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by Jim Manley
Fri Jan 15, 2016 7:32 am
Forum: Off topic discussion
Topic: Why is this Android Box as cheap as a Raspberry PI
Replies: 21
Views: 4954

Re: Why is this Android Box as cheap as a Raspberry PI

A 3.5 score(on a scale of 1-4(no zero)) is mediocre at best. With all the problems cheap power supplies have given Pi user this one may be no bargain. This is the real kicker and makes me want to use Linux instead of Android even for a bargain. Google maintains Android so makes it report your data....
by Jim Manley
Thu Jan 14, 2016 10:59 pm
Forum: General discussion
Topic: We're recruiting!
Replies: 52
Views: 6782

Re: We're recruiting!

Yeah, OK, ants. The world needs doctors, lawyers, politicians, service workers, and poets too. Let's not assume that a need for technicians equates to everybody needing to be a technician. Hey Douglas6 - I'm not sure what the bent of your response was, but it seems like you're in favor of education...
by Jim Manley
Thu Jan 14, 2016 1:20 am
Forum: General discussion
Topic: We're recruiting!
Replies: 52
Views: 6782

Re: We're recruiting!

I think what the RPF is doing is great, but I haven't got the skills to work in this field of work. I've asked in another thread if there's any plans for further education. The RPF are already modernizing the workforce with IT skills, if they had a program for career change and development that wou...
by Jim Manley
Wed Jan 13, 2016 7:20 pm
Forum: General discussion
Topic: We're recruiting!
Replies: 52
Views: 6782

Re: We're recruiting!

Hey texy - I'm sure that Heater isn't being sarcastic since this topic is all about job openings and qualifications, and he would never, ever venture off-topic to be mean. Plus, he would be surprised to discover that I've never listed the majority of my qualifications on the forum (as hard as that m...
by Jim Manley
Wed Jan 13, 2016 2:23 pm
Forum: General discussion
Topic: We're recruiting!
Replies: 52
Views: 6782

Re: We're recruiting!

OK, here's how we get you your next Director of Operations. I build a robot based on Pii, of course, and I use it via telepresence to attend meetings, visit everyone in their office warren pookas, and otherwise be a charming and likable fellow. Meanwhile, I perform the actual hard part of the job wh...
by Jim Manley
Tue Jan 12, 2016 8:08 pm
Forum: General discussion
Topic: Raspberry Pi Zero long term availability?
Replies: 80
Views: 14925

Re: Raspberry Pi Zero long term availability?

To heck with long-term availability, I'd like to see some short-term availability, as in being able to buy _any_ quantity, even just one, today or maybe this week! Liz said that as long as we keep buying them, they'll keep making them ... and we're not buying them because they're not making enough o...
by Jim Manley
Mon Jan 11, 2016 5:53 am
Forum: General discussion
Topic: Lighting An LED
Replies: 73
Views: 7013

Re: Lighting An LED

BTW Ohms law does apply to LEDs and any other device that draws power be it linear or not. I admire your tenacity for correctness. If only you were correct. The common or garden Ohms Law, as most people know it, states that I = V / R. This is clearly not applicable to a LED for which no "R" is spec...
by Jim Manley
Mon Jan 11, 2016 3:56 am
Forum: General discussion
Topic: sql queries in php
Replies: 4
Views: 1078

Re: sql queries in php

Is it really 'users'? Normally table names without ' ' in SQL! Actually, normally with backticks to identify a table, row or column identifier. The single quotes would indicated a literal value. Oh, and the whole query should be in double quotes too. mysql_query("INSERT INTO `users` (`username`,`pa...
by Jim Manley
Sun Jan 10, 2016 6:39 am
Forum: General discussion
Topic: 2 node raspberry pi supercomputer
Replies: 71
Views: 15173

Re: 2 node raspberry pi supercomputer

While one might have hoped for a faster than 200 mbps interconnect, 44 mbps is definitely sufficient for leaning about cluster computing and much faster than 4 mbps using ppp over a serial port. Hi ejolson - how do you expect to get 200 Mbps through an Ethernet interface that only has a 100 Mbps ma...
by Jim Manley
Sat Jan 09, 2016 7:56 pm
Forum: General discussion
Topic: Pi Zero Availability
Replies: 205
Views: 50080

Re: Pi Zero Availability

To Emma and anyone else who thinks it's just a matter of not trying hard enough If you have 1982 students desperate for a Pi Zero then you have a minimum budget of about $10,000?, more importantly you have near 100,000 mouths (or brains) to feed moving forward. Surely if you contacted the foundatio...
by Jim Manley
Sat Jan 09, 2016 1:01 pm
Forum: General discussion
Topic: Pi Zero Availability
Replies: 205
Views: 50080

Re: Pi Zero Availability

SonOfAMotherlessGoat wrote:Where can I send my 256Meg and 512Meg Model B's? (I'm actually serious, I'm down in OC Jim, I'll cover P&P to USPS Priority them to you.)
Even a 256 MB Original Flavor Pi B would be a big help. Thanks very much! PM sent with particulars.
All the Best,
Jim
by Jim Manley
Sat Jan 09, 2016 11:44 am
Forum: General discussion
Topic: Energy or Power Consumptions
Replies: 29
Views: 3039

Re: Energy or Power Consumptions

Oh, I just love it when a plan comes together ... even when it wasn't the original plan! :lol: It would be too complicated to thread all of the quite entertaining posts as quotes, so I'll just discuss the relevant concepts in turn. Jim's Law - DONE! Wow, I'm honored and humbled that the Academy woul...
by Jim Manley
Fri Jan 08, 2016 6:01 am
Forum: General discussion
Topic: Energy or Power Consumptions
Replies: 29
Views: 3039

Re: Energy or Power Consumptions

I don't believe it's as easy as you make out. Well, you can believe whatever you want, but I'm a scientist and an engineer, and I rely on facts and evidence ;). Actually, it is "easy" for those of us who are really old-school engineers. For those with more recent "educations", it may not be that "e...
by Jim Manley
Fri Jan 08, 2016 5:30 am
Forum: General discussion
Topic: Pi Zero Availability
Replies: 205
Views: 50080

Re: Pi Zero Availability

To Emma and anyone else who thinks it's just a matter of not trying hard enough, you're just completely uninformed on this subject. Some of us have to be up at the crack of dawn to show up at schools to let kids into our classrooms at 6:30 AM, we're stuck there all day teaching classes with no break...
by Jim Manley
Thu Jan 07, 2016 9:48 pm
Forum: General discussion
Topic: Energy or Power Consumptions
Replies: 29
Views: 3039

Re: Energy or Power Consumptions

No , it is not possible by software only. ghans Oh ye of little faith. Let's expand our minds a bit and recall what the Law of Conservation of Energy and Mass says - matter and energy can neither be created nor destroyed - they can be transformed, but not created nor destroyed. We just happen to ha...
by Jim Manley
Thu Jan 07, 2016 10:49 am
Forum: General discussion
Topic: Pi Zero Temp Spec ?
Replies: 60
Views: 18934

Re: Pi Zero Temp Spec ?

Mike - I'm a mechanical/electrical/software engineer with 39 years of experience, and you apparently have missed the raison d'être of the Pi: delivering as much computing power at as low a cost as possible for educational purposes, period. Any other successful uses are purely coincidental and a happ...
by Jim Manley
Thu Jan 07, 2016 9:31 am
Forum: General discussion
Topic: Webserver
Replies: 31
Views: 4356

Re: Webserver

Anyway, sounds like I have to try a little experiment to see how many simultaneous HTTP/HTTPS connections a Pi can handle. Got to back up my hand waving somehow right? Actually delivering data over all those connections is another matter....those are the hard rocks. Hey Heater - yeah, it would be i...
by Jim Manley
Thu Jan 07, 2016 8:30 am
Forum: General discussion
Topic: Webserver
Replies: 31
Views: 4356

Re: Webserver

I get about 94 mbps between a Pi 2B and a Linux PC using iperf. This is pretty close to the theoretical 100 mbps hardware maximum. A Pi should be able to utilize at least half that bandwidth when serving large static pages cached in RAM. However, many websites are moving to https with SSL to preven...
by Jim Manley
Wed Jan 06, 2016 10:52 pm
Forum: General discussion
Topic: Webserver
Replies: 31
Views: 4356

Re: Webserver

Europe is much more densely populated than most of the U.S. Yes, but it's more densely populated than places around here that have excellent network infrastructure: Rank Country 179 United States 182 Estonia 195 Sweden 203 Finland 213 Norway The U.S. is only densely populated on portions of the coa...
by Jim Manley
Wed Jan 06, 2016 8:59 pm
Forum: General discussion
Topic: Raspberry Pi 2 B lifetime or duration before discontinuation
Replies: 9
Views: 1317

Re: Raspberry Pi 2 B lifetime or duration before discontinua

The Model A was upgraded as the improved A+ (more GPIO pins and lower power consumption), albeit with a gap in availability of the A until the A+ could be produced. However, that was in response to slow(ing?) A sales and increasing huge demand for other models, IIRC. If one is accustomed to typical ...
by Jim Manley
Tue Jan 05, 2016 9:44 pm
Forum: General discussion
Topic: Webserver
Replies: 31
Views: 4356

Re: Webserver

Jim, You are right, we see so many unrealistic expectations of the Pi here. From raw CPU performance to network bandwidth. However I'm guessing the Pi might be able to hold 20000 open TCP/IP connections. It might need some careful configuration. There are limits on these things imposed by the kerne...
by Jim Manley
Tue Jan 05, 2016 7:37 pm
Forum: General discussion
Topic: Webserver
Replies: 31
Views: 4356

Re: Webserver

100 Mbps / 20 000 Requests = 5000 bits of data, or 625 bytes per request not accounting for any overheads. I have a Pi 2 colocated in the Netherlands with 100 Mbps upload, which the Pi can fill to about 90 Mbps. For small Projects its absolutely adorable :lol: . The point made by Pithagoros about p...
by Jim Manley
Tue Jan 05, 2016 9:44 am
Forum: General discussion
Topic: Webserver
Replies: 31
Views: 4356

Re: Webserver

I keep having to post this, so my apologies for the redundancy to regular readers, but the point is not getting across - you are _never_ going to see anywhere near the _theoretical_ maximum _instantaneous_ 100 Mbps on a 100Base-T Ethernet port, nor 480 Mbps on any USB 2.0 port, on a Pi or anything e...
by Jim Manley
Tue Jan 05, 2016 8:16 am
Forum: General discussion
Topic: Pi Zero Availability
Replies: 205
Views: 50080

Re: Pi Zero Availability

As I have said before, I think the Zero will always be made is low quantities, simply because there is little or no profit to be made on them. No profit = No Foundation. Not actually the case (although the profit we make is very small) - we're making them as fast as we can. Demand has been...well, ...
by Jim Manley
Tue Jan 05, 2016 5:51 am
Forum: General discussion
Topic: 2 node raspberry pi supercomputer
Replies: 71
Views: 15173

Re: 2 node raspberry pi supercomputer

I can't seem to get >100Mbps out though, despite the virtual ethernet reporting 425Mbps, similar to your usbnet tests. As I've posted elsewhere, you're never going to see anywhere near the full _theoretical_ maximum _instantaneous_ 480 Mbps of USB 2.0 on any system, let alone on a Pi with its const...

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