When rumours broke last week that the next generation Xbox would dump the disc drive, many scoffed. Among those who didn't is Epic CEO Tim Sweeney, custodian of the industry-leading Unreal Engine business. Sweeney feels an Xbox 720 that exclusively utilises solid state game storage would roundly trounce an Xbox 720 that sticks to discs - providing, that is, Microsoft can swallow the costs.

"You see that spinning optical media has about 250 milliseconds of latency," he toldGamesIndustry International at GDC. "If you want to get some bits from somewhere else on the disc, you have to wait a quarter of a second for the little mechanical elements to move the head around so they can read it.

"A hard-disc is about 20 times faster than that, and a solid state drive is tens of thousands of times faster. It's basically the speed of electrons that limits the solid state drive."

Lower latency allows game engines to handle larger environments more elegantly. "One of the major things a game needs to do in a world with a large environment and lots of graphical resources is continually go out and pull new textures and sounds and 3D models from different places in the storage media. So solid state drives have a really dramatic advantage from that point of view.

"It would certainly be desirable for the working storage to be solid state or some other extremely fast medium," he concluded. "But that's a completely separate question from distribution media. Solid state drive costs are fairly expensive."

A solid state machine would need to accompany a robust downloadable gaming service, as shipping games on solid state drives would be "terribly prohibitive economically". Microsoft might also retain discs but enforce installs to an internal solid state drive.

"There are lots of ways to get a game onto optimal media for playing the game," Sweeney explained. "If you look at decoupling the distribution media, whether it's internet or storage from the streaming medium (which is used during gameplay), you see far more flexibility than just in current console games. If all you have is a spinning drive, you just have to go out, load a resource, and wait for a drive to go out and do its mechanical work."

Wondering where you've heard the name "Sweeney" before? Well, there's this opera about a barber and some pies. Also, Sweeney thinks Xbox 720 needs to be at least three times as powerful as Xbox 360. For more (yet more!) in that vein, check out http://www.oxm.co.uk/35017/features/xbox-360-2-what-epic-wants/">our feature on what Epic wants from Microsoft's next console.