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Comment: Same die, different result (Score 1) 191

by ericcj (#34677352) Attached to: AMD Radeon HD 6950 Can Be Unlocked To HD 6970

The C6950 and C6970 can come from the same wafer yet not be equivalent. Semiconductor wafers, like everything else that is manufactured, do not always come out exactly to spec. Instead they lie within a certain tolerance. The C6970 may require etchings that are 45 nm +/- 0.5 nm. The C6950 could have more relaxed tolerances, and only require 45 nm +/- 2.0 nm. Only 10% of the yield may meet the specifications required by the C6970. Also, the C6950 does not use as much of the die area, so that zone does not need to be to spec.

Assuming they have identical warranties, the C6970 probably goes through more rigorous burn-in and testing at the factory.

Comment: Re:The video card in question.. (Score 2, Informative) 187

by ericcj (#33414430) Attached to: Sorting Algorithm Breaks Giga-Sort Barrier, With GPUs

Chips on the GTX 480, C2050, and C2070 come from the exact same die and wafer. The C20XX GPUs actually run at a lower clock speed for 32-bit floating-point and integer operations than a GTX 480.

C20XX series hardware is intended for physics/science/engineering calculations, where double-precision is preferred. The C20XX series is 4 times faster at double-precision calculations than the GTX 480. This is the sweet spot it is tuned for.

Comment: Re:Motion blur and bloom effects (Score 1) 521

by ericcj (#30675454) Attached to: Framerates Matter

You don't get the wagon wheel effect with the naked eye.

Sure you do. Have you ever looked at the wheels of a car traveling next to you?

If our rods and cones were precisely synchronized, we would see perfectly sharp discrete changes in the rotation (like a stroboscope would produce). But we don't, it's blurry. The _net_ rotation appears to be clockwise, counterclockwise, or stationary, but there's some fuzziness in our perception of the current state of the wheel.

Games

The Struggle For Private Game Servers 125

Posted by Soulskill
from the let's-make-onyxia-fight-ragnaros dept.
A story at the BBC takes a look at the use of private game servers for games that tend not to allow them. While most gamers are happy to let companies like Blizzard and NCSoft administer the servers that host their MMORPGs, others want different rules, a cheaper way to play, or the technical challenge of setting up their own. A South African player called Hendrick put up his own WoW server because the game "wasn't available in the country at the time." A 21-year-old Swede created a server called Epilogue, which "had strict codes of conduct and rules, as well as a high degree of customized content (such as new currency, methods of earning experience, the ability to construct buildings and hire non-player characters, plus 'permanent' player death) unavailable in the retail version of the game." The game companies make an effort to quash these servers when they can, though it's frequently more trouble that it's worth. An NCSoft representative referenced the "growing menace" of IP theft, and a Blizzard spokesperson said,"We also have a responsibility to our players to ensure the integrity and reliability of their World of Warcraft gaming experience and that responsibility compels us to protect our rights."

Comment: It's Fun (Score 5, Interesting) 57

by ericcj (#28918341) Attached to: Carmack &amp; Mustaine Talk <em>Doom Resurrection</em> For the iPhone

Any hack can make a gorgeous looking 3D world. id has always led the pack by delivering that experience under real-world hardware constraints.

I downloaded this expecting a ported version of the 1993 Doom. I was pleasantly surprised and very impressed when a fully 3D environment with Doom 3 media loaded up.

NASA does super cool work, but they have billions of dollars and an army of PhD's at their disposal. We like MacGyver because he solves problems with whatever he's given. iPhone developers are given a 412 MHz ARM processor, 128 MB of RAM, a 3-axis accelerometer, and a touch screen.

I think John Carmack and Co. are excited about developing for the iPhone because it's a fresh technical challenge for them. DR is an impressive accomplishment. Given the hardware constraints, and the fact that the game needs to be fun, I'm not sure what I would have done differently.

Businesses

+ - Business + Booze = Productivity 1

Submitted by
theodp
theodp writes "Fortune's Stanley Bing gives President Obama kudos for settling a serious problem with a cold beer instead of the usual statements and meetings and a lot of positioning and much sober thought. Bing laments that we now live in a world where if a person has a drink over business, he or she has to be carted off to the sanitarium, or at least the Company's Employee Assistance Program. But business and the right amount of booze equals productivity, argues Bing, adding that the sooner we implement that equation, the sooner we'll be back on the road to growth and recovery."
Software

Cheap, Cross-Platform Electronic Circuit Simulation Software? 211

Posted by timothy
from the what-we-all-want-when-we-wake-up-in-the-morning dept.
dv82 writes "I teach circuits and electronics at the undergraduate level, and have been using the free student demo version of OrCad for schematic capture and simulation because (a) it comes with the textbook and (b) it's powerful enough for the job. Unfortunately OrCad runs only under Windows, and students increasingly are switching to Mac (and some Linux netbooks). Wine and its variants will not run OrCad, and I don't wish to require students to purchase Windows and run with a VM. The only production-quality cross-platform CAD tool I have found so far is McCad, but its demo version is so limited in total allowed nets that it can't even run a basic opamp circuit with a realistic 741 opamp model. gEDA is friendly to everything BUT Windows, and is nowhere near as refined as OrCad. I would like students to be able to run the software on their laptops without a network connection, which eliminates more options. Any suggestions?"

Top Ten Things Overheard At The ANSI C Draft Committee Meetings: (4) How many times do we have to tell you, "No prior art!"

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