[X4U] 64 vs 32 was...Re: move to Intel

[Stroller]

On Jun 15, 2005, at 8:00 pm, Alec McKenzie wrote:
>
> In recent years personal computers have progressed in many ways. 
> Processors are faster, RAM and hard drive capacities are greater. Yet 
> the speed of the hard drive seems to have gone into reverse. My 
> Macintosh is six years old this month, and its hard drive runs at 
> 10,000 rpm. Yet in the present Macintosh range the fastest I can see 
> is 7,200 rpm. Why this decline, I wonder?

What data transfer rates do the two drives support, though?

Although I'm sure there were some very fast SCSI drives about 6 years 
ago, I'm sure the average drive has many more bits per inch nowadays. 
Suppose a 7,200rpm drive is reading twice as many bits per revolution 
than an older 10krpm drive - surely it can therefore read 40% more data 
in the same time, even though it is "going more slowly"?

I don't know the details on how data density actually affects speed, 
but ZDnet says that "platter density ... doubled annually from about 
1997 to about 2001" [1], and I'm sure a new drive won't actually be 
slower (in terms of useful data transfer) than the one in your 6 
year-old Mac - it wouldn't make sense for manufacturers to sell drives 
that are progressively worse each year.

Stroller.



[1] http://news.zdnet.com/2100-9584_22-5061923.html