List of fake vs. real SATA drives.

Stephen Montgomery-Smith stephen at math.missouri.edu
Tue Nov 23 00:19:18 GMT 2004


Søren Schmidt wrote:
> Stephen Montgomery-Smith wrote:
> 
>> Thomas Wolf wrote:
>>
>>> Stephen Montgomery-Smith <stephen at math.missouri.edu> schrieb:
>>>
>>>> FUJISHIMA Satsuki wrote:
>>>>
>>>>> Currently native SATA drives are still not so popular. There are:
>>>>
>>>>
>>>>> Seagate Barracuda ATA V, 7200.7, 7200.8
>>>>
>>>>
>>>> I have one of these, and I am really impressed by its performance.  
>>>> I added one to my computer, which came with a Maxtor 6Y080L0.  My 
>>>> main disk intensive operation is creating the CTM deltas (as in CTM 
>>>> which is an alternative to CVSUP for people behind unfriendly 
>>>> firewalls).  The performance difference was somewhat collosal, as in 
>>>> something like 3 times faster.  To be honest, I am still at a loss 
>>>> to explain why the Seagate did so very much better - maybe it is the 
>>>> 8M cache as compared to the 2M cache.  The Seagate 7200.7 had 
>>>> similar performance to a Seagate 160MHz SCSI drive that I have on 
>>>> another computer.
>>>
>>>
>>> Ah, please tell me more about it, is this a ST3120827AS?
>>> (I would need the exact PartNo.) What controller dou you have and 
>>> finally, on which version of FreeBSD?
>>>
>> ST380013AS with Intel ICH5 SATA150 controller and FreeBSD 4.10-Stable. 
>> The kernel reports that it is running at UDMA33, but the actual 
>> performance seems much better than that.
> 
> 
> Hold on right there, the ST380013AS is a Barracuda V 7200.7 device and 
> does not do any form of tagging, neither does the ICH5 support it. You 
> are just enjoying the stock speed of modern (S)ATA gear :)
> Oh, and 4.x has no notion of SATA it only works on controllers that can 
> emulate the old ATA way of things. This is means that the ATA33 speed 
> isn't whats used as SATA v1 always runs at 150MB/s, just 4.x has no way 
> of telling.
> 

But the stock speed of modern SATA gear just seems so good.  I did a 
google on both the Seagate driver and Maxtor drives that I had in my 
computer, and the specs seemed about the same except for the cache size, 
yet the performance of the Seagate was just so very much better.  I am 
still at a loss to really explain why.  (The Maxtor was a ATA133 
although the controler only did ATA100.)  Can anyone suggest to me why 
the Seagate was so very much better?

Stephen


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