You may have seen that the PS4 moved a bit more than 12k units in the last Japanese sales update. This pushes the system across the 1.5 million mark for units sold in gaming’s motherland.

It achieves this some 15 months post-release, making the math quite easy: it’s been averaging around 100k systems sold per month. Sony’s challenge now, of course, will be to keep the numbers above that line, which can prove difficult, for a system so young, with its launch week becoming a distant memory. Well over a year later, launch weekend still accounts for more than 20% of all PS4s sold in the country.

PS4’s 1.5 million mark moves it ahead of Sega’s ill-fated Dreamcast for launch-aligned sales (meaning sales for the same number of weeks after each system’s respective launch). Until recently, Sega’s final console had maintained a higher pace than the PS4.

So how does that compare to other consoles whose sales are often brought into question? In the same time frame, PS3 was at about two million sold in Japan. Nintendo’s GameCube was near 1.9 million, and the Wii-U was sitting at 1.65 million.

The numbers are interesting, however, because the PS3 currently sits at about 10.3 million units sold in its lifetime, meaning the monthly average isn’t too far off from PS4’s. It had a weaker launch, but stronger longevity in the months and years that followed. So the PS4 currently sits about half a million behind the PS3 for its first-15-month sales numbers, yet its lifetime monthly average isn’t far behind. Keep an eye on that.

While these numbers show that the new consoles are lagging well behind their elders, none quite so much as the Xbox One. Since its September 2014 launch, the system has barely crested 52k systems sold in Japan. Its older brother the Xbox 360 sold more than 62,000 units in its launch week alone. That means that in about 10 months, the X1 has sold well under half of what the first Xbox sold in its opening week. Talk about a dropoff.