[email protected] (Jim Mulder) writes:
> it might be faster to read it from the DB2 data set, because DB2
> (via Media Manager) uses zHPF, but z/OS has not been enhanced to 
> use zHPF for page data sets. 

in 1980, I got con'ed into doing channel-extender for STL that was
moving 300 people from the IMS group to offsite bldg. with service back
to STL datacenter. It had channel emulator box at the offsite bldg with
local channel attached 3270 controllers at the offsite bldg. there was
full-duplex streaming protocol with the offsite channel emulator with
channel programs downloaded ... significantly mitigated the latency of
the heavy duty half-duplex channel protocol chatter.
http://www.garlic.com/~lynn/submisc.html#channel.extendeer

The vendor tries to get IBM to release my support ... but there was
group in POK that was playing with some serial stuff that blocked it
because they were afraid that it would make it more difficult to get
their stuff released.

In 1988, I'm asked to help LLNL get some stuff they are playing with
standardized ... which quickly becomes fibre channel standard ...  it
includes full-duplex streaming (initially 1gbit/sec in both directions)
and downloading i/o programs (countermeasure to protocol chatter
latency).

In 1990, the POK serial stuff is finally released as ESCON, when it is
already obsolete.

Later some POK people become involved in fibre channel standard and
define a heavy weight, high latency protocol chatter protocol that
significantly cuts native throughput that is eventually released
as FICON
http://www.garlic.com/~lynn/submisc.html#ficon

Most recent published "peak I/O" benchmark I've seen is for z196 that
got 2M IOPS with 104 FICON (running over 104 fibre channel standard).
About same time there was a fibre channel standard announced for e5-2600
blade that claims over million IOPS (for single FCS, two would have
higher native throughput than 104 FICON).

zHPF w/TCW describes something a little like what I originally did back
in 1980 ... but says it only provides 30% improvmeent over standard
FICON (possibly only 70 FICON to get 2M IOPS, compared to only two fiber
channel getting over native 2M IOPS).

This recent post about 1987 (IBM) disk "wide-head" proposal capable of
something like 48-67mbytes/sec transfer ... by 1990, FCS would have
over 100mbyte/sec (1gibt/sec) full-duplex. At the time standard IBM had
3mbyte/sec channel moving to 4.5mbyte/sec ... and ESCON in 1990 would
only be be 17mbytes/sec ... so as an IBM product, "wide-head" wasn't
feasible.
http://www.garlic.com/~lynn/2017d.html#54 GREAT presentation on the history of 
the mainframe
http://www.garlic.com/~lynn/2017d.html#60 Optimizing the Hard Disk Directly

recent paging subsystem posts here
http://www.garlic.com/~lynn/2017d.html#58 Paging subsystems in the era of 
bigass memory
http://www.garlic.com/~lynn/2017d.html#61 Paging subsystems in the era of 
bigass memory
http://www.garlic.com/~lynn/2017d.html#63 Paging subsystems in the era of 
bigass memory
http://www.garlic.com/~lynn/2017d.html#65 Paging subsystems in the era of 
bigass memory
http://www.garlic.com/~lynn/2017d.html#66 Paging subsystems in the era of 
bigass memory

-- 
virtualization experience starting Jan1968, online at home since Mar1970

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