[net.arch] dhrystones on the IBM RT PC

eriks@yetti.UUCP (Eriks Rugelis) (01/30/86)

we received a brand new IBM RT PC on a one week demo from IBM;  i thought
i'd run a quick series of simple benchmarks for rough speed comparisons

the machine is an IBM RT PC running the Interactive Systems port plus
modifications of
AT&T System V.1 that IBM has named AIX (Advanced Interactive eXecutive)

the machine is configured with:
	2 MB and the floating point accelerator board on the system bus
	a PC/AT co-processor board with its own 1/2 MB memory on the PC bus
	various other peripherals (asynch. terminal mux, disk controller..etc
	   on the PC bus)
	a 70 MB hard disk and an IBM 1.2 MB floppy drive

i believe that this is known as a Model 20 in the RT PC series (maybe a Model
25, i don't have my RT PC glossies handy)

i ran a copy of the dhrystone benchmark, put together by Rick Richarson, and
labeled as Version C/1 dated 12/01/84

as AIX booted it reported its version as 'B47 release 1 version 0'  (for all
i know this might just as well be referring to the version of the Virtual
Resource Manager... i don't know... does ANYONE?)

at 50K iterations
the no-register benchmark clocked in at 1736 dhrystones/second
the register benchmark produced 1879 dhrystones/second

at 500K iterations the register benchmark produced 1883 dhrystones/second

compiling with the fcc command that allows use of the floating point accelerator
did not yield any different numbers

i also compiled and ran David Hinnants C language port of the single
precision whetstone benchmark

using the admittedly crude technique of using a time command to gather
numbers, 1 million iterations took about 5 seconds or less to complete
the whetstone benchmark was run with the floating point board enabled

observations and comments:
IBM claims that the RT PC is a '2 MIPS' machine... the dhrystones seem to
bring to the fore the contrast between CISC and RISC mips...   a VAX 780
clocks around 1500 dhrystones and a 785 clocks around 2100...  
i have heard these to be described as about 1 and 1.5 mips machines respectively

IBM claims about 200K single whetstones/second...  my gross measurements appear
to bear this out

trademarks:
this article is full of references to trademarks owned by several corporate
entities;  the reader is hereby advised not to take these tm's in vain

more comments:
the RT that i used today spent the previous night in a truck in -12C weather...
it was delivered in the morning and allowed warm-up through-out the day before
being turned on....   if this example is any indication, these machines seem
to stand up well to freeze-drying

a flame:
AIX continues the IBM tradition of:
	distributing UNIX like systems       BUT,
	not associating the name UNIX with said systems    AND,
- - ->  not including machine-readable documentation with the distribution
	of the operating system; not even committing to EVER providing
	machine readable documentation of ANY sort

i like on-line manuals;  i bet you do too;  if you have any contact with IBM,
tell them..  then tell them again
-- 
          Voice: Eriks Rugelis
        Ma Bell: 416/665-8585 x6308
         USENET: {allegra|decvax|ihnp4}!utzoo!yetti!eriks
NETNORTH/BITNET: eriks@yuorion
          QUOTE: Of all the things I've lost, I miss my mind the most

mcgrath@uicsrd.CSRD.UIUC.EDU (02/03/86)

>/* Written 11:52 pm  Jan 29, 1986 by eriks@yetti.UUCP in uicsrd:net.arch */
>/* ---------- "dhrystones on the IBM RT PC" ---------- */
>we received a brand new IBM RT PC on a one week demo from IBM;  i thought
>i'd run a quick series of simple benchmarks for rough speed comparisons
> ....
>compiling with the fcc command that allows use of the floating point accelerator
>did not yield any different numbers

We also saw a demo.  The IBM rep "didn't want to talk about floating point"
with the implication that it didn't really exist yet.  Who knows?

	R. E. McGrath
	mcgrath%uicsrd@uiuc.arpa
	uiucdcsa!uicsrd!mcgrath

rentsch@unc.UUCP (Tim Rentsch) (02/07/86)

I just read an IBM product announcement for the RT PC.  The bottom
line on floating point:

	200,000 whetstones

(compared to 750,000 on a vax780, or 1,150,000 for 780 with FPA).

well, it's a benchmark.

# "i can't resist adding the following -- just this once, i promise"
#
#   self standardDisclaimer.
#   self signature.
#
# "take that, you C fanatics"

stubbs@ncr-sd.UUCP (Jan Stubbs) (02/08/86)

In article <1000008@uicsrd> mcgrath@uicsrd.CSRD.UIUC.EDU writes:
>
>We also saw a demo.  The IBM rep "didn't want to talk about floating point"
>with the implication that it didn't really exist yet.  Who knows?
>
I saw the IBM/RT at uniforum. A friendly person who claimed to head up
the chip development team at Austin, Texas said the following:

The floating point chip is a National Semiconductor NS32????. The ROMP is 
not an 801 (which was a discrete system) but used some similar concepts.
It has a 23Mhz clock but uses four clocks per cycle which gives it a
170NS cycle time. 80 out of 120 instructions execute in 1 cycle, but the
average cycles per instruction was >3. Load and store take 5 cycles each.
There is no cache. There is a 16 word instruction buffer. The MMU was
added late in the design (presumably to run UNIX??). There are 16 General
purpose registers.

The operating system emulates DOS commands, so I believe that copy a b
does the same as cp a b if you are in DOS mode. Only one person
can use the 80286 at a time. The 80286 is an option. Xenix was also
shown in the booth along with some applications such as accounting
and engineering stuff.

I also saw a 12 cpu Encore Multimax running a similated load with 128
processes. While this was running I logged on and ran a 'C' compile, which
completed in a very reasonable time considering the load.


Jan Stubbs    ....sdcsvax!ncr-sd!stubbs
NCR Corp.
San Diego