hpca ยป

HPCA equations

Active Power P = 1/2 C * V^2 * f * a

Yield Yield = Working Chips / Chips on Wafer

Fabrication Cost Fab Cost = Total Cost / Number of Wafers

Speedup N = Speedup(X) / Speedup(Y) = Throughput(X) / Throughput (Y) = Latency(Y) / Latency(X)

CPU Time CPU Time = # of Instructions in the progam * cycles per instruction * clock cycle time

Amdahl's Law Speedup = 1 / ((1 - Frac of Enhancement) + Frac of Enhancement / Speedup of Enhancement

Execute Time ExeTime = #Instructions * CPI * Cycle Time

CPI CPI = 1 + Mispredictions / Instructions * Penalty / Misprediction

Availability Availability = MTTF / (MTFF + MTTR)

AMAT AMAT = Hit Time + Miss Rate * Miss Penalty

AMAT AMAT = (1 - Miss Rate) * Hit Time + Miss Rate * Miss Time

Miss Time Miss Time = Hit Time + Miss Penalty

L1 miss penalty = L2 hit time + L2 miss rate * L2 miss penalty

Global Hit Rate = 1 - Global Miss Rate

Global Miss Rate = # of Misses in this cache / # of all memory accesses

Local Hit Rate = # of Hits / # of Access to this cache

Page Table Size Page Table Size = (Virtual Memory/ Page Size) * Size of Entry

RAID0 1 Disk MTTF RAID0, 1 Disk MTTF = 1 / failure rate for single disk

RAID0 N Disk MTTF RAID0, N disks MTTF = MTTF of one disk / N

RAID1 N Disk MTTDL RAID1 N Disk MTTDLN = MTTF1/N where N is the number of disks

RAID4 Write RAID4 Write = 1/2 of throughput of 1 disk

RAID4 Read RAID4 Read = (N -1) * Throughput of one disk

RAID4 MTTF RAID4 MTTF = 1(MTTF of 1 disk * MTTF of 1 disk) / (N * (N-1)*(MTTR of 1 disk)

RAID4 Data Capacity RAID4 Data Capacity = (N-10 * Capacity of 1 disk)

RAID5 Read Performance RAID5 Read Performance = N * Throughput of 1 disk

RAID5 Write Performance RAID5 Write Performance (4 Accesses/Write) = N / 4 * Throughout of 1 Disk