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I won a science fair when I was a kid doing this with a 286; it worked great except for all of the condensation :D
by jdenning 2y ago
I won a science fair when I was a kid doing this with a 286; it worked great except for all of the condensation :D
- ant6n 2y agoA 3600 MHz 286?! Clearly you jest.
- redundantly 2y agoYo, Imma need you to provide more details, this sounds super awesome! Do you perhaps have any pictures or the original paper for your project?
- jdenning 2y agoIt really wasn’t that fancy, I didn’t even measure the clock speed - just wrote a little program (I think it was in QBasic) that calculated factorials or something (don’t remember the details), then measured performance difference between no cooling, ice water, and liquid nitrogen. Made some graphs, printed with my color inkjet (very fancy at the time). It was more a situation of being a computer nerd at exactly the right time and place so that it was possible to really impress adults with minimal actual effort
- redundantly 2y agoDude, that's cool! Now I have to look around if someone has anything similar. I was always trying to find ways to improve the performance of my systems when I was a kid. Tweaking configs, removing bloat, stealing components from my parents systems. I would've loved to have tried what you did!
- eru 2y agoHow did you get your hands at liquid nitrogen as a kid?
- colechristensen 2y agoYou can just buy it at the appropriate gas supplier, my local university used to sell it. If your parent was a nerd or a welder it would be fairly easy, it can just be expensive getting an appropriately sized dewar if a thermos isn’t big enough for your usage (or if you can’t find someone willing to sell you only a thermosful, which is admittedly a little dangerous)
- jdenning 2y agoThis is exactly correct. The nerd/hacker acorn doesn’t fall far from the nerd/hacker tree. Same reason I had a spare 286 lying around
- sitkack 2y agoMy physics department had a spigot coming out the wall and sheet with the number of liters you poured yourself. It was about the price of milk.
- Y_Y 2y agoMy university was the only place in my city that had a plant for liquid nitrogen so they supplied all the hospitals. They also were pretty cool about giving it out, so you could do diy ice cream or minor cosmetic procedures.
- jdenning 2y agoMy dad got it just to play with on a couple of occasions. We froze and reanimated brine shrimp once..blew up a 2 liter bottle (do not attempt - it was really loud). He just got it from a gas supply - I’m sure it’s the same situation today. The liquid nitrogen itself is fairly inexpensive, but you need to rent a special container for it.
- tastyfreeze 2y agoDewar flask is the container. Hospitals also have liquid gasses but don't usually sell it directly.
- ben_w 2y ago> It was more a situation of being a computer nerd at exactly the right time and place so that it was possible to really impress adults with minimal actual effort Oh, I know that feeling. Blew one teacher's mind by doing animations on the RISC OS machines at school, they didn't know it was even possible. 4D-maze visualisation and route-finding at university. What was weird was all the times I've shown people Word Lens or Google Translate, augmented reality translations blew the minds of other developers even a decade after that was demonstrated. Right time and place.
- mrguyorama 2y agoHow did this work? 286 didn't have free clock scaling. Cooling it could make it use less power I guess, by lowering internal resistances, but that won't make it run faster, it's still running based on the clock rate. More importantly, a hot CPU wouldn't perform worse, it would just break at some point when a computation got the wrong result.
- remlov 2y agoHow did this work? By swapping crystal oscillators with a higher frequency.
- alsetmusic 2y agoAnd just yesterday, I was remembering a 6th grade science experiment that involved a radar gun that my father "borrowed" from a police dept (I suspect he paid to borrow or bought it outright and didn't tell me) and how that was somewhat sophisticated compared to the projects of other kids. Really put me in my place with this one. Nice work.
- mrguyorama 2y agoOlder CPUs didn't have a range of performance. They either worked at a clock speed, or didn't. If you put in a very high rate crystal, the CPU would either work at that higher rate without cooling, or not work without cooling. Clock speed was a constant. >I didn’t even measure the clock speed - just wrote a little program (I think it was in QBasic) that calculated factorials or something (don’t remember the details), then measured performance difference between no cooling, ice water, and liquid nitrogen. >My measurement technique was extremely simplistic - how much wall clock time does it take to do this computationally-intensive task. It ran faster with ice water, and even faster with the liquid nitrogen (until it died from condensation). There is no world in which a 286 has a program that runs "slow" without cooling, and fast with cooling. If a clock speed "needs cooling", it's because the CPU crashes otherwise. If jdenning changed the crystal, THAT'S what increased the CPU speed. They seem adamant that wasn't the case though.
- deleted 2y ago[deleted]
- gosub100 2y agoSo you thought of this idea yourself at that age?
- jdenning 2y agoI mean, my dad had already got liquid nitrogen for us to play with on a few occasions, I think he suggested “something with liquid nitrogen would be science fair gold”..it doesn’t take very deep knowledge to understand that cooler is better for a cpu.
- emptiestplace 2y agoApparently it takes a bit to understand that CPU temperature doesn't affect clock speed, though!
- jdenning 2y agoMy measurement technique was extremely simplistic - how much wall clock time does it take to do this computationally-intensive task. It ran faster with ice water, and even faster with the liquid nitrogen (until it died from condensation). I truly don’t understand why this anecdote seems to be offensive - but let me assure you, I’m claiming no scientific discovery or prodigious understanding of cpus here. It was neat - computers, liquid nitrogen, color charts.. in the early 90s. That kind of shit got you scholarships back in the day.
- northwest65 2y agoI think it's because CPUs don't run faster just because they're colder, they run faster when you overclock them. Often to get them stable at higher clock speeds you need more voltage, which at some point demands more cooling to mitigate that. AFAICT doing interesting but ultimately trivially complicated stuff as a youngster can still result in scholarships etc, Ahmed Mohamed comes to mind.
- jdenning 2y ago
- magicalhippo 2y agoMy 286 was nominal 8 MHz, but the red turbo button boosted that to 12 MHz. How far did you manage to push it?
- daqnz 2y agoThe turbo button actually was used to underclock the CPU's speed, not increase it. https://en.wikipedia.org/wiki/Turbo_button https://en.wikipedia.org/wiki/Turbo_button
- zeagle 2y agoThe linked article suggests it could be both ways for button behavior. But I see what you mean for how it achieves it.
- seritools 2y agoYup, on many boards you could either jumper the direction (turbo switch closed= slow or closed = fast), or set it in the BIOS.
- deaddodo 2y agoIt could work either way. It would be better to phrase it as "outside of turbo mode it operated as a 4mhz 8086, with turbo it operated faster (usually the CPU's actual rated speed)".
- _nalply 2y agoHah that reminds me of the way of a supermarket chain to shill rebates. Turbo button not pressed, run at lower speed than rated Turbo button pressed, run at rated speed No rebate, sell at a huge margin Rebate, sell at a minimum margin
- copperx 2y agoHow did you overclock it??????
- burnte 2y agoYou replace the crystal on the motherboard with a faster one. I did it on 386s and 486s. Adrian Black recently did it with a 286 too I think.
- fortran77 2y ago286 systems generally didn’t have programmable on-chip clock oscillators for the CPU. There was an external clock chip that generated the exact frequency needed for the CPU; sometimes there was another setting for a reduced speed for compatibility. If you changed this clock, you’d also disturb all the other I/O that depended on it. I can see why you won! In the early 80s, just building the clock circuitry to generate arbitrary frequencies for the CPU only would have been quite an engineering feat.
- rodneyknaap 2y agoI have one possible explanation for such a phenomena to happen that cooling might make a 286 run faster. What may have been happening is that cooling the CPU shifted the timing of the CPU which is very plausible, this may have affected the system control circuits that terminate the cycles if something was right over the margin of timing. In some cases a slight shift in timing may advance the terminated T_COMMAND of the 286 into one CPU clock cycle earlier. That could theoretically result in a significant faster performance. Imagine one T_STATUS and for example three T_COMMAND cycles, a total of 4 CPU cycles that were executed previously, shifting into one T_COMMAND earlier, this would result in 1 T_STATUS and 2 T_COMMAND cycles, and increase the efficiency of the CPU by 25%.
- FatalLogic 2y agoWhat are "T_COMMAND" and "T_STATUS"? I searched but that terminology doesn't seem to be used much
- rodneyknaap 2y agoThose are states of the 286. This is described in the Intel 286 documentation for system engineers.
- FatalLogic 2y agoThanks for your reply
- deleted 2y ago[deleted]