Thanks for the obvious answer. I wrongly assumed that LBA had properly
addressed this repeating problem.

My comment about stupid software comes from the fact that this is at
least the 3rd or 4th time this has happened. You'd think that we would
have learned by now and done exactly what you suggest, have a standard
that supports the predictable and obvious growth of storage and the
need to address it. At least the IP standard was overly generous
for it's day, but as a result it lasted over 10 years before
requiring rework (IPV6).

With SATA (serial ATA) becoming available, the opportunity to have
variable width addressing should have been addressed.
And making sectors bigger than 512 bytes would have greatly
improved throughput and media efficiently. Back in the old decades
of CP/M, floppy drives could be formatted with 256/512/1024/2048 bytes
per sector. IMS you got 25% more storage out of media formatted at 2048/per
sector and the CP/M BIOS took care of the blocking issue.

I assume that the big drives of today do this blocking/deblocking
internally anyway.

So once again we're back to having to load driver programs for our
bigger hard drives. Sheesh.

So what is the SCSI addressing limit?

Robert


Herbert Graf wrote:
>
> > > What 137GB boundary? I'm looking at buying a 160GB drive RSN.
> > > Are we STILL running into stupid software/BIOSes? 512MB, 8GB and
> > > now 137GB?
> > > R
> >
> >       IIRC the 137GB boundary is a result of LBA, which of course
> > was a patch to get more then around 500MB of storage on a hard drive.
> >
> >       It's easy math: LBA is 28 bits, biggest unsigned number
> > that 28 bits can represent is:
> >
> > 2^28 = 268 435 456 sectors
> > Each sector on an IDE disk (with very few exceptions) is 512
> > Bytes, therefore:
> > 268435456 x 512 = 137 438 953 472 bytes = 128GB (or 137GB in the
> > hard drive version of GB)
> >
> > There is an extension to LBA called LBA32 which uses 32 bits of
> > data to represent the sector. I believe to you use it you need OS
> > and BIOS support, although you might no longer need BIOS support
> > (unless your boot partition exists above the 137GB boundary, in
> > which case your bios won't see the boot partition and your system
> > won't boot!).
> >
> > As for your comment: "Are we STILL running into stupid
> > software/BIOSes?" the answer is: of course we are. And we always
> > will. The amount of storage must always be addressed. The
> > addresses must always have a finite number. Until some scheme is
> > used where the amount of bits used to represent storage is
> > encoded (and variable) we will always hit limits like this. This
> > is a fact of life.
> >
> > TTYL
>
>         Woops, minor correction, new LBA is 48 bits, not 32:
> http://www.transcendusa.com/Mem/Drv/lba.PDF
>
> Sorry bout that. TTYL
>
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