Unlocking PSP's future

The general perception of PSP games right now is that they look pretty good. Pretty damn good. You probably wouldn't be surprised if I told you that PSP games are going to look considerably better in the future. It stands to reason that over time, games look better and better across a console's lifespan as developers become more accustomed to the hardware and learn to exploit it more effectively. The first-generation games might put just as much strain on the system as the late-generation games, but the tangible improvements come from much more efficient coding. The console's capabilities don't improve, only the software does. Such is the case with all consoles.

What if I told you that PSP was different? What if I told you that as well as enjoying the benefits of steadily improving software development, the PSP would, at some stage in the future (and without any modification), become capable of a hardware performance increase of fifty percent? That would be somewhat more surprising, wouldn't it?

Well, that's what I'm telling you. At this year's busy GDC (Game Developers Conference) in San Francisco, lots of companies gave lots of presentations. On Friday the 11th of March, between midday and 1pm, Sony Computer Entertainment America staged four different presentations simultaneously. Mark DeLoura, SCEA's manager of developer relations, delivered one of them: a rather dry and technical presentation called "PSP Advanced Software Overview". It seems that with so many talks vying for attention, this particular presentation may have slipped under the radar of the mainstream gaming press. What was revealed in that presentation however, is very significant.

DeLoura explained that the PSP's CPU and bus have software-configurable clockspeeds. The CPU core is currently locked to a maximum clockspeed of 222MHz, and the bus (typically operating at half the CPU speed) is locked to a top speed of 111Mhz. The GPU (Graphics Processing Unit) operates at bus speed, in other words, up to the 111MHz cap. The advantage of having configurable clockspeeds in a portable device is that power consumption can be controlled by adjusting the clockspeed to the demands of the software at any given moment. When the PSP is rendering complex in-game graphics at around 222MHz it will necessarily chew up more power than it would need to when displaying a simple menu screen running at say 5MHz.

The hardware specifications of the PSP were released last year. Since then it's been known that the PSP CPU's top clockspeed is 333MHz and the bus and GPU's top speed is 166MHz. See what's going on? Sony have deliberately locked the PSP's operating speed at exactly two-thirds of it's actual potential. They have an extra fifty percent of it's current performance ability simply waiting in reserve to be unleashed at a later date.

As I pointed out in my PSP Lowdown back in January, the graphical performance exhibited in PSP's launch titles looks like it's somewhere between PSone and PS2 standard. Now I understand why. The PS2's Emotion Engine (CPU) runs at 294.912MHz and it's Graphics Synthesizer (GPU) runs at 147.456MHz. While the PSP is clearly a more powerful device on paper, it's currently being restricted to a sub-PS2 standard of performance.

Of course, this begs the question: why? Why would Sony choose to cripple their own hardware? Well, the most obvious answer is that they needed to maintain an acceptable battery life. In the lead up to PSP's debut, it's battery duration was often quoted as it's single biggest potential problem. Had they launched the PSP with games running at a fully unlocked 333Mhz, the battery could have been dead in less than two hours. That just wouldn't do. Through capping the PSP's clockspeed (and enforcing other power-saving guidelines) Sony have achieved a respectable 4-6 hours of gameplay from a single charge. It now seems apparent that Sony have actually delivered a portable console whose capabilities are too advanced for current battery technology. Once that technology improves, it seems inevitable that Sony will release a higher capacity battery and unlock PSP's full potential.

The current performance cap may have other benefits in the long run. Rather than letting developers wastefully chew up the whole of PSP's hardware capability from the get-go with inefficient code, the restrictions essentially force them to code more efficiently from the beginning. Consequently, when the ceiling is eventually lifted, the developers will be ready to put the extra power to good use.

It has been theorized that the clockspeed cap is in the PSP's firmware, and will be removed by a firmware update. A developer at the gaming-age forums recently disclosed that this isn't the case. The restriction is actually being imposed at the game development stage, by way of limits in Sony's PSP libraries. The PSP devkits allow developers to constantly modify the CPU clockspeed settings from anywhere between 1 and 333MHz (or 0.5-166Mhz for the GPU and bus), but the current software libraries simply won't go above 222MHz (or 111Mhz for GPU and bus).

Initially restricting certain features of a console is not as uncommon as you might expect. As an example, the PS2 was restricted from displaying progressive scan for many years, though usually such restrictions are handled by the TRC process, not by a software restriction. The TRC (Technical Requirement Check) is the console manufacturer's checklist that games must pass before being published. Any developers who try to hack the current PSP libraries to exceed the clockspeed limits will undoubtedly have their games rejected at the TRC stage. Sony probably felt it would be easier to simply restrict the libraries than to ask the developers politely not to go above 222Mhz, and have to later issue a wave of TRC rejections. Sony will provide developers with new software libraries when they are ready to remove the restrictions. Games developed after that will be free to exploit all of the PSP's processing power. Ridge Racers' associate producer Hideo Teramoto recently confirmed in an Edge magazine interview that unlike the underclocked Ridge Racers, Namco will release PSP games in future that run at 333MHz.

When the time comes, consumers won't need to do anything. No firmware update should be required. Old games won't run any faster than they ever did, because the restrictions are in the game software, not in the PSP itself. The new games will simply push PSPs harder than ever before. Sony will have much improved high-capacity batteries on the market by then, but you won't actually need to buy one. The latest and greatest games will run on your old battery. Of course, the speed at which they'll drain your old battery should be incentive enough for you to rush out and buy a new one.

The tangible difference in the games should be very noticeable. Example: Right now, the PSP has a maximum fillrate of 444 Mpixels/sec. After the restrictions are lifted that will become 664 Mpixels/sec. Games will be able to feature more complex models with higher polygon-counts, more fluid frame-rates, better physics, you name it. We are talking about an across-the-board fifty percent performance increase after all. PSP's hardware supremacy over the PS2 should become evident. It's even possible that when the new battery is released, the PSP's fourth screen brightness setting (uber-blinding strength; currently only selectable when the PSP is plugged into mains power), will be available all the time.
PSP's future certainly looks bright.