SATA question

dragoran dragoran at feuerpokemon.de
Wed Feb 1 13:45:18 UTC 2006


Ivan Gyurdiev wrote:

>
>
>>> It's nice to know my SATA II drive is so much superior :)
>>
>>
>> If the rpm, number of platters, and data encoding stay the same, so 
>> will the performance, broadly speaking, 8MB or 16MB of cache will 
>> only have an effect if you're doing reading that fits a certain 
>> pattern, and as we've seen the physical disk couldn't even half fill 
>> an ATA133 interface (let alone SATA, or SATA II) only cache reads can 
>> do that.
>
> Why are my cache reads so much slower than yours (by a factor of 2)?
> A friend of mine has SATA I, with 1800 MB/s cached reads, which is 
> also much better.
>
>
 /sbin/hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   5428 MB in  2.00 seconds = 2713.83 MB/sec
 Timing buffered disk reads:  174 MB in  3.00 seconds =  58.00 MB/sec
-----------------
/sbin/hdparm -Tt /dev/hda

/dev/hda:
 Timing cached reads:   5532 MB in  2.00 seconds = 2765.83 MB/sec
 Timing buffered disk reads:   90 MB in  3.01 seconds =  29.92 MB/sec
----
this has more to do with the cpu/memory speed, but nothing with the 
interface
I have a AMD64 with DDR474Mhz Ram and getting the speeds listed above.




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