The computer bus transfer rate
Bus data transmission rate = clock frequency (Mhz) / number of clock cycles of the bus comprises a number * (b) of each byte is transmitted in each bus cycle
The computer system speed
The number of instructions per second = clock frequency / number of clock cycles comprising each bus / instruction bus cycle number average occupancy
average bus cycles = sum of all instructions categories (average number of bus cycles frequency of use)
number of bus cycles included in the control program = (number of instructions the number of bus cycles / instruction)
the number of instructions = number of instructions using the frequency / total instruction use frequency
number of bus cycles per second = frequency / clock cycle
FSB = FSB frequency bandwidth of FSB bit width / 8
Reservoir
Memory bandwidth: the number of bits per second to access the unit ns = 10-9 s
memory bandwidth = 1 sec / cycle memory (ns) the number of bytes per cycle accessible
(Random Access) transmission rate = 1 / memory cycle
(non- random access) to read and write N-bit time required for the average access time = average + N bits / data transfer rate of
the memory chip number: (W is / W) (B / B) W is, B represents the number of words to be composed of a memory and bits;
W, B represents the number of words and bits memory chips
memory address code = (second address - the first address) +1
{Example: [(CFFFFH-90000H) +1 ] / [(16K * 1024) * 8bit ]}
memory bits: (number of bytes or words to be addressed) Iog2
Network traffic
a: the length of the frame count
A may be a propagation delay / time send a
data rate of a line length / propagation velocity / frame length of
the data rate of the propagation delay / frame length
λ protocols such as the maximum link utilization stop E = 1 / (2a + 1 )
W: window size
[lambda] sliding window protocol E = W is / (. 2A +. 1)
P: frame error probability
[lambda] wait ARQ protocol E = (. 1-P) / (. 2A +. 1)
[lambda] Selective Repeat ARQ protocol
if W> 2a +1 for E = 1-P
if W <= 2a + 1 = W is the E (. 1-P) / (. 1 +. 2A)
[lambda] Back N ARQ protocol frame
if W> 2a + 1 is E = (1-P) / (1-P + NP)
if W <= 2a + 1 then the E = W (1-P) / (2a + 1) (1-P + NP)
IP addresses
Network number assigned network number bits = 2 ^
maximum number of hosts in the network host number = 2 ^ -2 digits Example: Host No. 10 ^ 10 -2 = 2 = 1022
the IP network number and a subnet number of bits taken mask
Example: IP: 176.68.160.12 network median: 22
subnet: IP-> binary -> network whole number 1, the host 0-> subnet
before 22 1, after the 0 = 255.255.252.0
