Really, it is stylish (nice color, will look good on coffee table), it runs UNIX, can be gotten for cheap now, even included an IndyCam -- and form-factor is not too far from mini-mac.
Do not get me wrong, Cray-4 would be a technological marvel, as all the previous ones (I've had a chance to see one of its boards once!;-) ).
but much of that was due to aggressive circuit-board designs that led to problems with open contacts, and the difficulty of repairing them
But did not it have at least something to do with 1) low level of integration of the chips, thus need for more wiring on the board and 2) necessity to take all that frigging heat off safely.
The failure of Cray Computer was due to competition and missing market windows
The end of Cold War did not help much either...
btw, the 10th anniversary of the CCC bankruptcy is coming up on March 24th. My, how the years fly by sometimes
I second that!
Paul B.
Re:GaAs??? GaAs is material of the future...
on
Where's My 10 Ghz PC?
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· Score: 2, Informative
STI and Conductus were successful in marketing PASSIVE HTS components (analog filters for cellular basestation receivers) and their main accomplishment was, actually, making "normal" systems engineers not to be scared of having a cooler in the system (providing a reliable cooler was also important;-) ). The brilliant marketing gimmick was that they actually packaged a traditional filter and a switch in parallel with their SC filter in the same box, so if the cooler would fail the system would fall back to the traditional normal design, with some loss of capacity, of course, but at least it would still function.
As to digital logic, it is REALLY hard to make reproducible Josephson jucntions (active elements in SCE circuits) in HTS. One can make 2-4 of them for SQUID sensors (and it is a bit market for HTS too), but for digital stuff you need thousands and millions of them. In certain way HTS vs. LTS is similar to GaAs vs. CMOS -- it is easy to make a really nice, but simple, analog front-end in one, but the other can handle much more processing.
Replacing metal wiring on transistor chips with superconductor wiring will not help that much, yes, part of the RC constant which takes care of wire resistance, will be gone, but you'd still dissipate F*CV^2/2 power to charge/discharge the line. To fully utilize SCE logic one needs to use SCE active elements (current-sensitive JJs, not voltage-sensitive transistors).
I forsee the day that a user will be able to use a superconducting set of electronics on the desk.
Me too!;-) It definitely can be done IF some larger system is built and verified first, then technology becomes a commodity. Check out, for example, this presentation by my former advisor and one of the godfathers of the whole field, seach for PeT workstation...;-)
Paul B.
P.S. There is another fundamental reason to chose LTS, rather than HTS superconductors. The beauty of SFQ logic is that it uses almost quantum-limited amount of energy per switch. When one starts increasing temperature, thermal noise becomes too high (yes, even at 77K) and the main advantage -- tiny energy dissipation, which allows for very dense packaging -- goes away.
OK, I surely know John Clarke, but for my like I was trying to steer clear from analog SQUIDs, pushing for digital stuff.
Paul B.
Re:GaAs??? GaAs is material of the future...
on
Where's My 10 Ghz PC?
·
· Score: 2, Informative
I haven't been in the superconducter field for ten years now... what's the technology being used for the switches/logic gates?
Hmm, I am wondering what kind of logic were you using 10 years ago!;-) Good old latching stuff? No, it was 1994, SFQ and Nb triulayer was already out there in the field, actually I did come to this country to work on it some time in '92, I guess...
Yes, it is SFQ/RSFQ (Single Flux Quantum) logic, counting individual magnetic flux quanta, but no, it has nothing to do with now over-financed "quantum computing".;-) We can put tens of thousands Josephson junctions per chip now, all connected with matched superconductor transmission line (i.e., no RC time constants, nor F*CV^2/2 power), though which picosecond-wide pulse fly just fine. If you are interested, I can tell A LOT more -- hey, I'm one of the people who are still interested in pursuing this technology...
As for GaAs, it's alive and well in the world of RF (analog) amplifiers going up to 100 GHz
And with InP you can go to 150 GHz and maybe higher amplifiers (though not broadband), but there is a huge difference between being able to amplify a signal and being able to do any kind of meaningful digital logic at fixed power consumption... Actually, time for me to get off/. and get back to those pesky transistors...;-)
I was not talking about the consumer market here (yes, I understand that the original poster wanted a 10 GHz processor under his desk, but I did not had that in mind). What consumers really want is a nice thin client in there, hmm, cellphone with a laser projected image directly on there retina and lots of bandwidth and computational power upstream.
People who provide THAT power and bandwidth CAN afford whatever cooling is needed if they can get more bang per buck. My favorite SCE project was to allow telcos to replace 5 racks of routers with one rack, half of that densily packed SCE, half cooler compressor and electronics, same number of lines, all running at 60 GHz rather than 10...
And yes, you need LHe cooling for this stuff, but you would be surprized at how advanced modern pulse-tube coolers are. Without disclosing anything that I am not supposed to disclose;-), check out this NASA presentation about space-qualified coolers: here, if this would become any kind of a mass market a cooler like this would cost a couple thousand $$, maybe a bit too costly for your home, but definitely affordable for telco/service provider market.
Not only that, but you look at the power dissipated by 20 transistors (actually if it is, say, InP, you can talk about 100 transistors) and multiply it by the number required to build a CPU...;-) You do not want to dissipate (and somehow take off the chip) a megawatt per CPU even in the supercomputer box, not to mention anything smaller than that!
Paul B.
GaAs??? GaAs is material of the future...
on
Where's My 10 Ghz PC?
·
· Score: 4, Interesting
... and will always be!;-) I think I first read this qoute sometimes in late 80s/early 90s, and it is still true. You know why? Ever looked at power dissipation specks of even the simplest GaAs chips? You would not want to build a processor out of those, Cray tried with Cray 4 and failed...;-(
superconductors is the way to go for highest speeds/most concentrated processing power, due to extremely small power dissipation and extremely high clock frequencies (60 GHz for logic is relatively easy right now), but the problem is that after someone invests $3B in a modern semiconductor fab they do NOT want to build a $30M top-of the line superconductor fab to compete with it. IBM would be a good candidate for this, but they got burned on superconductor computer project back in 80s and would not touch it with 10 foot pole now, though both logic and fab has changed dramatically since then.
Disclosure: on my day job I do design III-V chips, and I used to design superconductor chips up until recently, now trying to push that technology forward is more of a night job for me...;-)
I would think that that was the case (and of course, I'd love to be able to chat with the guy while he was doing it, but I was not there). My wife account is that she mentioned that she brought it from US and her husband (me) says that something has to be done to it to make it work, the guy said "Do not worry, let me have it now...", took it, popped it open, maybe did something else, popped in the new SIM card and it just worked from that point on. So no resoldering, not even connecting any dongles -- maybe just some key combination was pressed. The phone works just fine with the original SIM over here as well.
It's expensive to get a phone that's "unlocked" (doesn't refuse SIMs from operators other than the network that sold the phone), but it's not impossibly so.
Me and my wife bought our phones from Cingular because we wanted to use them abroad and GSM seems to be the most universally accepted. OK, so she was planning her trip to Russia and I called Cingular to unlock the phone -- no luck, "your contract is not over yet, can not do". Anyway, she takes the phone with her, goes into one of the SIM card vendors on a street corner in Moscow, he puts SIM in (maybe doing something else in the process;-) ) -- and everything works like charm!
Did he actually know how to unlock it or were we lucky or was the phone not locked from the beginning? Who knows...
A rifle bullet will have a velocity that's a relatively small multiple of the airliner's velocity.
You know alot about bullets and rifles, right?;-)
Actually a bullet fired from a good rifle is supersonic, compare to Mach 1.
What was the last time you flew on a supersonic aircraft?
The real difference is that the beam from that kind of laser is continuos, so it works both as a "spot mark" AND as a "bullet", with an infinite number of rounds per minute.
Damn, no mod points again, when I want to use those...
From what I know, the total Federal Dept. of Education's budget is about twice the total defence budget (I remember numbers of $B800 vs. $B400 from a couple of years ago, not sure what they are now), while education is not even one of the constitutionally-authorized duties of the Federal Govt! Not that I am saying that it is BAD, only that maybe, just maybe, it would be better left to the states, counties, towns, etc....
And on top of that _graduate_ _computer_ _science_ students in a decent (in CS) University do not have a clue what log() is, really...
To say that the current version of the Company X product is so much better than the previous version of the _same company's_ product does not really endorse _either_ version.
if it not a troll, it is a great story !!! (and I feel good about not being able to distinguish one from another, but I can actually imagine it to be true!;-) )
Just a serious Q for someone with 5-digit UID -- really, do you think Maple gets anywhere near Mathematica in symbolic capabilities? last time I checked a couple of yours ago I was still inclined to go with "the crazy Steve"'s creation...;-)
Not to mention the fact that I personally was friends with two real theoretical physicists (one in high energey, another one in solid state), and they BOTH had their favorite "integrals that Mathematica can not do symbolically", but them were extremely bright guys and they did spend time searching for the "wrong" one. _I_ myself encountered ones that Maple could not do in the course of day-to-day engineering work...;-)
How do you calculate or code something that has triple integrals in it?
usually, the case which requires triple integration is much easier to be thought of as 'integration over VOLUME", which can be converted to something else...
I (after getting my M.S. in Physics in "Soviet Russia" -- literally -- and my M.S. in CS in the good old U.S.ofA.) was quite shocked to read rather recently that in the original Maxwell's equations there were, like, 21 of them -- one for each spatial direction, I guess... the ones I remember are 4, and the one I vaguely remember is just one (the relativistic one, with a square symbol instead of the upside-down triangle for nabla...;-) ).
In 1 ns (1GHz) light travels roughly a foot (1/3 of a meter) in air or low-Er coax. In 0.3 ns (3 GHz) it's 10 cm -- see, an order or magnitude!;-)
But as I pointed out couple postings above and what teh GP I think had in mind was not speed-of-light limited communication latency, but RC delays of (non-matched) metal wires.
And it does not really matter how fast electrones move on the wire (though it matters inside transistor gate) -- you are limited either by speed of light propagation in matched line OR the time it takes to charge C through R to threshold voltage V.
But still even for small blocks (like your 16 bit adder) where lines are relatively short, charging and discharging of gate capacitance (expecially for modern thin gates) is another limiting factor in both speed (RC) and power (F*CV^2/2).
A related thing (that I personally worked on for many years) is how do you build general-purpose computing logic where you connect gates not with your standard "wires" but with real (matched) transmission lines. Belive me, it is not a trivial task, even if you have an ideal transmission lines (i.e., superconducting) and your active devices can operate at hundreds of GHz, you STILL get your "clock frequency" in the order of several 10s of GHz for small blocks, not hundreds.
Conventional processor speed it determined by the RC constants of its longest nets, not that much by the transistor speed. Your average FET can amplify signals in ~10 GHz range, and a bipolar -- GaAs, InP, SiGe -- transistor works just fine up to almost a 100 GHz, but it does NOT translate into digital processing clock speed much above 4 GHz, all due to wiring and its RC.
But you have raw materials inside you already!
on
HIV Vaccine
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· Score: 3, Interesting
... now all you need is a "machine" to combine them! Think about the possibility of a drug which, after injected, ties itself to the dendritic cells and starts hunting in your blood for dead viruses, then replaces itself with the dead virus body -- hey, you've just produced a vaccine!
The bottom line is that now that the positive effect is demonstrated, the next step is to find out the cost-effective way to combine cells and dead viruses, preferrably in-viro. Let's hope that someone will manage to do it!
Slashdot Mirror
ARe you sure you mean Indy and not Challenge? As far as I remember, Indys did run quite cool, ar least R4000 series.
Paul B.
Really, it is stylish (nice color, will look good on coffee table), it runs UNIX, can be gotten for cheap now, even included an IndyCam -- and form-factor is not too far from mini-mac.
Only partially kidding!
Paul B.
You would thing Firefox would include a speller checker!
;-)
Oh, well...
Paul B.
Current level of taxation, maybe? So that for most of the middle class families it takes both parents to work to provide for the kids?
Look up what the tax rate was in those days, I read that it was somewhere in single digits (can not find the link now).
Now 1/3 to 1/2 of your paycheck is deducted...
Paul
Do not get me wrong, Cray-4 would be a technological marvel, as all the previous ones (I've had a chance to see one of its boards once! ;-) ).
but much of that was due to aggressive circuit-board designs that led to problems with open contacts, and the difficulty of repairing them
But did not it have at least something to do with 1) low level of integration of the chips, thus need for more wiring on the board and 2) necessity to take all that frigging heat off safely.
The failure of Cray Computer was due to competition and missing market windows
The end of Cold War did not help much either...
btw, the 10th anniversary of the CCC bankruptcy is coming up on March 24th. My, how the years fly by sometimes
I second that!
Paul B.
STI and Conductus were successful in marketing PASSIVE HTS components (analog filters for cellular basestation receivers) and their main accomplishment was, actually, making "normal" systems engineers not to be scared of having a cooler in the system (providing a reliable cooler was also important ;-) ). The brilliant marketing gimmick was that they actually packaged a traditional filter and a switch in parallel with their SC filter in the same box, so if the cooler would fail the system would fall back to the traditional normal design, with some loss of capacity, of course, but at least it would still function.
;-) It definitely can be done IF some larger system is built and verified first, then technology becomes a commodity. Check out, for example, this presentation by my former advisor and one of the godfathers of the whole field, seach for PeT workstation... ;-)
As to digital logic, it is REALLY hard to make reproducible Josephson jucntions (active elements in SCE circuits) in HTS. One can make 2-4 of them for SQUID sensors (and it is a bit market for HTS too), but for digital stuff you need thousands and millions of them. In certain way HTS vs. LTS is similar to GaAs vs. CMOS -- it is easy to make a really nice, but simple, analog front-end in one, but the other can handle much more processing.
Replacing metal wiring on transistor chips with superconductor wiring will not help that much, yes, part of the RC constant which takes care of wire resistance, will be gone, but you'd still dissipate F*CV^2/2 power to charge/discharge the line. To fully utilize SCE logic one needs to use SCE active elements (current-sensitive JJs, not voltage-sensitive transistors).
I forsee the day that a user will be able to use a superconducting set of electronics on the desk.
Me too!
Paul B.
P.S. There is another fundamental reason to chose LTS, rather than HTS superconductors. The beauty of SFQ logic is that it uses almost quantum-limited amount of energy per switch. When one starts increasing temperature, thermal noise becomes too high (yes, even at 77K) and the main advantage -- tiny energy dissipation, which allows for very dense packaging -- goes away.
OK, I surely know John Clarke, but for my like I was trying to steer clear from analog SQUIDs, pushing for digital stuff.
Paul B.
I haven't been in the superconducter field for ten years now... what's the technology being used for the switches/logic gates?
;-) Good old latching stuff? No, it was 1994, SFQ and Nb triulayer was already out there in the field, actually I did come to this country to work on it some time in '92, I guess...
;-) We can put tens of thousands Josephson junctions per chip now, all connected with matched superconductor transmission line (i.e., no RC time constants, nor F*CV^2/2 power), though which picosecond-wide pulse fly just fine. If you are interested, I can tell A LOT more -- hey, I'm one of the people who are still interested in pursuing this technology...
/. and get back to those pesky transistors... ;-)
Hmm, I am wondering what kind of logic were you using 10 years ago!
Yes, it is SFQ/RSFQ (Single Flux Quantum) logic, counting individual magnetic flux quanta, but no, it has nothing to do with now over-financed "quantum computing".
As for GaAs, it's alive and well in the world of RF (analog) amplifiers going up to 100 GHz
And with InP you can go to 150 GHz and maybe higher amplifiers (though not broadband), but there is a huge difference between being able to amplify a signal and being able to do any kind of meaningful digital logic at fixed power consumption... Actually, time for me to get off
Paul B.
I was not talking about consumer electronics, see my reply a couple of posts up...
Paul B.
I was not talking about the consumer market here (yes, I understand that the original poster wanted a 10 GHz processor under his desk, but I did not had that in mind). What consumers really want is a nice thin client in there, hmm, cellphone with a laser projected image directly on there retina and lots of bandwidth and computational power upstream.
;-), check out this NASA presentation about space-qualified coolers: here,
People who provide THAT power and bandwidth CAN afford whatever cooling is needed if they can get more bang per buck. My favorite SCE project was to allow telcos to replace 5 racks of routers with one rack, half of that densily packed SCE, half cooler compressor and electronics, same number of lines, all running at 60 GHz rather than 10...
And yes, you need LHe cooling for this stuff, but you would be surprized at how advanced modern pulse-tube coolers are. Without disclosing anything that I am not supposed to disclose
if this would become any kind of a mass market a cooler like this would cost a couple thousand $$, maybe a bit too costly for your home, but definitely affordable for telco/service provider market.
Paul B.
Not only that, but you look at the power dissipated by 20 transistors (actually if it is, say, InP, you can talk about 100 transistors) and multiply it by the number required to build a CPU... ;-) You do not want to dissipate (and somehow take off the chip) a megawatt per CPU even in the supercomputer box, not to mention anything smaller than that!
Paul B.
... and will always be! ;-) I think I first read this qoute sometimes in late 80s/early 90s, and it is still true. You know why? Ever looked at power dissipation specks of even the simplest GaAs chips? You would not want to build a processor out of those, Cray tried with Cray 4 and failed... ;-(
;-)
superconductors is the way to go for highest speeds/most concentrated processing power, due to extremely small power dissipation and extremely high clock frequencies (60 GHz for logic is relatively easy right now), but the problem is that after someone invests $3B in a modern semiconductor fab they do NOT want to build a $30M top-of the line superconductor fab to compete with it. IBM would be a good candidate for this, but they got burned on superconductor computer project back in 80s and would not touch it with 10 foot pole now, though both logic and fab has changed dramatically since then.
Disclosure: on my day job I do design III-V chips, and I used to design superconductor chips up until recently, now trying to push that technology forward is more of a night job for me...
Paul B.
I would think that that was the case (and of course, I'd love to be able to chat with the guy while he was doing it, but I was not there). My wife account is that she mentioned that she brought it from US and her husband (me) says that something has to be done to it to make it work, the guy said "Do not worry, let me have it now...", took it, popped it open, maybe did something else, popped in the new SIM card and it just worked from that point on. So no resoldering, not even connecting any dongles -- maybe just some key combination was pressed. The phone works just fine with the original SIM over here as well.
Paul B.
It's expensive to get a phone that's "unlocked" (doesn't refuse SIMs from operators other than the network that sold the phone), but it's not impossibly so.
;-) ) -- and everything works like charm!
Me and my wife bought our phones from Cingular because we wanted to use them abroad and GSM seems to be the most universally accepted. OK, so she was planning her trip to Russia and I called Cingular to unlock the phone -- no luck, "your contract is not over yet, can not do". Anyway, she takes the phone with her, goes into one of the SIM card vendors on a street corner in Moscow, he puts SIM in (maybe doing something else in the process
Did he actually know how to unlock it or were we lucky or was the phone not locked from the beginning? Who knows...
Paul B.
A rifle bullet will have a velocity that's a relatively small multiple of the airliner's velocity.
;-)
You know alot about bullets and rifles, right?
Actually a bullet fired from a good rifle is supersonic, compare to
Mach 1.
What was the last time you flew on a supersonic aircraft?
The real difference is that the beam from that kind of laser is continuos, so it works both as a "spot mark" AND as a "bullet", with an infinite number of rounds per minute.
Paul B.
Damn, no mod points again, when I want to use those...
From what I know, the total Federal Dept. of Education's budget is about twice the total defence budget (I remember numbers of $B800 vs. $B400 from a couple of years ago, not sure what they are now), while education is not even one of the constitutionally-authorized duties of the Federal Govt! Not that I am saying that it is BAD, only that maybe, just maybe, it would be better left to the states, counties, towns, etc....
And on top of that _graduate_ _computer_ _science_ students in a decent (in CS) University do not have a clue what log() is, really...
Paul B.
Or something else... really...
To say that the current version of the Company X product is so much better than the previous version of the _same company's_ product does not really endorse _either_ version.
Paul B.
if it not a troll, it is a great story !!! (and I feel good about not being able to distinguish one from another, but I can actually imagine it to be true! ;-) )
Paul B.
Just a serious Q for someone with 5-digit UID -- really, do you think Maple gets anywhere near Mathematica in symbolic capabilities? last time I checked a couple of yours ago I was still inclined to go with "the crazy Steve"'s creation... ;-)
;-)
Not to mention the fact that I personally was friends with two real theoretical physicists (one in high energey, another one in solid state), and they BOTH had their favorite "integrals that Mathematica can not do symbolically", but them were extremely bright guys and they did spend time searching for the "wrong" one. _I_ myself encountered ones that Maple could not do in the course of day-to-day engineering work...
How do you calculate or code something that has triple integrals in it?
... ;-) ).
usually, the case which requires triple integration is much easier to be thought of as 'integration over VOLUME", which can be converted to something else...
I (after getting my M.S. in Physics in "Soviet Russia" -- literally -- and my M.S. in CS in the good old U.S.ofA.) was quite shocked to read rather recently that in the original Maxwell's equations there were, like, 21 of them -- one for each spatial direction, I guess... the ones I remember are 4, and the one I vaguely remember is just one (the relativistic one, with a square symbol instead of the upside-down triangle for nabla
Paul B.
... your numbers are the other way around!
;-)
In 1 ns (1GHz) light travels roughly a foot (1/3 of a meter) in air or low-Er coax. In 0.3 ns (3 GHz) it's 10 cm -- see, an order or magnitude!
But as I pointed out couple postings above and what teh GP I think had in mind was not speed-of-light limited communication latency, but RC delays of (non-matched) metal wires.
And it does not really matter how fast electrones move on the wire (though it matters inside transistor gate) -- you are limited either by speed of light propagation in matched line OR the time it takes to charge C through R to threshold voltage V.
Paul B.
But still even for small blocks (like your 16 bit adder) where lines are relatively short, charging and discharging of gate capacitance (expecially for modern thin gates) is another limiting factor in both speed (RC) and power (F*CV^2/2).
A related thing (that I personally worked on for many years) is how do you build general-purpose computing logic where you connect gates not with your standard "wires" but with real (matched) transmission lines. Belive me, it is not a trivial task, even if you have an ideal transmission lines (i.e., superconducting) and your active devices can operate at hundreds of GHz, you STILL get your "clock frequency" in the order of several 10s of GHz for small blocks, not hundreds.
Paul B.
Conventional processor speed it determined by the RC constants of its longest nets, not that much by the transistor speed. Your average FET can amplify signals in ~10 GHz range, and a bipolar -- GaAs, InP, SiGe -- transistor works just fine up to almost a 100 GHz, but it does NOT translate into digital processing clock speed much above 4 GHz, all due to wiring and its RC.
Paul B.
And almost did, but you beat me to that...
Paul
... now all you need is a "machine" to combine them! Think about the possibility of a drug which, after injected, ties itself to the dendritic cells and starts hunting in your blood for dead viruses, then replaces itself with the dead virus body -- hey, you've just produced a vaccine!
The bottom line is that now that the positive effect is demonstrated, the next step is to find out the cost-effective way to combine cells and dead viruses, preferrably in-viro. Let's hope that someone will manage to do it!
Paul B.