Forgot your password?
typodupeerror

Comment: Re:Bad for GP-GPU computing (Score 1) 70

by rodsoft (#39528979) Attached to: Nvidia's Fermi Architecture Debuts; Nouveau Driver Already Working

Firstly, this new architecture (GK104) has a great number of cores (192 versus 32 of the Fermi architecture) sharing a single control logic within a stream multiprocessor (SM). Internally, each SM is SIMD, so this move is bad for divergent kernels, i.e., algorithms containing if-then-else constructs.

Actually this is not true. The SIMD width (warp size) is still 32. Divergent kernels won't suffer more with kepler. Maybe you got the wrong impression because nvidia's diagram with its architecture might be oversimplified.

Comment: Re:Not the best choice of languages (Score 2, Informative) 419

by rodsoft (#29118643) Attached to: Behind Menuet, an OS Written Entirely In Assembly

Go look at the assembler that some of these compilers produce. It's frightening to see the amount of overhead they cost on even simple assignment operations.

I doubt this kind of code is being generated in *RELEASE* builds. I often check the code being generated in inner loops and most of the time it's the Right Thing (tm). I'm pretty amused to see that the compiler can aggregate calls to sin/cos with the same argument into a single fsincos call, or vectorize some loops over arrays. That's like having the best of two worlds: human readable code that maps directly to the problem at hand AND very well optimized generated code. And given a new CPU and a compiler that understands its architecture and can take advantage of it, my higher level code will profit from it with minimal change. PS: higher level code -> C++

Programming

Should Undergraduates Be Taught Fortran? 794

Posted by CmdrTaco
from the or-spend-it-building-forts dept.
Mike Croucher writes "Despite the fact that it is over 40 years old, Fortran is still taught at many Universities to students of Physics, Chemistry, Engineering and more as their first ever formal introduction to programming. According to this article that shouldn't be happening anymore, since there are much better alternatives, such as Python, that would serve a physical science undergraduate much better. There may come a time in some researchers' lives where they need Fortran, but this time isn't in 'programming for chemists 101.' What do people in the Slashdot community think?"
Apple

Steve Jobs Takes Leave of Absence From Apple 429

Posted by timothy
from the get-well-soon dept.
An anonymous reader writes with this excerpt from Network World: "A number of sites are reporting that Apple's CEO Steve Jobs is taking a leave of absence till June at least. Speculation over Jobs' possibly failing health has run rampant in the past few weeks. Prior to the recent MacWorld show, Jobs said he had a hormone deficiency that had caused him to dramatically lose weight. In a memo today Jobs told workers his health issues are more complex than he thought." Reader Bastian227 adds a link to this letter from Steve Jobs on Apple's website, which also says that Tim Cook will be responsible for daily operations, though Jobs will remain involved with major strategic decisions.
Music

Attempt To "Digitalize" Beatles Goes Sour 434

Posted by timothy
from the when-you're-64-and-probably-not-even-then dept.
An anonymous reader points to this article at exclaim.ca, which begins "Just when Beatles fans thought the band were finally going digital, the Norwegian national broadcaster has been forced to call off the deal. Broadcasting company NRK has had to remove a series of 212 podcasts, each of which featured a different Beatles song and would have effectively allowed fans to legally download the entire Fab Four catalogue for free."
Power

"Black Silicon" Advances Imaging, Solar Energy 114

Posted by Soulskill
from the same-periodic-table-as-black-gold dept.
waderoush writes "Forcing sulfur atoms into silicon using femtosecond laser pulses creates a material called 'black silicon' that is 100 to 500 times more sensitive to light than conventional silicon, in both the visible and infrared spectrums, according to SiOnyx, a venture-funded Massachusetts start-up that just emerged from stealth mode. Today's New York Times has a piece about the serendipitous discovery of black silicon inside the laboratory of Harvard physicist Eric Mazur. Meanwhile, a report in Xconomy explains how black silicon works and how SiOnyx and manufacturing partners hope to use it to build far more efficient photovoltaic cells and more sensitive detectors for medical imaging devices, surveillance satellites, and consumer digital cameras."

Comment: Brazil government standing before open source (Score 1) 236

by rodsoft (#23285382) Attached to: Windows in Brazil Costs 20% of Per Capita Business Income
Open source is going well in Brazil because the government is really involved in substituting proprietary software for open source. It's happening wildly in the public sector. I was astonished when my girlfriend (which is doing civil service exams) told me that in her last exam there were questions regarding OpenOffice, instead of Microsoft Office, which was the norm a few years ago.
Being a country with a past (or present) of government corruption, I really don't understand why Microsoft's bribes don't work here (but work elsewhere).

Philogyny recapitulates erogeny; erogeny recapitulates philogyny.

Working...