Sony recently revised the PS4 hardware, sneaking out a new model that was less power hungry, quieter and cooler - but it seems the new hardware hasn't been used on PS4s that are now being sold with a 1TB hard drive.
Our pals at TechRadar have issued a stark warning not to buy the 1TB version of the console if you're planning to buy a PS4 - and urging you to pick up the 500GB version instead.
The reason is because the 500GB version on shelves is the "CUH-1200" version of the hardware - which is 36% more power efficient when in rest mode and will use 25% less power when operating, whereas the 1TB version is the old model, "CUH-1100", just with a bigger disk slapped inside.
The new version of the hardware also has a smaller motherboard and a redesigned Blu-Ray drive.
The upshot, TechRadar argues, is that if you opt for the larger console you'll end up paying a tonne more on energy bills over the lifetime of your console.
If you want to check which version of the hardware you have, check this sticker on your console:
The expectation is that over the longer term (by Christmas?) when Sony has run down the stock of old PS4 hardware, the 1TB version will also make the leap to new - though as TechRadar suggests, if you're buying a PS4 any time soon then you might want to think about whether you really need that extra space. [TechRadar]