Month: December 2017

Enlarge (credit: Lucasfilm)

The official Star Wars Twitter account shared one final short trailer for Star Wars: The Last Jedi yesterday, commemorating "VIII days" until the movie's premiere. It's only 30 seconds long, and it's in that infuriating social video aspect ratio, but the new teaser does include some perplexing new material.

While the new spot uses a fair bit of footage we've seen in previous trailers, there are a handful of new shots—one of them quite provocative for the types of fans who revel in speculation and theories. So if you want to go into each shot fresh, watch before reading. And if you want to go into the movie totally fresh, don't watch the trailer at all.

Trailer details

Spoiler porg!

In this trailer, we get several more shots of Poe Dameron in action behind the throttle of his X-Wing—they comprise the majority of what's new here. But we also get a glimpse at a stormtrooper preparing what looks like an energy axe, for lack of a better term.

Enlarge (credit: Nvidia)

Although Nvidia launched its 21 billion transistor Volta GPU architecture back in May, until now the chip has been used exclusively in compute cards—specifically, the Tesla V100 cards, which cost about $10,000 for the PCIe version. But now Volta GPU is available in a graphics card: at the 2017 Neural Information Processing Systems conference, Nvidia CEO Jen-Hsun Huang announced the Titan V, a $3,000 golden video card making the same GPU—the Volta architecture GV100—available to regular end users.

Unlike the Tesla cards, the Titan V is a proper graphics card. It has three DisplayPort and one HDMI outputs, it uses the standard GeForce driver stack, and it will play games. It'll probably play them quite well, although Nvidia hasn't made any gaming performance claims thus far. That's because, although it's a graphics card, it's not really being aimed at graphics applications. Rather, it's being aimed at the same kinds of GPU-based computation (especially machine learning) applications that the Tesla cards are meant for, just on a slightly smaller scale. Titan V would be used in a workstation PC, rather than a compute cluster in a datacenter.

With these similar roles in mind, it's not too surprising that Titan V's specs are extremely similar to Tesla V100's. Both cards have 5,120 compute cores, and both have 640 machine learning-oriented "tensor cores" that specialize in 4×4 matrix arithmetic. Exact clock speeds for the Tesla cards aren't known, but Titan V can boost to 1.455GHz, slightly more than V100's 1.370GHz. It's the memory subsystem that has the biggest difference: Titan V has 12GB of HBM2 memory, with a 3,072-bit memory bus. Tesla V100 has 16GB of HBM2 and a 4,096-bit bus. The Titan's memory is also a hair slower, clocked at 1.70Gb/s compared to 1.75Gb/s.

Enlarge (credit: Thomas Claveirole)

Is Bitcoin a bubble? It's a natural question to ask—especially after Bitcoin's price shot up from $12,000 to $15,000 this week.

So we decided to ask a couple of experts on bubbles what they thought: Brent Goldfarb is a business professor at the University of Maryland, and William Deringer is a historian at MIT. Both have done research on the history and economics of bubbles, and they talked to Ars by phone this week as Bitcoin continues its surge.

Both academics saw clear parallels between the bubbles they've studied and Bitcoin's current rally. Bubbles tend to be driven either by new technologies (like railroads in 1840s Britain or the Internet in the 1990s) or by new financial innovations (like the financial engineering that produced the 2008 financial crisis). Bitcoin, of course, is both a new technology and a major financial innovation.

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A month ago, Google started warning developers about a coming crackdown on apps that use the Android accessibility APIs for things other than accessibility. For years, the accessibility APIs have been a way for power-user apps to hook into the operating system, but Google apparently had a change of heart last month, telling developers they had 30 days to explain how an app using the Accessibility APIs was helping a user with disabilities or face removal from the Play Store.

After a public outcry, Google sent out another email to developers, saying it is now "pausing" this decision for another 30 days while it considers "responsible and innovative uses of accessibility services." Google hasn't made a decision one way or the other yet, but for now it is asking that developers who use the Accessibility APIs for non-accessibility purposes add "an accompanying disclosure to describe the app functionality that the Accessibility Service permission is enabling for your app."

Google is also asking that developers send the company feedback, ending the email with: "If you believe your app uses the Accessibility API for a responsible, innovative purpose that isn’t related to accessibility, please respond to this email and tell us more about how your app benefits users. This kind of feedback may be helpful to us as we complete our evaluation of accessibility services."