EEVblog #1341 - AMAZING $250,000 IBM Processor Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: October 05, 2020, 11:07:22 pm
content: Teardown of a $250,000 1991 vintage IBM 9121 TCM Processor module from a System/390 ES9000 Enterprise Server mainframe computer,.Amazing state of the art 63 layer ceramic hybrid module construction with 2772 pins!And Dave demonstrates an amazing BGA desoldering technique that can only be done on these ceramic hybrid PCB's.TCM PDF:https://eevblog.com/files/ibm-system390-air-cooled-alumina-thermal-conduction-module.pdf

author: DrG
author_rank: Super Contributor
timestamp: October 06, 2020, 12:05:24 am
content: Bizarre and fascinating.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 06, 2020, 01:04:25 am
content: Awesome! Love this kind of stuff.

author: schmitt trigger
author_rank: Super Contributor
timestamp: October 06, 2020, 02:06:06 am
content: This is back when IBM was light years ahead of everyone else.

author: Tom45
author_rank: Frequent Contributor
timestamp: October 06, 2020, 03:07:46 am
content: Apparently there are 4 capacitors per package? If so, why 4 connections per capacitor?

author: Bud
author_rank: Super Contributor
timestamp: October 06, 2020, 03:24:11 am
content: More mainframe processor modules porn here:https://www.eevblog.com/forum/vintage-computing/ibm-mainframe-and-server-cpus/

author: daqq
author_rank: Super Contributor
timestamp: October 06, 2020, 05:56:27 am
content: Dave, thanks for the teardown, delightful to watch, although there were a few painful moments, wrecking a museum grade piece like that - ouch.Quote from: Tom45 on October 06, 2020, 03:07:46 amSpecial package that minimises inductance. See:http://www.avxcorp.com/docs/techinfo/DecouplingLowInductance/flipchip.pdf

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 06, 2020, 08:09:42 am
content: Small correction to this amazing video:@24:30The paper you inserted says the solder alloy is 97Pb/3Sn which is Lead / Tin, not Tin/Copper as you stated.This also fits better with the softness of the solder.

author: aqarwaen
author_rank: Regular Contributor
timestamp: October 06, 2020, 09:03:16 pm
content: i wonder if theys ibm computer systems where this cpus where used,also supported that giant hdd what dave teardown in one of his videos?

author: nctnico
author_rank: Super Contributor
timestamp: October 06, 2020, 09:37:18 pm
content: Quote from: Doctorandus_P on October 06, 2020, 08:09:42 amDon't think so. I strongly doubt that that alloy has such a low melting point that is is basically liquid at room temperature. It has to be something else.

author: Little Brutus
author_rank: Unknown
timestamp: October 06, 2020, 11:42:46 pm
content: I worked on one of these from ~94 to 99. Machine ended up being sold for scrap. A 2 frame 9121 (model 732 I *think*)I got a souvenir, a couple of the heat sinks from that machine.They are about 5 KG each and look like aluminum.

author: Little Brutus
author_rank: Unknown
timestamp: October 07, 2020, 12:19:55 am
content: Looks like 97Pb/3Sn has a 315C melting point according to US Patent 7838954"The use of such high-melting alloys forchips provides a hierarchy in soldering temperatures so thatthe 97Pb-3Sn solders (melting temperature 315° C.) on theside of the chip do not melt and the under bump metallurgy isnot consumed during the next level ?ip chip assembly usingloW melting solders such as eutectic 37Pb-63Sn solders Witha melting temperature of 183° C."

author: jgruszynski
author_rank: Newbie
timestamp: October 07, 2020, 11:45:31 pm
content: Cool.I have been to the factory that made these in the late 1980s. It was manufactured at a site that no longer exists: IBM Manassas Virginia.I was working for the US Air Force Space Division doing military space electronics and they were one of our major vendors. I visited IBM frequently at multiple sites.So IBM's big challenge was mastering was getting the ceramic shrinkage exactly characterized - the ceramic is a "multi-level" ceramic that has multi-level interconnects just like an IC's metallization except it's all laid down as multiple wet ceramic clays with metal layered and then fired. The magic is still achieving the exact dimensions despite shrinkage during firing. No one really has duplicated the capability until the last 10 years with stuff like Amkor and TSMC are doing with chiplets.We were interested in the density, weight and reliability for space applications. It was high density with high performance with low total weight compared to PCBs and other alternatives.

author: jgruszynski
author_rank: Newbie
timestamp: October 07, 2020, 11:52:24 pm
content: Yes the die are "flip-chips" and simply pressed by the heat sinks and springs holding them in.The interconnects in inside the ceramic substrate. The die are NOT all the same. Some may be memory/cache, some processors, some glue logic.Brings back memories!

author: Bud
author_rank: Super Contributor
timestamp: October 08, 2020, 12:00:53 am
content: Quote from: jgruszynski on October 07, 2020, 11:45:31 pmWow, interesting!

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 08, 2020, 03:05:28 am
content: Why is the CPU assembly so complex for what appears to be a modest number of MIPS even back then? Are the instructions far more complex than x86 instructions or is it more about memory and I/O bandwidth?

author: VK3DRB
author_rank: Super Contributor
timestamp: October 10, 2020, 11:35:06 am
content: There was some other technology IBM produced that was fascinating. The 028 and 129 card punches had a thing in them called a code plate and an elephants trunk for printing characters. The code plate had a large array of tiny square protrusions, where with a certain x and y displacement, and then displacing in the z direction would hit specific protrusions on the elephant's trunk to print a character (5 x 7 dot matrix). I never worked out how these code plates were made. The lynx belt printer was also one of their achievements.Another fascinating device were the early Winchester hard disks. One I worked on could be as big as 5.1MB in the System/32, but it took two men to lift it. They cost today's equivalent of about $200,000. Let's not forget the 5225 "washing machine" printer. Very high speed dot matrix printer, that had 8 heads firing off at once, with massive transistors driving high current to the wires. Ceramic substrates were common on all this equipment. You will find them on any aluminium covered IBM chip - just peel the cover off and a jelly covered the chips (not an oil).There were a lot of innovations IBM had that were not used elsewhere, possibly due to patents. I was fortunate to have worked these and a lot more in my first job at IBM.By the way, the first TCM's around 1980 were about $25K, so in today's money, about $250K. And that was the IBM INTERNAL price as I recall. You would not want to have had one replaced and not be covered by maintenance contract.

author: EEVblog
author_rank: Unknown
timestamp: October 10, 2020, 11:49:09 am
content: Quote from: VK3DRB on October 10, 2020, 11:35:06 amI found an article from the early 90's about IBM hiking the prices on these modules. The exact one in this video was $225,000refurbished.

author: EEVblog
author_rank: Unknown
timestamp: October 10, 2020, 11:51:29 am
content: Quote from: Doctorandus_P on October 06, 2020, 08:09:42 amYes, I confused this with standard 97/3 lead free solder.

author: amyk
author_rank: Super Contributor
timestamp: October 12, 2020, 06:37:03 am
content: Any datasheet, or schematic available for this...?

author: cclark001
author_rank: Newbie
timestamp: October 15, 2020, 07:46:56 am
content: I worked at IBM rival Amdahl for awhile. One reason for "lower than you would expect" MIPS was resiliency.Not to get into the weeds of logic design too much, but unexpected settings of the state machines in the CPU were monitored and if one was encountered, the CPU would pause and probe the logic levels of surrounding state machines and then decide what was wrong and overwrite a correct values over the miscreant. The CPU would resume as if nothing had happened. There was a time limit of how much incoming data could be buffered without overflowing. A modem would report the hit back to the home office.New designs or misbehaving CPUs could have hundreds of these soft errors an hour and it would just keep chugging along with uptimes sometimes into the hundreds of days. No outages allowed for big iron customers and the customers would pay crazy prices - as seen in the price of this IBM module, wow.

author: Twoflower
author_rank: Frequent Contributor
timestamp: October 16, 2020, 02:40:17 pm
content: Nice teardown. But did the IBM guys actually had to bodge wire that monster?That could probably the reason why not all places are populated. Some places are not working correctly.