The compiler has to group parallel instructions and needs to consider pipeline constraints.
The problem of instruction level power characterization of -issue VLIW processor is where is the number of instructions in the ISA and is number of parallel instructions composing the VLIW [30].
The ILPA-based methods have some drawbacks, one of these drawbacks is that the number of current measurements is directly related to the number of instructions in the Instruction Set Architecture (ISA) and also the number of parallel instructions composing the very long instruction in the VLIW processor.
These scenarios vary the dispatch rate (number of fetch packets divided by the number of execution packets) from to. Figure 6 shows screen shots of the scenarios to vary the dispatch rate, where the pipe symbols indicate parallel instructions, that is, the first instruction without together with the successor instructions with is executed in the same clock cycle.
The idea becomes possible with recent high-end VLIW processors, where we have to issue parallel instructions computing the twiddle factors in the masked time; however, it requires proper scheduling and low-level control on the execution pattern to be done successfully.
The speed increase is accomplished through the use of BLAST-like heuristics to quickly identify promising matches through ungapped alignment and by using vector parallel instructions, such as SSE2, on Intel microprocessors.
To get past this barrier, Intel and Hewlett-Packard are proposing a new style of computing, which they have called EPIC, for explicitly parallel instruction computing.
But the Itanium 2 is not based on Intel's core x86 technology but instead uses a new scheme called EPIC (Explicitly Parallel Instruction Computing).
For mapping the present serial instruction to parallel instruction of multi-GPU cluster, the computing units are dispatched by the unified communication platform, and the cell and controller can have two-way communications, as shown in Fig. 7.
With Itanium 2, Intel is walking away from the x86 instruction set, which has been at the core of every Intel PC microprocessor since the 1980s, in favor of a new instruction set called EPIC (Explicitly Parallel Instruction Computing) created by Hewlett-Packard.
IA-64 is Explicitly Parallel Instruction Computing (EPIC) architecture, versus RISC (Reduced Instruction Set Computing – like the Alpha and UltraSPARC) or a CISC (Complex Instruction Set Computing – like Pentium III) and depends on a compiler, which controls how efficiently the chip will perform its calculations.
