", with prototype devices available in Sony's Research and Development labs, Digital Foundry claims to have confirmed via numerous independent sources.
Its sources also seem keen to refer to the new system as PlayStation 4K, so this could be a more likely name for the console.
So what of its capabilities? Digital Foundry states that whilst some significant performance improvements could be offered over existing hardware, hitting a spec capable of delivering 4K games with the richness we see now in 1080p is a pipe dream.
"Everything we've heard positions PlayStation 4K as a machine capable of playing current and next-generation ultra HD media, while also offering support for other aspects of the 4K spec, such as high-dynamic range and a wider colour gamut - aspects of the 4K spec that could be introduced to gaming," explains DF's Richard Leadbetter. "However, in terms of additional computational power, we've got be realistic about what Sony can deliver with a mid-generation refresh."
Digital Foundry theorises three possible hardware specs for PS4K, ranging from a more expensive system capable of delivering around twice the performance of PS4, to something only marginally more capable than the existing hardware, but in a smaller form factor and with full support for 4K standards.
A speculative 2017 release date is also mentioned several times.
Source: Digital Foundry