PS3 To Run At 120 FPS?
Gamespot is running an article in which crazy man Ken Kutaragi boasts that the PS3 may be capable of running games at 120 fps. From the article: "Never mind that even newer TVs aren't capable of refreshing the screen 120 times in a single second. Kutaragi said that when new technology comes to market, he hopes to have the PS3 ready to take advantage of it. As for the Cell chip at the heart of the PS3, Kutaragi also had high hopes for its future beyond gaming. Using high-definition TV as an example, he said that the Cell chip could take advantage of the technology in many ways, such as displaying newspapers in their actual size, showing multiple high-definition channels on the screen at once, and video conferencing. He emphasized that the Cell can be used to decode more than 10 HDTV channels simultaneously, and it can also be used to apply effects such as rotating and zooming."
Who would have thought that the PS3 or any computer for that matter would be capable of refreshing _ANYTHING_ 120 times per second? Oh wait, the PS2 could, given its astounding fill rate and 70+ million polygon per second capacity. Well, I suppose that any computer with a sufficiently fast RAMDAC (circa 1994) could update a scene that quickly. Shucks, since no perspective is provided on the scene complexity, there is no doubt that a Matrox Mystique 220 could draw a single polygon at 120 FPS.
Kutaragi will always promise the Nile. It is his job. In this case, he offered absolutely nothing.
"My God, this must be a truly remarkable corn chip, to be so widely and confidently touted."
Of course the PS3 can do 120fps, any console can if it can output the signal (say, VGA on X360/DC). No games will ever run at 120fps, they will target 60fps, or 30fps, and they will base all their performance decisions around that number. Why do hardly any xbox games support 720p? Because it takes way more fill rate to draw that huge framebuffer, and they'd rather use those pixels to make the game look better on the majority of user's displays.
Why do I get the feeling that Sony wants to bring the 'fun' of configuring PC games to their console. I can just see it now, do you want to run fast at 480p, or more slowly at 1080i? How about some antialiasing to slow it down a bit more? I even seem to remember them saying something to that effect back around E3. What is the point of a fixed gaming platform if it's going to turn into that mess?
If you are running a game at only 60 fps on a display of 60Hz, you might not get anywhere near that frame rate. Since the image is generally only updated during vertical retrace (the longest moment when a scanline is not actively being drawn), you effectively have a window into which you have to fit your image. If you miss that window, the same frame is going to get drawn on the display again. Of course, TV signal is different from SVGA signal, and should be a continuous stream including the big black bar where the vertical retrace is supposed to happen (but you can see it when your vsync is off). But that just pushes the timing issue back to a chip inside the playstation, it doesn't eliminate it.
So, anyway, if you're running an -average- of 60 fps but you're actually running 59 fps alternating with 61 fps at -just- the right rate, you can manage to miss the window every other frame with just a very little bit of jitter for a worst-case scenario of 30 fps viewable even though you're rendering 60 fps avg internally. (Most of the time, of course, you won't have a worst case scenario, but OTOH, if you're that close to the line you're likely to have bad synchronization scenarios causing significant frame loss from time time.) At 120 fps rendered, you'd have to have a single frame take double the average time to cause a miss, a much less likely case. In most cases, you'll have two new frames ready to go in time for your deadline.
OTOH, they -do- have effective control of every video buffer, unlike the SVGA case where the deadline lives in the monitor. So in the computer case excessive frame-rate may be the only way to get your viewed frames to match the monitor's refresh speed, but there should be a cleverer solution in the console+tv case.
--Parity
'Card carrying' member of the EFF.