Re: 32bit vs 64bit ?

Andre Fernandes Vincent <avincent_at_unisys.com.br> wrote:
>
> pbertigl_at_io.com (Paolo Bertiglia) wrote:
> >Digital's brochure about their XAP servers and the 64 bit OpenVMS claim an
> >houndredfold advantage for a database (Rdb & Oracle) that use a 64 bit Very
> >Large Memory model over the same but only 32 bit software.
> >
> >I understand that you have a much larger address space in 64 bit but how this
> >can be translated in a so big performance advantage?
> >
> >Thanks in advance for every answer.
> >
>
> I'm not a HW expert, so expect to get better ansywers then mine!
> But, as far as I'm concerned, a large address space is not the
> only consequence of a 64 bit architecture. I thinks this
> architecture means 64 bit transfers between Memory and CPU, in
> one clock "tic" (or cycle). I think this should also mean 64 but
> registers inside the CPU, maybe brimging some performance
> improvements.
>
> Continuing the guessings, maybe this effect is not so big,
> because in a 64 bit archictecture an integer should use
> 64 bits in a register, as in a 32 bit, it should use 32.
>
> Is this last paragraph "too" wrong? Help us, Hardware people!
>

Hi,

In any current DBMS, squeezing terabyte databases into the (16 or 32) byte address space of current processors takes much of the processing time. A 64 bitaddress space can map around 10 to the 19'th bytes directly and that large overhead is gone. I have written several DBMS' and it saves a lot of work!

Tom Received on Thu May 09 1996 - 00:00:00 CEST