lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) (07/27/90)
I just got some literature from Velox (in Santa Clara) about a product they call an ICECAP. It turns out to be a box, some inches deep, which uses a solid state technology to cool a chip to zero degrees Celcius. Peltier-effect refrigeration has been known since 1838, so the technology is believable. It's intrinsically inefficient: one puts 3 to 6 watts into the box for each watt that one wants transferred from the chip to the heat sink. The literature claims that they've used it to run an 80486 at 50 MHz. Does anyone know if this is a reasonable claim? -- Don D.C.Lindsay
zik@bruce.cs.monash.OZ.AU (Michael Saleeba) (07/27/90)
In <10022@pt.cs.cmu.edu> lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) writes: >I just got some literature from Velox (in Santa Clara) about a >product they call an ICECAP. >... >The literature claims that they've used it to run an 80486 at 50 MHz. >Does anyone know if this is a reasonable claim? Peltier effect semiconductor cooling devices have been advertised in trade journals for quite a few years (at least on Oz). I particularly remember one such ad which had the IC under cooling _totally_covered_in_frost! +-------------------------------+------------------------------------+ | Michael Saleeba | "The second law of Thermodynamics | | zik@bruce.cs.monash.oz | is the ultimate restatement of | | -|- Zik -|- | Murphy's law." | +-------------------------------+------------------------------------+
davidb@brac.inmos.co.uk (David Boreham) (07/27/90)
In article <10022@pt.cs.cmu.edu> lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) writes: > >I just got some literature from Velox (in Santa Clara) about a >product they call an ICECAP. > >It turns out to be a box, some inches deep, which uses a solid state >technology to cool a chip to zero degrees Celcius. Peltier-effect >refrigeration has been known since 1838, so the technology is >believable. It's intrinsically inefficient: one puts 3 to 6 watts >into the box for each watt that one wants transferred from the chip >to the heat sink. > >The literature claims that they've used it to run an 80486 at 50 MHz. >Does anyone know if this is a reasonable claim? >Don D.C.Lindsay Yes, sounds reasonable. 1) Peltier heat-pumps are used commonly to cool down various hot bits of electronics such as laser diodes in optical fiber systems. As long as you've got somewhere to dump the heat, then they work quite well. The datasheets I have go up to a unit offering 68.8W of pumping and a max temp differential of 65 degrees C. That is 40 by 40 milimeters, which is about the size of a 486 package. 2) CMOS devices like the 486 will definitely run faster if cooler. It's common to find vendors shipping samples of fast parts with ``relaxed temp spec'' for instance, because they really don't have a fast enough part. A couple of years ago someone was rumoured to have an IMST414 running at 50MHz in liquid N :) The trouble with this kind of dodge is that nobody is going to trust the thing to work under all conditions. It is not the case that all the ``speed related'' characteristics of the device track temperature in the same way. So, you are going to be requiring a VLSI tester and intel's test programs to test devices at zero C and speed bin. Then you're going to to have to do some kind of qualification testing to ensure that the asumptions made in the testing still hold when the maximum clock speed is used at low temperature. You would also need to do a fair amount of thermal work on the packaged assembly to find out what the die temperature varies between given an ambient temp range and different device dissipation figures. So, yes it is realistic but only really if you can do a large amount of re-testing and qualification or if you can persuade Intel to ship parts tested for 50MHz operation with a heat-pump. BTW these pumps cost about $50, what are these guys charging for their unit ? David Boreham, INMOS Limited | mail(uk): davidb@inmos.co.uk or ukc!inmos!davidb Bristol, England | (us): uunet!inmos.com!davidb +44 454 616616 ex 547 | Internet: davidb@inmos.com
bruner@sp15.csrd.uiuc.edu (John Bruner) (07/27/90)
Could someone provide a reference to a description of Peltier coolers (the physics involved, not the available commercial products)? -- John Bruner Center for Supercomputing R&D, University of Illinois bruner@csrd.uiuc.edu (217) 244-4476
msp33327@uxa.cso.uiuc.edu (Michael S. Pereckas) (07/28/90)
These devices are also used to cool film or CCDs in telescopes. -- Michael Pereckas * InterNet: m-pereckas@uiuc.edu * just another student... (CI$: 72311,3246) *Jargon Dept.: Decoupled Architecture--sounds like the aftermath of a tornado*
mark@parc.xerox.com (Mark Weiser) (07/28/90)
Could someone provide references to further information about Peltier collers (the commercial products, not the physics involved)? -mark -- Spoken: Mark Weiser ARPA: weiser@xerox.com Phone: +1-415-494-4406