On Jun 19, 2010, at 10:08 AM, Dan wrote:
WRT the cooling... I always found it interesting that companies like Amdahl had air-cooled mainframes that were faster than IBM's twitchy chilled water systems. That mess was all about power and heat sink patents and licensing, and the bad blood between the two companies...
Amdahl had a patented cooling method (convection "heat pipes", one per chip, and push-pull forced-air cooling of each column of MCCs) invented by none other than Dr Gene, himself, as he had a PhD in physics. Of course, Dr Gene was the primary architect of the System/360.
Until IBM got serious about being competitive, Amdahl was usually about 2.4-2.7 times as fast as the related IBM product, whether that product was a mainframe (3168/470V6, for example) or a communications controller (3705/4705, for example).
Amdahl made at least three generations of S/370-type mainframes which were all air-cooled, then we had to convert to water-cooling on account of the heat load per chip. In that model, we used the same cooling plate design as IBM would later use in its 3090 series.
Amdahl and IBM cross-licensed many patents, particularly those regarding fast multipliers and prediction of condition codes. Also prediction of parity and ECC.
IBM did not achieve the same basic feature (air-cooling) until their Generation 1 (AKA, G1) CMOS machines of almost two decades later. IBM is now at G7, or something like that, and Amdahl is out of business (liquidated), thanks to the incredibly bad decision-making of majority owner Fujitsu LTD.
Peter ... proud to have been an Amdahl employ for two decades. -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
