Solution* for Chapter X Exarclsm
1.49 Possible solutions:
Ethernet, IEEE 802.3, twisted pair cable, 10/100 Mbit
Wireless Ethernet, IEEE 802.1 lb, no medium, 11 Mbit
Dialup, phone lines, 56 Kbps
ADSL, phone lines, 1.5 Mbps
Cable modem, cable, 2 Mbps
1.50
a. Propagation delay = mis sec
Transmission time = LIR sec
End-to-end delay =m/s+L/R
b. End-to-end delay =mls+ LJR+t
c. End-to-end delay = mis + 2I/R + f/2
1.51 Cost per die = Cost per wafer/(Dies per wafer x Yield) = 6000/( 1500 x 50%)
= 8
Cost per chip = (Cost per die + Cost_packaging + Cost_testing)/Test yield =
(8 + 10)/90% = 20
Price = Cost per chip x (1 + 40%) - 28
If we need to sell n chips, then 500,000 + 20« = 28», n = 62,500.
1.52 CISCtime = Px8r=8Prns
RISC time = 2Px 2T= 4 PTns
RISC time = CISC time/2, so the RISC architecture has better performance.
1.53 Using a Hub:
Bandwidth that the other four computers consume = 2 Mbps x 4 = 8 Mbps
Bandwidth left for you = 10 - 8 = 2 Mbps
Time needed = (10 MB x 8 bits/byte) / 2 Mbps = 40 seconds
Using a Switch:
Bandwidth that the other four computers consume = 2 Mbps x 4 = 8 Mbps
Bandwidth left for you = 10 Mbps. The communication between the other
computers will not disturb you!
Time needed = (10 MB x 8 bits/byte)/10 Mbps = 8 seconds
评论6