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Comment: Re:What in the actual fuck! (Score 4, Informative) 152

by otuz (#49468745) Attached to: Sharp Announces 4K Smartphone Display

About 17Hz or a bit more with most single DVI outputs, although 14Hz is the minimum required for DVI by actual spec. Twice that with two DVI signals. The display itself does the thing by partitioning the display; either 3840x2400@14+Hz or 2x1920x2400@28+Hz side-by-side or 4x1920x1200@60Hz in a 2x2 grid, capped by the display at 41Hz or 48Hz depending on the model.

Comment: Re:What in the actual fuck! (Score 2) 152

by otuz (#49468731) Attached to: Sharp Announces 4K Smartphone Display

I have one of these (rebadged T221; ViewSonic VP2290b), got it second-hand in 2008 or 2009. It's not just the display connection bandwidth, the 41Hz and later-model 48Hz limit is from the display internals. They use huge custom FPGA logic chips to drive the signals, which are apparently not fast enough for more than that, although some of them can be overclocked to drive almost 60Hz. Without these internal display limitations, four DVI cables have enough bandwidth to run one at 60Hz (4x1920x1200@60Hz).

I haven't bothered to drive mine with four cables, because with just two (1920x2400) DVI signals I get it up to 34Hz, but I've scaled it down to 30Hz, because it's evenly divisible by 60Hz. In normal desktop use, it's fast enough. For gaming and movies, there are other displays.

Eventually there'll be a point in resolutions when it's bandwidth-wise better to have the GPU on the display side and just run some future thunderbolt-esque long cable than running even higher bandwidths to the display. An 8k display with a resolution of 7680x4320 would require 50Gbps of bandwidth to be driven at 60Hz at 8bpp or 60GHz at 10bpp. The actual required data rate between the CPU, RAM and GPU is much lower nowadays, especially because most of the heavy lifting like rendering and video decoding is done by the GPU.

Comment: Re:Can't directly compare PC and phone sales ... (Score 1) 511

by otuz (#45979319) Attached to: Apple Devices To Reach Parity With Windows PCs In 2014

iPhone 4 and newer iPhone battery replacement is fairly trivial:

1: Buy a battery and a pentalobe driver or bit from dealextreme or ebay for about $10
2: Uscrew the two case screws
3: Slide the back cover off
4: Unscrew the battery connector screw
5: Replace the battery and reassemble the back cover

I've done it about once a year on my iPhone 4, once the average recharge interval goes from about five days to about three days.

Comment: The article didn't make sense and has been updated (Score 1) 90

by otuz (#44000607) Attached to: iPhone Apparently Open To Old Wi-Fi Attack

UPDATE: Vodafone has told TechWeek why it believes its users are safe: “The embedded configuration that is applied for our iOS devices ‘1WiFiVodafone1x’ and ‘Auto-BTWiFi’ are locked to ‘EAP-SIM’ authentication which is a bi-directional authentication protocol.

“Man-in-the-middle attacks rely upon a hacker setting up an access point pretending to be the configured AP [access point].

“With EAP-SIM configured, the device will send the AP a challenge to make sure that it is Vodafone that it is connecting to. This transaction is resolved with our network, which sends back the response to the challenge and its own challenge. The handset then responds to the network challenge and providing all of these challenge response pairs work then the user gets access. If the initial test for it being Vodafone fails, the device doesn’t connect.”

APL is a write-only language. I can write programs in APL, but I can't read any of them. -- Roy Keir

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