Analog Devices Blackfin, Getting Started

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Benchmarks Against Other Processors
1-26 Getting Started With Blackfin Processors
Benchmarks Against Other Processors
When evaluating processors, it can be confusing to look at data sheets and
compare the specifications. We recommend that you refer to accepted
industry-standard benchmarks like BDTI, Dhrystone, Whetstone, and
nbench.
L
The Dhrystone, Whetstone, and nbench benchmarks run under
the Linux platform.
The benchmarks are presented in the following sections.
Dhrystone
The Dhrystone benchmark was designed to test performance factors
important to non-numeric systems programming (operating systems,
compilers, word processors, and so forth). It is notable in that:
• It contains no floating-point operations.
• A considerable percentage of time is spent in string functions mak-
ing the test very dependent upon the way such operations are
performed (for example, by in-line code, routines written in assem-
bly language, and so on), making it susceptible to manufacturers
“tweaking” of critical routines.
• It contains hardly any tight loops so in the case of very small
caches, the majority of instruction accesses are misses; however, the
situation changes radically as soon as the cache reaches a critical
size and can hold the main measurement loop.
• Only a small amount of global data is manipulated (as opposed to
Whetstone).