RS6000 sizing for fast printers
ITEM: RTA000151512
Q:
Topic thread:
Printer Systems (PRINT - NA/ATS)
PSF/AIX
PRINT XPSF6000
I have looked through QAR entries on sizing and reviewed the publication
"PSF/6000 Performance Information" and cannot find anything that seems
to address this particular requirement. I would assume that the
environment would be PSF Direct and so the processing load on the
RS/6000 would be quite light (since no conversion is necessary) and
so I would look to a medium machine (250?). If they decide not to use
PSF Direct then I would expect the spooling requirement to dictate that
more than one RS/6000 be used. Unfortunately I cannot find any figures
to justify this belief. Can you please either confirm/deny my
assumptions or direct me to some useful publication?
------------------------------------------------------------------------
Question:
Abstract: RISC/6000 SIZING TO DRIVE 9 LARGE AFP PRINTERS
A customer is running a print shop with the following machines:
2 x 3825
2 x 3827
3900-001
3900-PQE
3900-0W1
4000-ID1/2
2 x 4245
6262
All the machines are now channel attached to an MVS host system.
We want to propose a remote RISC/6000 based solution and the questions
are:
1 which is a possible Risc machine able to drive 9 laser printers in an
AFP environment? Monthly print volumes are: 1.6 Miopages A4,
5 MioPages 8,5". Page complexity range from simple line print job to
medium OGL AFP prints.
2. Is it possible to connect 6400 ASCII printers to risc driving them by
the remote MVS host using JES 328x to convert the spool from host to
RISC environment?
3. Do we need DB2/6000 (as we need DB2/2 in a PSF/2 environment) to
manage all the AFP resources (overlays, images etc.)
------------------------------------------------------------------------
A:
I'm assuming your question is for PSF/AIX rather than InfoPrint Manager
for AIX (since it was the PSF/AIX queue to which it was assigned) though
neither the text nor the abstract stated that explicitly.
In order to do a sizing, additional information is required, even for a
PSF Direct environment. There is a PSF Direct Performance Guide (albeit
somewhat dated) that's available as part of the PSF6PERF PACKAGE on the
PENNCONF disk. I strongly recommend that you REQUEST this file and
review it. If you're unable to obtain it, please reopen this item. The
document reviews the behavior of a number of different sample jobs from
the AFP Catalog of Performance Pages, so you can see some of the effects
of varying job complexity. (But that's just a small piece of the puzzle
as you'll see below.)
Let me say first neither PSF/AIX nor InfoPrint Manager, nor even native
AIX will support the 4245s or a non-Axx 6262. Since your abstract
mentions a sizing to drive 9 AFP printers (the 3825s, 3827s, 3900s, and
InfoPrint 4000) I'm not sure if this will be an issue for you or not,
but I wanted to call it to your attention in the event that you were
expecting to drive the 4245s or a non-ASCII 6262 from the RS/6000.
What model are you referring to when you say 3900-PQE? I know what
PQE is, but don't know specifically which model 3900 you are referring
to and how many impressions/minute.
R1) You will not be able to drive all these AFP printers (2 3825s, 2
3827s, 1 3900-001, 1 3900-PQE (?), 1 3900-0W1, and 1 InfoPrint 4000
duplex ID1/ID2) from a single RS/6000.
The first mitigating factor is that at least five of these systems must
be channel-attached (2 3835s, 2 3827s, 1 3900-001, perhaps the 3900-PQE
depending on what it really is).
- Each channel-attached printer must be attached to its own separate
S/370 Channel Emulator/A adapter (f/c 2759 on RS/6000s); you cannot
daisy-chain multiple printers off a single adapter under PSF/AIX or
InfoPrint Manager, though you can with PSF/2.
- You cannot put any more than four S/370 Channel Emulator/A adapters
in a single RS/6000, and I don't know of anyone doing as many as
four in actual practice˘ At some point, you will exceed the
capacity of the microchannel bus that servers those adapter slots.
- The S/370 Channel Emulator/A is a microchannel device only;
therefore, you will require at least two microchannel RS/6000s.
- If the RS/6000s have more than one microchannel bus (like the 595),
the S/370 Channel Emulator/A adapters are only supported by PSF/AIX
or InfoPrint Manager when the adapters are installed in the slots in
bus0.
The second factor is the sheer number of pages you're asking PSF Direct
to handle, even though it largely just passes the data through. For a
realistic sizing for this configuration, additional information will be
required.
- For example, you state that page complexity will range from simple
line data to medium OGL AFP print. How many bytes per page? Is
there any image data, and if so, how much?
- Are any of the printers printing multiple-up or n-up?
- What is the total number of impressions/minute you require PSF
Direct to process simultaneously? Since you already know that
more than one RS/6000 will be required to support this number of
printers, it would be very helpful if you can try to balance the
number of IPM across the multiple RS/6000s. Or if you can specify
the number of impressions per minutes for each of the nine printers,
we can try to assist. I can't do it without additional input from
you as to if any of the printers will be printing n-up, etc.
- What is the complete network configuration between the Host and the
RS/6000 (including any communications controllers or routers)?
Is there sufficient bandwidth between the host and the RS/6000 to
support the data rate that will be required to drive the printers
at rated speed? Keep in mind that printing in this environment will
only be as fast as the slowest bottleneck in the overall
configuration. As stated in the "Performance of PSF Direct on PSF/2
and PSF/6000" (the document I referred to earlier):
"Printing performance with PSF Direct is affected by the printer
data stream and the characteristics of the jobs being printed, as
well as these five elements of the configuration:
1. Limitations of the Host system: If the host has an inadequate
configuration (processor power, memory, DASD) for its workload
(including the PSF work), the rate of delivering data to the
printer through PSF Direct may be too slow to maintain
maximum throughput. Throughput can also be reduced if
priorities don't allow the Host PSF to work fast enough.
2. Limitations of the attachment between the Host and PSF Direct:
The Host channel, the LAN Gateway Controller, any intervening
LANs and communications links, and the LAN on which PSF Direct
resides must be able to supply the data rate required by the
printer's maximum rate for the job.
3. The power of the hardware platform on which PSF Direct is
running: The data rate to the printer may be reduced if the
PS/2 or RISC System/6000 processor isn't powerful enough.
More processor power will be needed when printing to non-IPDS
printers, because additional data stream conversion is
necessary.
4. Limitations of the attachment between PSF Direct and the
printer: Some printer attachments may reduce printing
throughput. For example, the parallel port of a PS/2 will
probably limit the performance of most applications.
5. The performance of a printer, given the job's characteristics:
Some jobs may be so complex that a particular printer can't
print them at rated speed regardless of the other performance
elements.
"Overall printing throughput will be determined by the slowest of
these five elements."
R2) You cannot use JES/328X to send data from an MVS system to an
ASCII 6400 driven by the RS/6000. If you want to send data from MVS to
a 6400, you have several options:
- With PSF/AIX or InfoPrint Manager, you can use PSF Direct from
host PSFs to an IPDS 64xx, supported to the extent that the host
PSF would support that IPDS 64xx.
- With InfoPrint Manager (not PSF/AIX), you can spool print jobs to
an IPDS 64xx. These jobs could be submitted from LAN clients or
through LPD from different platforms or through MVS Download, to
name a few. There is a libraried WWQ&A item that has much more
detail on this configuration. If you are unable to find the item
by searching on InfoPrint and 6400, please reopen so I can provide
the item number.
- You can submit host line data jobs (EBCDIC) to an ASCII 64xx or
other ASCII printers driven by AIX a number of ways.
- TCP/IP:
- IP Printway (perhaps with Netspool)
- MVS TCP/IP's LPR
- MVS TCP/IP's Network Print Facility (superseded by Printway)
- SNA:
- IBM 3270 Host Connection Program (HCON)
There are OEM products that would also enable you to send output from
MVS to an ASCII 64xx, but the above list includes the IBM options.
R3) DB2 for AIX has never been a requirement for PSF/AIX, either for
LAN print submission or for PSF Direct; this should be apparent from the
PSF/AIX salesmanual entry and the announcement letters.
Keep in mind that PSF Direct does not utilize resources stored
at the RS/6000; rather it passes those resources down in the IPDS sent
from the host PSF to the AFP printer through the PSF Direct Host
Receiver code (part of PSF/AIX or InfoPrint Manager on the RS/6000).
Also be aware that neither PSF/AIX nor InfoPrint Manager offer a true
equivalent to PSF/2's DPF.
If you provide the additional information I requested, then we'll do our
best to assist. The more information you can provide, the better our
estimate will be.
S e a r c h - k e y w o r d s:
psf/6000 psf/aix psf aix infoprint pod sizing performance bandwidth
direct 6400 64xx jes/328x ascii ebcdic dpf psf/2 db/2 4245
WWQA: ITEM: RTA000151512 ITEM: RTA000151512
Dated: 08/1998 Category: XPSF6000
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