[G4] Drives?

[Doug Burton]

On Jan 31, 2008, at 11:47 AM, John Niven wrote:

> Doug,
> What are you defining as a Mb?
>
> There is a difference between Mbytes and Mbits. A byte
> is 8 bits.
>
> So in theory 133Mbytes per second is equivalent to
> 1064Mbits per second (=1.064Gbits per second). This is
> less than 1.5Gbits but there are overheads in the bit
> coding which mean that these two numbers are not
> exactly equivalent. THAT's why it's confusing!
>
> I had read that in practice ATA133 ~= SATA150.
>
> Anyway I would rather use SATA because of the better
> cabling and airflow, never mind the speed.
>
> John
>
> --- Doug Burton <slugg0 at embarqmail.com> wrote:
>
>>> ATA133 = 133Mbytes per second.
>>> SATA = 1.5Gbits per second.
>>
>> I find this a bit misleading in that you state the
>> drive speeds in two
>> different formats.  Why not just tell it like it is
>> and say:
>>
>> ATA133 = 133 Mb per second
>> SATA = 150 Mb per second

Exactly why I said it was confusing to state PATA as Mbytes and SATA  
as Gbits.  When you look at the true speed difference you should state  
the terms in the same format, Mbytes to Mbytes or Gbits to Gbits.   
Your statement following the speed stats, "I believe these two are  
comparable in throughput.", was indeed correct.

And yes the true advantage to using SATA (150) drives is the cabling.   
Now when you move up to SATA (300) or SATA II as it's sometimes  
referred to, the speed is a greater factor.  Unfortunately I don't  
know of any Mac interface cards available for this faster SATA  
standard yet.

Just a message from Doug...