Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
×

Comment Re:Uh? (Score 1) 734

I live in an area without brownouts, and have a house shaded by some large trees. What benefit do I get for buying you stuff? Sounds like someone trying to justify legalized theft. I hope you at least researched the manufacturer of the panels to make sure they're not dumping chemicals into the villages of developing countries. http://www.washingtonpost.com/...

Comment Re:Efficiency. (Score 1) 937

Volkswagen, with their 1-liter car project, produced a limited edition car with a drag coefficient of 0.189. One of their prototypes had a drag coefficient of 0.159. The production car is a diesel/electric hybrid that is estimated to get 260 mpg (US), or running on diesel alone 120 mpg.

Comment Re:meh (Score 1) 365

The hardware company may not have signed a contract yet. You don't want to just give something away to the customer when they haven't bought it yet. They're probably trying to establish design and build costs, so they will have an idea profitability and feasibility before locked into a contract to buy something they can't sell.

Comment Re:Why don't they know? (Score 1) 365

The electronics manufacturer probably hasn't seen the algorithm at this point. I assume they're still trying to figure out things like design cost, build cost, and feasibility before making a commitment to buy, and the software company doesn't want to give it away without a contract for payment. I would add up all the different operations of each type in your algorithm, along with some information about looping etc. and present this to the hardware company, but you would have to get a careful balance between giving them enough information to help and enough to build it themselves.

A hardware implementation can vary widely for a single algorithm. For example there are many implementations for running x86 instructions. A Haswell chip should run the same code that a 286 does, but with more transistors, higher IPC and a modified algorithm. If you look at closer processor generations, you may even see a repeated algorithm at some points.

Comment Re:Hard to believe (Score 1) 804

I can hit the $11,000 price point with a 1TB PCIe SSD or beat it with 4x240 GB SATA SSD's. Although I did skimp a little (about $300) by using slower RAM, my system can be upgraded to 128GB or more if you fill the second CPU slot, and I went with a standard tower. How many people have a use for a $10,000 workstation being small and portable? If you really want a nice system you can move, then bundle it with some sound equipment in a small rack.

The off the shelf FirePro W9000 that it is being compared against is a more powerful card than the D700. If you're running two of them, the DIY PC will have 8 TFLOPs (single precision) and the Mac Pro 7 TFLOPs. Considering I can get the PC parts for only an extra 15% cost, and that AMD is charging a HUGE premium ($3000 vs $1410) to go from 3.23 TFLOPs and 4GB RAM to 4 TFLOPs and 6GB RAM. That last bit of power is always expensive, and I could hit the price of the Mac by using 3x W8000 cards, while providing 38% more GPU power.

As long as we're swapping out top end parts for multiple smaller parts, I can go with 2x 2.8GHz 10-Core Xeons and 3x W8000 Cards. I get 73% more CPU power, 38% more GPU power and a faster disk array for the same money. Plus, as a $1,000 add-on I can get 18TB RAID-6 storage. For another $6,000 I can also double the RAM and upgrade to dual NVIDIA k6000's (12GB RAM, 5.2 TFLOPs each0. Given that the only benchmarks I found show the W9000 regularly losing to the older Quadro 6000 and that labor costs and potential returns will dwarf workstation prices, this is probably a good extra investment.

Comment Re:BTRFS filesystem (Score 1) 321

I have seen both Dell RAID-5 and Sun RAID-6 arrays fail with 3+ simultaneous disk failures each. Google ran a Petabyte Sort benchmark in 2008 (6 hours to sort 10 trillion 100-byte records) and was not at all surprised that they had at least one hard drive failure on every attempt (4+ drive failures per day). I have seen enterprise tape systems fail to read their data (hopefully there was redundancy, but I don't know). I have seen backup systems have major performance glitches and fail to restore within their needed time frame. Facebook, for example, only has a few seconds to recover from a failed server before customers might get angry, and has built systems to handle it because it's necessary to provide a good service. The major players who are succeeding and profiting at giving away free services to hundreds of millions plan that all data storage will fail regularly, and plan accordingly.

A little primer for those of us who haven't kept up with new storage technologies since the 90's.

Google deals with enough data that they cannot consider any of your technologies reliable enough. Five years ago, they were already processing 20PB of data every single day with map reduce, and if you have to buy enough systems, even the best RAID6 SAN systems will break regularly. Statistically, a small chance repeated often enough gives you a virtual guarantee of probability. Google generally doesn't bother with expensive technologies like SAN's and RAID, or even bother with enterprise drives (spinning disks -- they probably use an enterprise PCIe flash). You can make what you want of the enterprise drive decision, but I'm pretty sure I've read from at least a couple of sources that enterprise drives are just as prone to failure as regular drives. The major differences are warranty and firmware (e.g. supporting RAID friendly reads). Numerous sources have substantiated that the manufacturers' MTBF numbers are pure marketing fiction. They probably boast a lower error rate, but I have not seen a comparison, only reports that they are off by several orders of magnitude.

What Google does is avoid any redundancy in their machines and take the "redundant array" to a whole new level: Redundant Array of Inexpensive Servers. Multiple copies of the data are written to different servers in different cabinets, and with each data block a checksum is stored. Every time the data is read, the checksum is verified. This way you know with 1 single read if you have bitrot, and can correct it with 1 good read. Now you no longer have to keep comparing 3 copies of the data to correct bitrot. The Hadoop project copied this with their HDFS, and many other large scale technologies have followed suit.

At a desktop level, ZFS, BTRFS and (I think) Windows Storage Spaces do something similar, combining RAID technology (0/1/5/6 maybe 1E) with checksums inside the file system. If a drive fails or even just that the checksum doesn't verify there can be redundancy to attempt to rebuild from automatically in the file system, giving you a better data guarantee than any RAID card I have seen. If the journaling is done correctly, it shouldn't be susceptible to losing data from a power loss either, but home battery backups aren't too expensive. The OP was asking specifically about bitrot. A lot of URE's (uncorrectable read errors) get labeled and treated as bitrot, but it sounds like data he has previously verified is now corrupt (actual rot), not that the reason for corrupt blocks matters once they are corrupt. Bitrot happens more frequently when you don't have such stringent environmental controls in your home as you would in a data center, and I have personally seen it with only 10's of GB of my data.

In my experience, data that is backed up and archived, isn't a prime target for user error nor gross negligence regarding data backups. The user is definitely experiences some sort of URE. In this case, a proper file system is quite important for protecting the data. I would recommend setting up a multi-drive NAS using ZFS (there is probably a distro build for this) and a second set of drives for archiving data to, where you cannot delete the contents. Then you need to regularly scrub the data to correct errors and you might want to check for SMART errors (scan errors and reallocation counts) as well. You should be able to get this information emailed to you, but it probably requires a little scripting. Storage Spaces on Windows might be an alternative, but I know little about it. If nothing else, writing scripts to manage everything will be a pain in Windows if Microsoft hasn't built it as a feature. If you want to protect against a disaster in your house, you may be able to synchronize the data to another ZFS array in another location, preferably an automatic solution over the Internet.

An online solution will handle all of this for you, but I do not expect it to be cheap. With some document retrieval trade-offs, Amazon Glacier would probably be the cheapest at $20/month. If you don't mind a maximum photo size of 2048x2048 (800x800 w/o Google+) and maximum video length of 15min, then these don't count towards your storage limits on Google Picasa.

Comment Re: Firechrome (Score 1) 381

I have a friend who never paid anything for many months of renewed free trials because he would always cancel in time. Eventually, AOL sent him a check with fine print that said by cashing it he agreed to another free trial. They were paying him to use the service.

Comment Re:Healthcare (Score 1) 356

The WHO ranks the US health care system #1 in responsiveness to the needs and choices of the individual patient (http://online.wsj.com/news/articles/SB10001424052748704130904574644230678102274). If that is nowhere near good, then what are you grading it on? Are you flunking it because Bill Gates, Warren Buffett, Larry Ellison, the Koch brothers and the Walton family aren't pooling their money to give you free access to healthcare?

Where the US famously ranked 37th in overall performance is more based on our funding and distribution than how well it responds to patients needs (by a factor of 5). We tend to charge people for health care somewhat based on what goods and services they use, instead of making Mark Zuckerberg fund unlimited access to a 30 year old bum living in his mother's basement dividing his time among reddit, McD's and drinking himself sick (notice no job). Actually, those factors only get the US downgraded to 15th in overall attainment. The remaining downfall is that the WHO thinks we should have a better health care ranking with our resources. (http://www.politifact.com/truth-o-meter/statements/2009/sep/14/paul-hipp/rocker-viral-video-mocks-us-37th-best-health-care-/)

To summarize...The UK sets records for wait times for a hospital bed. The US guarantees that anyone can walk into any emergency room with no money or resources and get excellent care (i.e. not sleeping in hospital hallways -- http://thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.com/long545.html). In the end, the WHO decides UK has better healthcare because there the harder you work to have more money, the more money it costs to get the same pitiful access.

Comment Re:You've gotta be kidding. (Score 1) 91

Actually (IIRC), the head of the MPAA thinks that making a backup copy of the DVD you purchased qualifies as fair use. It's the DMCA and the US Federal Government that considers it illegal. The Library of Congress is responsible as the legal authority of what is fair use, and I have yet to see them issue an exemption for making a personal backup. Rules on Blu-Ray are potentially different, as the CSS protection has been given exemptions that don't apply to other DRM. Rules on copying CD's are completely different, as it has no encryption to break before copying, and you are legally entitled to make a personal duplicate of any CD you own.

Comment Re:Article says the opposite? (Score 3, Insightful) 257

Reading the official Google Enterprise blog post linked to in the article that slashdot linked to "we’re extending support for Chrome on Windows XP, and will continue to provide regular updates and security patches until at least April 2015."

The official announcement is a minimum date for support, not a date where they plan on killing updates. Google isn't stupid. They make most of their money off of searches, so keeping a healthy ecosystem of usable web pages for everybody is in their best interest. A better web experience->more time online->more searches & visits to ad partners->more ad revenue for Google. A better web experience for more people was their primary reason for pushing Chrome into the market to begin with. I'm sure they would like to stop supporting XP at some point (e.g. Win2k isn't supported), but not if that would alienate too many people from having an up to date browser.

If there are enough computer users willing to buy antivirus for XP, then a company will be willing to sell it to them. Personally, I find antivirus to be too big of an intrusive hassle to deal with, eats too many resources, and does nothing against my primary thread of "potentially unwanted programs." Using Chrome, it has warnings for sites with malware and even once told me when I downloaded a virus. That's plenty for me. On rare occasion, I would like to be able to scan suspicious files on demand, but it's not worth the hassle of maintaining AVG or Avast for a year or two per scan (especially if Chrome did the last one for me). With so much of my computing in the cloud, it's much easier to just plan to reinstall everything when there is a problem or even partially automate regular reinstalls.

Comment Re: On the desert roads of Nevada, maybe (Score 2) 722

I'm pretty sure that the cars are constantly watching in front, back and both sides (too lazy to double check). They have been tested accident free (or at least fault free) in San Francisco, and successfully navigated Lombard Street. There is also driverless technology to allow them to see traffic (possibly just driverless traffic) around blind corners, obscured by buildings.

Comment Re: Hello? McFly?! (Score 1) 443

I cannot believe this one was neglected. Slashdot loses some nerd cred for me having to write in such a vote. Time traveling car is by far my #1 choice. I think self driving (also missing) would be number 2.

Comment Re:155 Forrester Clients (Score 1) 337

I suspect the overall use of office programs is declining, now that we have enough smartphones, tablets and laptops that are good enough to replace printed media much of the time. Such a change is bound to hit tech-savvy & price sensitive markets first. Why use excel when your analytic cloud crunches enough numbers to choke excel, while using live data or Google Docs could turn your spreadsheet into a simple web app? Why use MS Word, when you can either publish directly through WordPress or or through a web template system to deliver the document as a website? PowerPoint is losing some ground to niche presentation software, more novel presentation designs than the boring slide title with bullet points, and zany, Doc-Brown-like scientists who just draw their presentations on their hand (https://www.youtube.com/watch?v=wue2A4iMV5c -- well maybe 1 license tops).

The report would be more fair if it included some of the major web services replacing uses of office suites (e.g. WordPress, Wikis, custom web app, straight email without attached memo.doc, etc.) or at least presented some information on how much office suites are used.

Slashdot Top Deals

Kleeneness is next to Godelness.

Working...