Consider a non-pipelined processor operating at 2.5 GHz. It takes 5 clock cycles to complete an instruction. You are going to make a 5-stage pipeline out of this processor. Overheads associated with pipelining force you to operate the pipelined processor at 2 GHz. In a given program, assume that 30% are memory instructions, 60% are ALU instructions and the rest are branch instructions. 5% of the memory instructions cause stalls of 50 clock cycles each due to cache misses and 50% of the branch instructions cause stalls of 2 cycles each. Assume that there are no stalls associated with the execution of ALU instructions. For this program, the speedup achieved by the pipelined processor over the non-pipelined processor (round off to 2 decimal places) is _____.

The instruction pipeline of a $$RISC$$ processor has the following stages: Instruction Fetch $$(IF),$$ Instruction Decode $$(ID),$$ Operand Fetch $$(OF),$$ Perform Operation $$(PO)$$ and Writeback $$(WB).$$ The $$IF,$$ $$ID,$$ $$OF$$ and $$WB$$ stages take $$1$$ clock cycle each for every instruction. Consider a sequence of $$100$$ instructions. In the $$PO$$ stage, $$40$$ instructions take $$3$$ clock cycles each, $$35$$ instructions take $$2$$ clock cycles each, and the remaining $$25$$ instructions take $$1$$ clock cycle each. Assume that there are no data hazards and no control hazards.

The number of clock cycles required for completion of execution of the sequence of instructions is ______.

Suppose the functions $$F$$ and $$G$$ can be computed in $$5$$ and $$3$$ nanoseconds by functional units $${U_F}$$ and $${U_G},$$ respectively. Given two instances of $${U_F}$$ and two instances of $${U_G},$$ it is required to implement the computation $$F\left( {G\left( {{X_i}} \right)} \right)$$ for $$1 \le i \le 10.$$ Ignoring all other delays, the minimum time required to complete this computation is _____________ nanoseconds.

Consider a $$3$$ $$GHz$$ (gigahertz) processor with a three-stage pipeline and stage latencies $${\tau _1},{\tau _2},$$ and $${\tau _3}$$ such that $${\tau _1} = 3{\tau _2}/4 = 2{\tau _3}.$$ If the longest pipeline stage is split into two pipeline stages of equal latency, the new frequency is ____________ $$GHz,$$ ignoring delays in the pipeline registers.