badri@ur-valhalla.UUCP.UUCP (02/05/87)
I simulated a 7 inverter CMOS ring oscillator on spice 2 and spice 3 on several machines running unix BSD4.2 (or derivatives) to compare results. I got some rather interesting statistics, which, I thought might interest other users. I am posting the statistics as well as the spice deck that I ran. No conclusions drawn; I tried as far as possible to run the jobs on lightly loaded machines. All times are from /bin/time. Badri Lokanathan -- spice deck cring.in run on spice 3a7: MACHINE HARDWARE SPECS. REAL USER SYS ------- --------------- ---- ---- --- Pyramid 90x 8M core, no f.p.a. 273.3 244.1 3.6 Sun 3/280 8M core, 68881 acc. 258.1 252.9 2.3 VAX 11/750 4M core, f.p.a. 527.5 158.5 7.7 VAX 11/750 2M core, f.p.a. 451.0 414.7 8.3 VAX 11/750 2M core, no f.p.a. 494.8 432.0 11.8 ------------------------------------------------------------------- spice deck cring.in run on spice 2g6: MACHINE HARDWARE SPECS. REAL USER SYS ------- --------------- ---- ---- --- Pyramid 90x 8M core, no f.p.a. 374.7 326.7 7.2 Sun 3/280 8M core, 68881 acc. 304.2 294.9 1.7 VAX 11/750 4M core, f.p.a. 732.5 241.6 15.4 VAX 11/750 2M core, f.p.a. 662.0 560.1 17.2 VAX 11/750 2M core, no f.p.a. 722.6 592.7 24.0 ------------------------------------------------------------------- spice deck cring.in: * CMOS Ring oscillator (7 inverters) * * Transistors : mq1n 2 1 0 0 CMOSN l=3u w=4.5u mq1p 2 1 100 100 CMOSP l=3u w=4.5u mq2n 3 2 0 0 CMOSN l=3u w=4.5u mq2p 3 2 100 100 CMOSP l=3u w=4.5u mq3n 4 3 0 0 CMOSN l=3u w=4.5u mq3p 4 3 100 100 CMOSP l=3u w=4.5u mq4n 5 4 0 0 CMOSN l=3u w=4.5u mq4p 5 4 100 100 CMOSP l=3u w=4.5u mq5n 6 5 0 0 CMOSN l=3u w=4.5u mq5p 6 5 100 100 CMOSP l=3u w=4.5u mq6n 7 6 0 0 CMOSN l=3u w=4.5u mq6p 7 6 100 100 CMOSP l=3u w=4.5u mq7n 1 7 0 0 CMOSN l=3u w=4.5u mq7p 1 7 100 100 CMOSP l=3u w=4.5u * * Voltage cards : vdd 100 0 dc 5V * * Analysis cards : .tran 100ps 20ns .plot tran v(1) v(7) .ic v(1)=0 v(3)=0 v(5)=0 v(7)=0 * * Model cards : .MODEL CMOSN NMOS (VTO=0.83 KP=33U GAMMA=1.36 PHI=0.6 + LAMBDA=0.016 PB=0.8 JS=10N LD=0.28U TOX=50N NSUB=1E16 + UO=200 UEXP=0.1 UCRIT=4E4 VMAX=100K XJ=0.4U + DELTA=1.24 NFS=0 NEFF=2 NSS=0 TPG=1.0 RSH=25 + CGSO=0.5N CGDO=0.5N CJ=0.32M MJ=0.5 CJSW=0.9N MJSW=0.33 + CGBO=0 FC=0.5 LEVEL=2) .MODEL CMOSP PMOS (VTO=-0.89 KP=15U GAMMA=0.88 PHI=0.6 + LAMBDA=0.047 PB=0.8 JS=10N LD=0.28U TOX=50N NSUB=1.12E14 + UO=100 UEXP=0.1 UCRIT=20E4 VMAX=100K XJ=0.4U + DELTA=1.94 NFS=0 NEFF=2 NSS=0 TPG=-1.0 RSH=95 + CGSO=0.4N CGDO=0.4N CJ=0.2M MJ=0.5 CJSW=0.45N MJSW=0.33 + CGBO=0 FC=0.5 LEVEL=2) .end