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>> That's true. But assuming we want, say, a normal "double precision"
>> floating point number, how many clock cycles would you estimate it takes
>> to operation on? A dozen? A hundred?
>
> A lot. I don't believe *any* existing program for those processors
> does double precision floating point calculations.
You're probably right about that. (Just moving 8 bytes around has to
take a minimum of 8 instructions, before you *do* anything to those
bytes.) Just wanted to make it a like-for-like comparison. ;-)
> As he said, I don't think the term FLOPS even applies if floating point
> calculations are done in software instead of in hardware.
Floating-point operations per second. Does it matter *how* it does them?
Surely the important point is how many of 'em it can do.
>>> Both had a variable instruction set that took a variable amount of
>>> cycles to execute and therefor the number of instruction processed
>>> depended on the program and especially on the addressing modes used.
>
>> I thought this was true for *all* processors?
>
> No. The idea with RISC processors is that each opcode has the same size
> and takes exactly 1 clock cycle to execute.
Interesting. I was under the impression that processors such as the
Pentium can execute multiple instructions in parallel, and therefore
several instructions can reach the "completed" stage in a single given
clock cycle, but that each individual instruction still takes multiple
cycles from start to finish.
>> Now, anybody have any clue "how big" the numbers are for less ancient CPUs?
>
> For Intel processors it depends a lot on the executed program and the
> processor. With the 486 you might get something close if you divide the
> clockrate with 1.5 (or something like that). With the Pentium and newer
> it becomes very complicated (because the newer Pentiums have whacky things
> like parallel pipelines and out-of-order execution).
I'm only trying to figure out "how many zeros" are in the number, if you
see what I mean...
Is it 10 MIPS? 100? 1,000? 1,000,000??
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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