Harrison has defended the inclusion of Blu-ray in the PlayStation 3. It's a decision that has not only contributed to the PS3's high launch price ($600), but has delayed the Sony console's European launch into 2007 due to a lack of blue laser diodes for the drives. Blu-ray is crucial to Sony's next-generation strategy, but Harrison claims that it's not just for high-definition movie playback.
"DVD is not sufficient", he says. "We need Blu-ray to supply the kind of data that PS3 games use."
Does disc size really matter?
What kind of 'data' is Harrison talking about? Think 7.1 surround, high-resolution textures and more detailed character models - with a 25GB Blu-ray disc, PlayStation 3 developers have access to over three times the storage capacity of the DVD-9 disc used by Microsoft's Xbox 360.
Yet the first batch of PlayStation 3 launch titles, such as Resistance: Fall of Man (pictured) and Ridge Racer 7 don't seem to demonstrate a dramatic leap in quality over this year's leading Xbox 360 titles.
"Sony has announced that Resistance already requires more than 22GB of storage," says Margaret Robertson, editor of Edge magazine. "But the pre-release version Sony was able to show at the Tokyo Game Show didn't offer a clear visual advantage over the Xbox 360's Gears Of War."
There's a danger here that the extra storage capacity offered by Blu-ray will be filled up with 1080p textures that few people can actually display on their TVs; or games will be padded with non-interactive video sequences that look pretty but add nothing to the gameplay. If developers can't effectively use the single-layer 25GB Blu-ray discs, what will they do with the dual-layer 50GB ones that will be available next year?
Quantity or quality?
"Filling 25GB isn't necessarily that impressive," adds Robertson, "especially if it includes all the international voicing and nothing is compressed. The big question is how much quality you actually lose to fit the same game on DVD. As things stand at the moment, it doesn't seem to be a great deal. What's less clear is how much quantity you may lose - so although Resistance doesn't outshine Gears Of War visually, we don't know yet if it's going to be a much larger game, with more varied environments.
"Three years down the line, when everything really is being made in 1080p, then studios might be relying on Blu-ray. But so far no developer we've spoken to has singled out disc space as a particular advantage of PS3".
Looking to the future, optical storage may well become irrelevant as the home entertainment industry flirts with the idea of digital delivery.
As broadband speeds have improved, corporations like Apple have moved from music to video downloads. The landmark deal to download episodes of Lost was just a precursor to the current availability of full-length movies like The Incredibles and Pirates of the Caribbean on iTunes.
The gaming industry is arguably ahead of the curve here - Valve's Steam service is already offering the sort of click-and-buy digital downloads that should make high street retailers nervous.
"It's not hard to imagine that as soon as the broadband infrastructure supports fast full game downloads, Microsoft will be right there and ready to deliver," says Steve Brown, editor of the UK's Official Xbox 360 magazine . It'll make Sony's 'I've got a bigger disc than you' swagger even more irrelevant."
"Everything we have seen of Xbox 360's second age of next-generation games (Gears of War, Halo 3, Bioshock, Splinter Cell and more) suggests that visually, and in terms of content, there isn't a single PS3 launch game that can equal Xbox 360's exclusives in quality. Blu-ray is not about better games. It's about selling an unproven movie format that Sony has invested in up to the hilt."
Edge has an exclusive interview with Sony's Phil Harrison in its next issue, on sale October 27.
Get daily insight, inspiration and deals in your inbox
Get the hottest deals available in your inbox plus news, reviews, opinion, analysis and more from the TechRadar team.