Re: Version after Version


"ProfitMaxTrading.com" <nospam@xxxxxxxxxx> wrote in message
news:49O7f.113$0M1.51@xxxxxxxxxxxxx
> Now I've been long removed from the architecture of the machine, but
> isn't it correct to say that with a 64 bit processor, we're talking about
> being able to load the equivalent of two 32 bit words with a single clock
> cycle? That would suggest that, although the clock speed is the same with
> the 32 and 64 bit processor (one not faster than the other), the latter
> would process twice as many bits of data for each clock cycle. Thus this
> would suggest that you can 'process' twice as much within a given time.

In days of old the native word size of a cpu indicated the bus width. Its
not so straightforward in modern architectures. Actually, IIRC, an early
example of this breakdown was the 80186 which had an 8-bit bus and a 16-bit
cpu. I don't think one can assume that a 64-bit cpu is going to load
64-bits in a single cycle, even if we are talking about L1 cache.

In theory 64-bit should generally be faster, but lots of software revisions
are likely required to see this in practice. A program that uses 32-bit
integers, for example, may well end up paying a penalty for half-word
increments and arithmetic. Given that the bulk of modern software mostly
does string manipulation of one form or another, (last stat I recall puts
it at roughly 60% of all business processing), its likely that the move to
64-bit on the desktop will bring measurable, but marginal, improvements.


.

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