ARM versus Intel? No contest, says Linus Torvalds

Intel x86 still Torvalds' "favourite architecture"

ARM is unlikely to dislodge Intel from heavyweight computing as the Intel "infrastructure" is more unified and open, according to Linux creator Linus Torvalds.

Torvalds made the comments in a one-on-one Q&A with David Rusling, chief technology officer at ARM tools vendor Linaro, in response to a question about his "favourite architecture".

"It's because of the infrastructure. It's there and it is open, and it's open in a way that no other architecture is. The instruction set and the core of the CPU is not very important," said Torvalds.

"It's one of those big differentiators that people fixate on but it really doesn't matter than much in the end. What matters is all the infrastructure around the instruction set, and x86 right now has it and has it at a lot of different levels.

"ARM has it at the low end. There's really no question that if you are in mobile you are pretty much ARM...

"[But] I've been personally pretty disappointed in ARM. Not as an instruction set, although I've had my issues there, but as a hardware platform it's still not very pleasant to deal with... It doesn't have the same kind of unified models around the instruction set that we have in the PC space. It's getting better, but part of it is just the market itself," said Torvalds.

The ARM market, he added, historically didn't value rigid compatibility as highly as the PC market, where the need for one application to work on every PC with no problems was a key to it eventually becoming the de facto standard.

"When you don't have compatibility as being a huge deal from hardware vendors' perspective you end up having a very fragmented market... Realistically, today x86 and ARM are the two big ones. Power has a lot of developers behind it... But we support pretty much everything," said Torvalds.

He added that he wasn't "emotionally attached" to any one architecture. Rather, as a developer, it's the development platform that counts rather than specific chip architectures.

However, the ARM ecosystem has improved, he said.

"ARM has gone from being the biggest 'pain point' in the kernel for me to being something I don't need to care about. That's how I want it to be.

"We all know about the issues with vendors who add millions of lines of code and then never actually gets to me. That part is not working, but that's not something I feel is the kernel community's burden to bear. That's something I hope the vendors will end up fixing because it's their problem..."

Tovalds also answered questions about his current role and management style. "When we have a problem we need to talk about it very publicly and make sure that people know it's a problem. It's a part of how I work and I think it's important," he said.

But Torvalds admits that he doesn't write much code for the Linux kernel these days but, rather, sees his role as project management - making sure everything happens.

"My job has changed a lot over the 25 years or so that I have been doing Linux. That's part of why I like it - I don't do the same thing any more... If I neverever write another device driver in my life I will be very happy because I've done that [but] I can't do it again.

"I really loved doing it 20-plus years ago. I don't do it any more and I don't want to do it any more," said Torvalds.

Instead, Torvalds sees his role in the development of Linux more in terms of communications. "I always though I was the complete geek: shy and didn't want to talk to people.

"It's actually true. But when I can talk to people through email and don't have to look at them I'm okay and I really enjoy doing communication.

"I read email. I write email. I try to get people to be on the same page and when they are not on the same page, I try to nudge them a bit. It's the greatest job ever," says Torvalds.