By far the majority of PCs use 32-bit processors, because despite AMD’s efforts to push 64-bit CPUs into the marketplace early, Intel’s first widely-promoted 64-bit CPU is the just-released Core 2 Duo.
PC users will now have to choose between a PC that can play high definition content (64 bit) versus one that can potentially run older devices that only have unsigned drivers available (32 bit).
“Signed drivers” are ones that have undergone a Microsoft quality-assurance process and received a digital certificate that certifies them as stable for installation on 64-bit Windows.
Microsoft’s move to drop support for playback of studio-released HD movies on Vista is likely to anger the large number of people who were hoping they could use their existing 32-bit PC with an upgrade version of Vista.
The surprising disclosure was made by Senior Program Manager Steve Riley during a presentation on Windows Vista security at Tech.Ed 2006 Sydney today.
“Any next-generation high definition content will not play in x32 at all,” said Riley.
“This is a decision that the Media Player folks made because there are just too many ways right now for unsigned kernel mode code [to compromise content protection]. The media companies asked us to do this and said they don’t want any of their high definition content to play in x32 at all, because of all of the unsigned malware that runs in kernel mode can get around content protection, so we had to do this,” he said.
Riley then attempted to pre-empt audience concerns over the newly imposed limitation by asking how many of the Tech.Ed attendees currently played high-definition movies at home.
“How many of you have a DVD player that you know can output a proper 1080 line non-interlaced?”
No-one raised their hands.
“OK… look around. By the time that stuff becomes popular, it’ll no longer be an issue because everyone will be running 64-bit Windows,” he said.
However, earlier in his presentation, Riley had explained why Microsoft had decided to let unsigned code run in 32-bit Windows, but not in 64-bit Windows.
“Imagine how difficult it would be for you [the Tech.Ed attendees] to update your environment. It would be a non-starter, right?”
“We can’t do that [lock out unsigned drivers from 32 bit Windows]. The app-compat hit, as we say in Microsoft, would be far too great if we did it in 32-bit Vista.”
In an interview hastily organised by Microsoft public relations staff after they learned APC was planning to run this story, Riley was at pains to point out that Blu Ray and HD-DVD were storage media and “you could put an MPEG-4 movie on them and play them on a 32bit Vista PC just fine.”
But he conceded that a commercially-produced BluRay or HD-DVD movie with next-generation high definition protected content wouldn’t play on a 32 bit PC.