#qi-hardware IRC log for Sunday, 2011-09-11

Action: kristianpaul biking around00:23
folkz0anybody in here awake i have a serioius hardware question07:01
folkz0server related07:01
wolfspra1lawake yes, but server question, let's see...07:01
folkz0good finally07:02
wolfspra1lwait until you hear "don't know" :-)07:02
wolfspra1lshoot your question...07:02
folkz0ok heres the example say we had 2 xeon dual core processors and 1 desktop core i7 quad core proccesor07:02
folkz0same clock same ram speed etc07:02
folkz0now say we had a program that fully utilizies quad core and all it's features, basically makes use of it07:02
folkz0wouldn't the server system with 2 dual cores perform better then the single quad core07:03
wolfspra1lhypothetical questions, don't we love them...07:03
folkz0a single die cpu with 4 cores would be using up all it's caches within each other07:03
folkz02 seperate die cpu's would have more space07:03
folkz0but then somebody else mentioned the issue about the latency 07:03
wolfspra1lI'd say that depends very much on who designed the board and the many details that make up the eventual performance of your server application07:03
wolfspra1lso the answer is no answer07:04
folkz0the latency shouldn't be that big of a impact07:04
wolfspra1lbest is to try and compare :-)07:04
folkz0thats what i said07:04
folkz0but i mean07:04
folkz0i guess on paper wouldn't the cache07:04
folkz0have effect 07:04
wolfspra1limho you cannot predict how all these things work together07:04
wolfspra1lthat's probably harder than trying your actual load and comparing07:04
folkz0well if anybody can care to jump in07:05
folkz0the latency might be a little higher, but again the design of the board, regardless of that07:05
folkz0wouldn't those extra 2mb caches being split up by 2 cores instead of 407:05
folkz0give some notieable performance or is it no for both statements07:05
wolfspra1lif you have to pick one system and cannot afford to compare with the other one, pick the cheaper one07:05
folkz0i could have sworn i read extra cache helped07:06
folkz0no i'm not buying anything07:06
folkz0i'm trying to prove a dispute07:06
folkz0and this information07:06
folkz0would be beneifical as well07:06
wolfspra1lsounds like :-)07:06
folkz0xeon proccesors can communicate to each other07:07
folkz0i7's can't07:07
wolfspra1lin my experience you cannot easily calculate the performance difference07:07
wolfspra1lbut that's not what you need, you need something to settle the dispute07:07
wolfspra1lbuy a bottle of wine, get drunk, dispute solved07:07
folkz0i get it you dont know07:07
folkz0man anybody awake07:07
folkz0i'm bored07:12
wpwrakwolfspra1l: bah, his problem had a simple answer ;) if the system with more cache is already fully loaded and uses exactly _every_ bit of resources, going to a different system will slow you down :)10:30
wpwrakwolfspra1l: alas, the same is true for the system with less cache, as long as it's better in some other regard (e.g., communication latency)10:31
wpwrakwolfspra1l: thus both lose their bet ... and you get the wine ;-)10:32
wolfspra1lwpwrak: well, of course he dismissed my good faith answer. it's a typical question of people who just pick a fight over something, too little practical problems to take care of :-)11:26
wolfspra1lonce you are down to such details, on any production server, you cannot tell in advance. That's my experience. so pick the cheaper system, and done.11:27
wolfspra1land if it's so important, compare both systems with real load in advance (though that will rarely be economical)11:27
wolfspra1l2 dual core xeon vs. 1 i7 quad, with some cache differences etc. - bah11:29
wolfspra1ltry the load11:29
wolfspra1lthe boards probably designed by two different companies, different chipsets, different memory, etc.11:30
wolfspra1lwhat a question11:30
wolfspra1lreminds me of those card games I played in school, with cars, motorcycles, airplanes etc. where various specs won over each other :-)11:31
wpwrakyeah, of course. the question was nonsensical as asked11:36
wpwrak(card games) ;-))11:36
wpwrakthose were nice. one i remember was with ships. beat a carrier with a speedboat :)11:37
wpwrakroh: by the way, why choose acrylic over polycarbonate ? PC should be lots cheaper than acrylic. is it too brittle ?11:43
wpwrakroh: and another question: can you also "print" something with a laser cutter/engraver ? i.e., not just make a groove, but change the color (e.g., transparent to black)11:47
rjeffriesfree open FPGA tutorial  http://www.xess.com/appnotes/FpgasNowWhatBook.pdf  16:06
rjeffrieshe also has XuLa a $70 USD little FPGA dev board http://www.xess.com/prods/prod048.php16:06
Aylarjeffries: note that there's also the XuLa-50 which is cheaper16:07
rjeffriesAyla cool. is that from the same guy? he makes everything free and open as best I can tell16:08
qi-botThe build has FAILED, see log here: http://fidelio.qi-hardware.com/~xiangfu/compile-log/openwrt-xburst.full_system-09112011-0411/16:08
Aylarjeffries: yes, see http://www.xess.com/prods/prod047.php16:11
wpwrakwolfspra1l: how do you see the possibility of shortening things like http://downloads.qi-hardware.com/people/werner/ at some point in the future ? e.g., dl.qi-hardware.com/p/ ?16:15
wpwrak... /p/werner/, of course16:15
wpwrakalas, i made the mistake of not simply picking "w". that would already have saved 5 characters16:16
wpwraktrimming downloads and people would save 12 characters16:17
wpwrakof course, URLs into git are still much worse ...16:18
kristianpauli think there is already a qi-hw.com16:25
wpwrakyes, but i don't think it does anything. at least i haven't found any useful url so far that wouldn't fail if changing qi-hardware to qi-hw16:27
wpwrak(i usually check this before complaining, just in case :)16:27
rohwpwrak: i think pc was bad to get and it doesnt cut well with a laser16:32
rohi think it was too 'thermoplastic' ... it melts at much lower temperatures.. ah.. and i cannot cut anything emitting chloride vapour... 16:33
wpwrakroh: ah, i see. odd. pc should be a lot more common than acrylic.16:33
wpwrakopen the window ? ;-)16:33
rohbecause that vapour will not only be bad for me but also the machine. it corrodes the mechanics and is bad for the optics.16:33
wpwrakyeah, the cutter may dislike it a bit. that is, if a significant amount of Cl is actually liberated.16:34
rohi know nobody who puts stuff containing cloride into his cutter16:36
wpwrakso just milling then16:36
rohfor pc? yes.. but actually it depends on what i need to do.16:37
wpwrakactually, are you sure that they add Cl to PC ? i couldn't find any reference16:40
wpwrakor do you mean PVC ?16:40
rohsame game16:41
rohah. could be.. not sure entirely (just awoke from a long night after a long party)16:42
rohanyhow.. pc isnt avail in colors by choice.16:42
wpwraki see Cl only in the maufacturing process, but not in the final product16:42
rohand material costs are not important compared to the machine running cost anyhow16:42
lekernelroh, where did you party? :-)16:48
rohalways a lot of fun if you got a clubmarke and your own 'backstage'16:50
wpwrakinteresting according to wikipedia, PC is more expensive than acrylic. hmm.16:50
roheh whut? funny16:50
wpwrakyeha, i'm not quite sure i belive this just yet :)16:51
rohme neither.. i thought pc is what the coca cola bottles are made from. or was the PET`16:53
wpwrakmay be PET16:54
lekernelah, another one of those berlin clubs that never tell you the price of the entrance in advance. it's only after you've traveled x kilometers to get there that you know. how annoying.16:54
rohits not a club. and the price is different every time16:55
wpwrakhm, accordig to at least one shop, acrylic is indeed a little cheaper than PC: http://acrylicparts.com/lexanprice.html http://acrylicparts.com/acrylicprice.html16:55
lekerneldepending on how you look? :-)16:55
rohno. depending on the group organizing it.16:55
lekernelwell... they put flyers online for each party, why the heck don't they write the price on it?16:56
wpwrakand acrylic can be injection molded, too. excellent. seems that i have a winner :)16:56
rohwell..if i can injection-mold.. i would use abs+pc16:56
rohbecause its 'schlagfest'16:56
lekernelthis seems to be an annoying Berlin specialty...16:57
wpwrakwe'll need that for the death metal edition of M1 ;-)16:57
wpwrakspecs: "must survive impact of fists, boots, musical instruments"16:58
lekernelwpwrak, next version will be probably encased in metal :-)17:00
DocScrutinizerthat's punk17:01
lekernel(next major one)17:01
lekernellike mixing consoles etc.17:01
wpwrakmetal would be nice. a lot more stage-proof :)17:02
wpwrakroh will need a mean laser then, though. or bring the mill back up :)17:02
lekernelI think CNC and a bending machine are more appropriate there17:04
wpwrakDocScrutinizer: hmm, i wonder if any of the wilder styles refrains from smashing their instruments. well, at least they should be relatively safe with ambient and synthpop ;-)17:04
lekernelhow are mixing console enclosures manufactured?17:05
lekernelthey look like bent/drilled metal to me...17:05
wpwraklekernel: benging machines sound interesting. i have no idea about that technology.17:05
DocScrutinizerusually are17:05
DocScrutinizergood ole blacksmith business17:06
wpwrakyeah, ancient17:07
DocScrutinizersimple steel folding machines (err tools) can be found in virtually each steel workshop17:08
DocScrutinizerthen usually you do "pulverbeschichtung" after drilling & folding17:11
wpwrakwhat does that do ?17:12
wpwrakah, coating17:13
qi-bot[commit] Werner Almesberger: labsw/README: described situation with respect to high voltage (master) http://qi-hw.com/p/wernermisc/b2c848117:47
qi-bot[commit] Werner Almesberger: m1rc3/norruption/LOG: latest result (showing failure to reproduce NOR corruption) (master) http://qi-hw.com/p/wernermisc/165d79917:47
qi-bot[commit] Werner Almesberger: labsw/fw/labsw.c: improved debouncing and cleaned up button logic (master) http://qi-hw.com/p/wernermisc/a400f9a17:47
qi-bot[commit] Werner Almesberger: labsw/README: all opto headers need wider spacing for high voltage (master) http://qi-hw.com/p/wernermisc/f9c4bb617:47
qi-bot[commit] Werner Almesberger: labsw/web/: Web-based overview page (master) http://qi-hw.com/p/wernermisc/28cdb8917:50
rohlekernel: mixing consoles etc are usually stamped out metal sheets, then folded and pulverized.. as werner said18:12
rohstamping is much cheaper than milling or drilling18:12
wpwrakthe pulverizing came from joerg18:13
rohah. sorry ;)18:13
wpwraki wonder if we can mill a usable stamp18:13
DocScrutinizerno way18:13
rohwell.. i think so. atleast on our mill. (use hardened steel and active flood cooling) .. but we havent done that yet18:13
rohDocScrutinizer: you should visit us at the congress (we will keep raumfahrtagentur open this year)18:14
DocScrutinizernot sure if I join congress this year18:14
rohalready mounted the first canvas for the beamers, second one will follow soon.18:15
rohmeh. storm (tm) http://www.t-online.de/wetter/info/niederschlagsradar.html18:15
DocScrutinizererr, we're talking about that event between xmas and new year?18:16
DocScrutinizer(storm) here as well18:16
Action: DocScrutinizer runs closing windows18:16
Action: DocScrutinizer away for dinner, hoping to arrive at pub dry18:18
DocScrutinizertoo late :-/18:26
DocScrutinizer51FSCK, that's been the last hour of my DSL modem18:38
DocScrutinizer51the differential current switch and fuses were ok after refenabling them, and TV survived too :-)18:40
DocScrutinizeralive again \o/19:53
DocScrutinizerdang, first time the lightning hit my own house19:53
rohDocScrutinizer: uh. everything ok?20:14
DocScrutinizerhalfway back to normal, both my ears and nerves, and the infra20:15
rohuh. lucky.. usually quite some infra gets fried on real direct hits20:15
DocScrutinizerZyXEL DSL exploded20:15
Action: roh already exchanged complete streets of ntba after only one house got hit20:16
DocScrutinizerhas loose parts inside now20:16
rohheh. propably the overvoltage components *g*20:16
DocScrutinizersome dimmers fried, here as well as some hoses away20:16
rohdsl/landline equipment has often even 'spark-gaps' on the pcb. be sure to take a look if you're nosy20:16
rohyou're insured? or only cheap small stuff?20:17
DocScrutinizerwell, it really stinks and got *very* hot while all LEDs were dead20:17
DocScrutinizerI got no ensurance20:17
DocScrutinizergonna get me dinner now, finally20:18
roh:) have fun. food is good for the nerves *g*20:18
DocScrutinizerthen back to switching from PC driven PPPoE to a proper router setup20:18
DocScrutinizerthanks and o/20:19
DocScrutinizerwell, it's been rather ok, I planned to hit this ZyXEL P660 with a sledgehammer since long20:20
DocScrutinizerand I lured the lightning with my green laser - it *worked* X-P20:20
DocScrutinizer(for those curious: ionizing effects on air need a bit more energy than a 200mW laserpointer can drive)20:22
DocScrutinizerand it hit the house, not my hand with laserpointer ;-)20:22
roh 20:31
DocScrutinizer51sub-elipsis statement?21:37
wpwrakDocScrutinizer: (laser) see, it hit the house because it wasn't powerful enough :)22:01
DocScrutinizeryeah, and it took 20s to ripe, after I stopped beaming up22:13
DocScrutinizeractually I'm not sure it was our house, or the neighbour 20m right or left22:15
wpwrakpretty potent then22:15
DocScrutinizerbut I'm sure the lightning didn't come from where I pointed at with the laser, but rather from the "backside" of our house22:16
DocScrutinizer(potent) it killed a dimmer 60m away across the street22:16
wpwrakwow, you have realtime monitoring of all the dimmers in your street ?22:17
DocScrutinizeronly of those in my fav pubs ;-)22:18
wpwrakso the emergency evacuation procedure is to leave home and go to the pub ? sounds nice :)22:18
DocScrutinizererr, yes :-D22:18
DocScrutinizergiven the fact I was about to leave for dinner when I posted [2011-09-11 20:26:01] <DocScrutinizer> too late :-/22:20
DocScrutinizersome 5..10min later lightning stroke, so I thought it's be best to finally get dinner after I checked there's no hidden fires anywhere in the house22:21
DocScrutinizerhmm, NFC what blew up in this POS ZyXEL22:29
DocScrutinizerBWAHAHAHA red water from the tap22:33
DocScrutinizerseems the lightning properly cleaned all the rust out of the tubing22:33
DocScrutinizerI already wondered which obscure path the lightning took from our 150yo house's roof down to the ground22:35
DocScrutinizerseems now I got a clue22:35
wpwraknice clean water ... soon :)22:40
DocScrutinizernow for the tedious d-link config22:41
Action: DocScrutinizer wonders if it might be simpler to access the config webpage of dlink router via WLAN rather than via a temporary set up wiring and network IP addr22:42
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