Xref: utzoo comp.sys.hp:1030 comp.arch:6124 Path: utzoo!utgpu!attcan!uunet!mcvax!enea!kth!draken!bmc1!kuling!irf From: irf@kuling.UUCP (Bo Thide) Newsgroups: comp.sys.hp,comp.arch Subject: Sun f77 -fswitch overhead. Comparison with HP9000/350. Message-ID: <754@kuling.UUCP> Date: 21 Aug 88 17:28:08 GMT Distribution: comp.sys.hp Organization: DoCS, Uppsala University, Sweden Lines: 92 >From sun-spots Vol 6: Issue 172: >>From: Jim Barby>Subject: Re: Revenge of the 68881 >Reference: v6n152 >In v6152 Dave Bernholdt was surprised about the high overhead -fswitch >has. I did some bench marking a few weeks back and sent off a request to I ran the ratfor program on my HP9000/350 (where -fswitch is +bfpa) which has the same hardware as the Sun3/260. As is clear from the results below, the HP +bfpa also has a high overhead. But I was surprised to see how much faster code the HP f77 produces -- almost twice as fast as Sun's! Note that I am not using the new, faster (and cheaper, sic) HP FPA. (I did'n run the test without the write statement since currently HP f77 only has an assembly code optimizer.) Comments? -Bo >>> Bo Thide', Swedish Institute of Space Physics, S-755 91 Uppsala, Sweden <<< >>> Phone: (+46) 18-403000. Telex: 76036 (IRFUPP S). Fax: (+46) 18-403100 <<< >>> INTERNET: bt@irfu.uu.se UUCP: ...enea!kuling!irfu!bt <<< ==== The posted ratfor program (I changed 0 to 6 in write statemnt - BT) ==== define N 10000000 double precision data(2), add, sub, mul, div integer i data(2) = 1 do i=2,N { data(1) = data(2) data(2) = i add = data(2) + data(1) sub = data(2) - data(1) mul = data(2) * data(1) div = data(2) / data(1) } write(6,*) add, sub, mul, div stop end ------------------------------------------------------------------------ ========hardware configuration========================================= node name short name equipment ---------------+---------------+------------------------------ watvlach vlach older 3/50 with new MC68881 vlsisun1 sun1 older 3/160 with old MC68881 vlsisun2 sun2 3/160 with new MC68881 and FPA vlsisun3 sun3 3/260 with MC68881 node name short name equipment ---------------+---------------+--------------------------------- heating.irfu hp350 HP9000/350 with 68881 and old FPA ========test results with and without -O compile flag================== cpu cpu times in minutes without using -O name -fsoft -f68881 -ffpa -fswitch -------+-------+-------+-------+-------- vlach 56.0 14.0 ---- 20.1 sun1 52.6 10.1 ---- 20.8 sun2 52.8 12.2 5.1 10.2 sun3 29.4 10.3 ---- 13.5 name +M (68881) +ffpa +bfpa -------+-------+-------+-------+-------- hp350 15:28 9:23 3:57 5:25 cpu cpu times in minutes using -O name -fsoft -f68881 -ffpa -fswitch -------+-------+-------+-------+-------- vlach 56.7 14.2 ---- 21.3 sun1 53.3 15.4 ---- 22.3 sun2 53.4 12.5 2.0 10.8 sun3 29.8 10.4 ---- 14.0 name +M (68881) +ffpa +bfpa -------+-------+-------+-------+-------- hp350 15:30 4:39 1:44 4:30 -- >>> Bo Thide', Swedish Institute of Space Physics, S-755 90 Uppsala, Sweden <<< Phone (+46) 18-300020. Telex: 76036 (IRFUPP S). UUCP: ..enea!kuling!irfu!bt