208 posts • joined 18 Oct 2012
So.. Am I missing something, or does Seagates's split actuator thing perform the same as two half-sized drives in striped raid-0?
I thought harddrives were more like optical drives these days, that they actually track the position of a track, so that it allows for the disc/platter to even spin slightly off-centre.
Re: Mixed signals on CPU's
So basically every CPU since the Pentium Pro / Pentium II?
Get a CPU older than 20 years and you'll be fine.
Re: Handbrake users beware
Funny, I thought video conversion would be minimally hit, as it consists mostly of:
read(very many bytes); process (very long cpu intensive code); write(very many bytes)
Where, if the read and write are implemented as sending big requests to the kernel, should be minimally affected. The processing portion of it is surely 99% of the whole processing time anyway?
I could believe things like a database would slow down, when it's hopping all over the place on disk looking for/writing data. I could believe facebook slows down alot, because browsers are doing lots of itsy bitsy tiny reads and writes to both disk and net, and lots of small updates of the screen to animate all the gifs and what not.
Re: Lots of testing work to be done then?
It's the move to and from kernel that is penalized, time spent inside kernel and time spent outside kernel isn't penalized. Of course, hardly any system monitoring programs will tell you how many syscalls or context switches different programs cause.
Re: "To provide a better experience to customers"
What's preferable, phone unexpectedly shutting down without warning, or phone slowing down to avoid sudden shutdown?
The big issue is of course that the user wasn't notified in either case, on any brand of phone (androids also suffer from thus when their battery gets old, sudden shutdowns despite having 30% left).
On the other hand, it's not an easy problem to solve. Unexpected shutdown means unexpected, even if there was an algorithm trying to collect data about the operating state of the cpu and all its peripherals, and recording battery voltages, when unexpected shutdown hits you lose the data. The hardware shuts down to protect both the battery (since they become unstable from operating at low voltage) and the CPU, ram and storage from corrupting data due to insufficient voltage.
AMD have a "clock stretching" feature in some of their CPUs, if the voltage inside the CPU drops the frequency slows down. It's mostly meant to allow them to operate with lower voltages and save power by not needing as big "safety margin" in voltage. Would be interesting to see something similar in mobile SOCs!
It's kinda remarkable that battery meters are still so bad at tracking the capabilities of an aging battery. On one hand, it's a kinda neglected area where manufacturers choose the cheapest component. On the other hand, it's a difficult problem! Batteries aged in standard cycle testing behave differently to batteries aged in real life. Batteries in real life age differently depending on how they're used and charged.
What do I mean by aged differently? As is well known, a battery's voltage sags when you put a load on it. The bigger the load, the more the voltage drops. The amount of drop is, for most part, a linear function of the load. When the battery is new, the sag is so small it makes no difference. The amount of sag can be described as internal resistance. More internal resistance means more sag.
On a new battery, the internal resistance stays nearly constant regardless if the battery is 100% or 20% full. Towards empty it becomes a bit higher. With an ideally cycled and aged battery, the capacity is lower, and the internal resistance is higher, but the internal resistance is still around the same order of magnitude regardless the battery is full or empty.
With batteries aged in real life conditions, where the battery might've spent a lot of time at 100%, a lot of time at 0%, a lot of time in heat, etc, the results on internal resistance will be different. The internal resistance might sharply rise as the battery discharges. From the initial situation with a fresh battery having a flat internal resistance curve vs state of charge, to having a inclined straight line describing an increased resistance at empty, to having exponentially increasing resistance towards empty.
Why does this all matter? Because currently there's no battery meter chip that can take into account anything except the "internal resistance is the same regardless of how full battery is" situation. Most chips don't account for internal resistance at all.
So from an engineer's perspective, if Apple is actually tracking actual battery performance and managing to make their system adapt to having a smaller and smaller power budget, that's kinda impressive. Makes me glad someone is finally paying attention to adding more sophistication to battery management systems!
Of course, they could just have put in a battery twice as big and they wouldn't have had issues with shrinking power budget for the phone's "lifetime", and they wouldn't need to consider aging battery.
Soon marketing will have made more radio Gs than the storage Gs on the device itself.
Re: Battery shape?
It's more like, the more you focus on a battery's ability to deliver high peak power, then more you take away from its ability to to store energy. It's a tradeoff. Mobile phones very much favour capacity over power, Apple perhaps more so than the rest. Also keeping in mind that Apple has very powerful CPU while at the same time having "unremarkable" battery capacity, in remarkably small space, it pushes everything to the limit.
In this case they pushed it perhaps too far, when some batteries have aged a bit too fast.
Re: $20 per transaction fee
I remember back in the day when some nerds were trying to explain the usefulness of bitcoin, they argued speed of transaction and cost of transactions as superior to regular banking. At the time I thought the argument was dubious at best, as bank transactions were on the order of minutes, and transactions usually included with other services anyway, costing nothing extra.
"But bitcoin isn't vulnerable to the whims of governments and central bankers!" - well sure, but is the whims of the collective speculative investor hivebrain any better?
I think the biggest issue is the sheer number of passwords required. The average person probably struggles to remember more than 2 "difficult" passwords. Add to that, that every little thing wants you to make a user account and password, so you end up with hundreds.
Re: Tesla semi?
The batteries should accept charge at the same rate as the stated acceleration, so 100 to 0 in 20 seconds. That seems like very aggressive braking under normal circumstances.
Likewise, if it can maintain a specific speed going up a hill, it can maintain the same speed going down the hill without the use of friction braking.
Laser altimeter is the kind of thing a hobbyist would use, since hobbyist radars make ofcom/FCC/etc annoyed. GPS and barometric sensors aren't that good for approaching the ground at a ensured survivable rate.
So is this serious, or will it be as widely used as the evil bit on IP level?
Re: planet is surrounded by spy satellites
I once found a submarine on Google Earth. It was just outside Tokyo bay. Always takes me awhile to find it again though.
The spy satellites are more concerned with photographing military targets. Even so, had they been tasked with photographing the ocean, you would've needed quite some luck to have taken a picture of the right area before the debris got scattered out blending in with all the other debris floating around.. Not to mention the manpower needed to sift through all those photos. There was a crowd sources effort to look through satellite photos, which turned up empty.
Was out shopping for a new phone for my elderly father. At some point he had wandered off into the shop of the third largest operator.
When I informed the shopkeeper that yes, that's exactly the phone for him (a Doro), we can't really buy it since we do need to use the competing operator for coverage concerbs.
The shopkeeper cheerfully said he's happy to sell the phone even if we put competitor's SIM in it.
Now I understand why some 3D printers have SD card slot for storing the print while it's printing!
Re: I'm confused
64-bit mode removes some old backwards compatibility, and many new features are only available in 64-bit mode.
It's slowly moving towards being two entirely different CPUs, with 32-bit mode being left as it was, and 64-bit getting all the new features.
Anyone remember typing "go64" on a Commodore 128? :-)
Re: "platform of built-in solutions to optimize your Windows 10 investment"
On mine it "upgrades" the synaptics touchpad drivers to a version which turns the touchpad on and off rapidly. The blinking notification onscreen (at around 20 on/off cycles per second) is annoying enough, it also makes it harder to click things so I can roll back to the working version.
The 46mA is actually impressively strong. It's in the potential death territory (but not certain death, far from it), if the shock went across a heart instead if through an arm.
Re: Competing with their own customers
I wonder if it's google saying "If you guys won't do it right and be responsible about security and updates, then we'll just do it ourselves."
These tariffs are available elsewhere in Europe. Suppliers offer different "day-ahead market price + margin" tariffs, for example.
It works as long as a minority uses those tariffs, and as long as demand isn't too flexible (everyone choosing to use all their power at 3am to charge Tesla powerwall when it's cheapest).
Re: Not applicable in any place I lived...
There are battery powered electronic versions of that valve, including ones with wireless control through a central "router", and the facepalm quality mobile apps. I know one manufacturer already deprecated their first gen versions of this, leaving expensive systems vulnerable. I'm looking at you, Danfoss.
If you took an average sized UK dwelling, and installed good insulation, and subjected it to the mild UK climate, you'd only need the waste heat from the kettle to keep warm.
Re: Still not happening
Which requires that someone is constantly present and awake to monitor the temperatures, so that when the family returns from work/school the water pipes haven't frozen over.
So obviously in this case they actually detected test conditions by some method (front wheels moving, rear wheels stationary, obd connected?), and switched engine to lower emissions...
I wonder what the outcome would've been if they instead had heavily optimized the engine to run the cleanest at exactly the test regime conditions, but provide increased power and higher emissions when the driver pushes the throttle and deviates from the teat conditions?
It would on one hand be a sort if cheat, but on the other hand one could argue that it would be reasonable for the test, that the authorities designed, to reflect the most common expected use, and that it made sense to optimize the engine for these conditions...
I myself tend to use the style which BMW (iirc) found to be most efficient, pedal to the floor, shift up before 2000rpm until in highest gear.
Re: Lithium batteries are last century's technology
There are phones with large batteries available. Hardly anyone buys them. Thus, battery capacity stays low on most other models. What's the point making phone with big battery when everyone is fine with 8hour life?
Software video encoding typically produces superior quality for a set bitrate, whereas GPU video encoding is quick and dirty.
2 year life
According to the article, FP1 was still sold in 2015. It is now 2017, and the device is unsupported. If someone had bought it on a 2 year contract from an operator in late 2015, it might've entered unsupported status before the customer had even paid it off! Not to mention statutory warranty periods..
Why not? It works like autopilot on a ship or on an airplane, The only other autopilots I can come to think of.
Airplane autopilots will happily fly into other airplanes, with the collision alert sounds blaring, or halfway into a mountain before giving up the controls and telling pilot to do something in the last second.
Re: Wrong comparison
They already do, pretty much. Their sleep states would give around 2-4 weeks battery life, It's just that they power up constantly to check farcebook, twitters, instagrams, snapchats, whatsapps, Skype, telegram, google+, gmail, oemaccount, google play, weather widgets, location, etc...
Don't forget the last gpu cryptomining fad propped up AMD's sales for a year, drove up prices and killed availability.
I haven't been following very closely, last time only AMD GPUs were useful, are both brands useful this time around?
There is no metallic lithium in Li-Ion batteries - normally.
It is possible to generate metallic lithium by overcharging. This makes the battery quite volatile for future use.
Another trick you can do is over discharge, which causes the copper to dissolve. On charging it back up again, the dissolved copper precipitates in random places, and may or may not cause a short. Slower version of Russian roulette.
Out of interest, how much would it cost to set up 2FA for a single user on a single server (raspberry pi) with mentioned Rsaid?
So... We know that Intel CPUs will throttle down at around 100C... So the question is, did the atom CPU fail to throttle and to into thermal runaway, or did the manufacturer fail to keep the battery protected from the 100C CPU?
Considering the scarcity of public IP addresses and increasing numbers of NAT boxes everywhere, it's rather impressive that so much is still open to public internet.
This article puzzles me.
Is it common these days to expect a server, dedicated, vps or VM to have preinstalled firewall? Or is it expected that there would be a separate firewall in front if it all?
If anything, I would've thought the expectation would he firewall and nat-free so you can have bidirectional communication with clients from the internet...
Could someone enlighten me please...
The problem with formally proving a system is that by the time you've completed it, the specification turns out to be wrong and has changed 27 times over 7 different corporate/government regimes.
Anyhow, I've often had arguments that have gone a bit like:
"Hey what are you doing here, that results in undefined behaviour"
- "It's okay, I tested it and X happened every time"
"It's still undefined, it could change any time in the future"
- "What why, surely they wouldn't make backwards incompatible changes to the OS?"
"Undefined is undefined, they could make the compiler generate code that erases the hard drive and they'd still technically be standards compliant"
- "You mean I have to actually read specs and learn, not just try random stuff until something works?!"
- "Being a developer sucks!"
I have to admit failure here, I simply can not comprehend the dice example, how 6 and 6 would be any less, or any more likely to come up than 6 and 5, or any other combination?
It gets more complicated than that. I used to think suck per watt would be the thing to measure (and do you want to measure volume per time, or static pressure?)
With less suck, but with a rotating brush, you get surprisingly good results, and better results at removing dog hair than a traditional powerful suck.
On the other hand, that gives terrible results on getting sand out of a carpet. Except if it's a very smooth and non-porous mat.
So you'd probably want to include a range of different dirts on different surfaces, spread onto and into the surfaces using various methods, weigh before and after result, and consider energy and time used, and the amount of particles exhausted or thrown up into the air.
Maybe suck per watt would be easier.
I used to enjoy playing around with lossy media such as CDs tapes and usenet, throwing more and more parity at it, and sometimes deliberately abuse the media to introduce more losses, just to see how much could be wrecked and still have a human viewable picture or audio left...
With that said, it would be interesting to see what a modified CD drive would be able to pull from a disc cracked and carefully put together again. Modified, because you'd want it to ignore luxuries like adressing and error correction/reporting and just get a raw bits (or probabilities of a bit or no bit) back..
I imagine it would be impossible to get the tracks aligned again, so it would in best case be randomly jumping to different track and getting stuck like a grammphone skipping tracks...
I wonder how well the metal layer is bonded to the rest of the disc, if a crack and would severely distort it on the rest of the disc too.
I remember around 2002 or so Redhat 6.1 ... 6.2 came with portmapper by default on 111, probably the most common reason why machines got taken over back theb.
Funny how little things have changed in 15 years.
What's noteworthy to me is how the hardware specs are higher than those of most "normal" Windows 10 laptops people buy.
Re: Fixed for pennies
Actually, from the article I get the impression that what the device had was exactly the above: A MOV.
The thing is, they get more and more sensitive over time, and WILL become fully conductive during normal voltage, eventually.
In a properly designed device you make sure that the resulting fire or explosion doesn't spread, and that there's a fuse that disconnects it when the short circuit does happen.
That's what the "Protection OK" light on a surge protector is for, once the MOV shorts and causes the fuse to blow, the light no longer gets power and goes out.
As for Office365, does anyone else experience every single desktop getting logged out and forgetting their credentials?
Anyone else experienced having every account in a company scrambled, licenses randomly reassigned between accounts?
Happens about quarterly. Luckily small business with around 20 users, and luckily I'm not the one that has to sort out the mess when suddenly nobody's excel will run.
Just got a brand new Kaby Lake windows 7 laptop 2 weeks ago. Timing sucks.
I needed the newest Siemens TIA portal software for work. It supported Windows 7 and 8, 64-bit only. My trusty engineering laptop ran 32-bit windows.
Call to supplier and I get a Windows 7 pro kaby lake laptop the next day, because skylake and kaby is all they have. Well, they only had one model with Win7 license anyway.
A week later, and Siemens finally gets head out of ass and releases Windows 8.1 and 10 compatibility (well, atleast until creator's update comes and kills it).
I wonder if it's a bit like how caterpillar has the same key for all vehicles, so that you don't have to spend time on finding the right one.
Re: The Reg
It took me 3 attempts to upvote this because of that same banner jumping text up and down. The posts after your post fit a few accidental up votes. Oops.
Often it loads covering the article headline and the first few rows of text, and stays like that for quite a bit. Sometimes I get to close it and click "ad covered content", but usually itnjimps to where it's supposed to be if I try to X it...
"AI" is whatever would have seemed like magic last year.
Once it actually works it stops being "AI" and gets called something else. Pattern matching algorithm, massive statistical database, whatever.
As for support call centres, if things just worked in the first place we wouldn't need so much of them. The cheaper it gets to provide call centres, the worse the products/services will be.
Re: Milking It
As someone working in a so far robot-free plant, situated next door to a fanuc shop, that was interesting news and I will certainly demand manuals if those fanucs try to get in.
If you know, what robot manufacturer UA the friendliest for maintenance technicians armed with a netbook, pieces of string and duct tape?