IIRC, the chip technology of that era produced a lot of heat in very small places and was very temperature sensitive. There were things called TCM's or Thermal Controlled Modules. The later technology lent itself to air cooling.
I want to say the buzzwords were BIPOLAR and CMOS. BIPOLAR was very fast and very small, but very, very expensive. CMOS was much slower, but vastly cheaper to include being air cooled. CMOS eventually caught up with and surpassed BIPOLAR. Of course, my brain bone has aged and may be totally out there. :-) -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Martin Packer Sent: Tuesday, February 16, 2010 2:14 PM To: [email protected] Subject: Re: What was old is new again (water chilled) Perhaps someone could summarise cogently what was wrong with water cooling the first time around (which, yes, I was there to witness). :-) I surmise it wasn't the water cooling so much as the space and the energy consumption that caused it to be necessary. Martin Packer, Mainframe Performance Consultant, Software Group Worldwide Banking Center of Excellence, IBM +44-7802-245-584 email: [email protected] Twitter / Facebook IDs: MartinPacker IBM Mainframe Discussion List <[email protected]> wrote on 16/02/2010 19:23:08: NOTICE: This electronic mail message and any files transmitted with it are intended exclusively for the individual or entity to which it is addressed. The message, together with any attachment, may contain confidential and/or privileged information. Any unauthorized review, use, printing, saving, copying, disclosure or distribution is strictly prohibited. If you have received this message in error, please immediately advise the sender by reply email and delete all copies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
