Two WD5000AAKS but one is slower than the other


#1

Hi…

My pc has 3 internal hard drives WDC Blue:

1x WD3200AAJS (OS & Apps) + 2x WD5000AAKS (Storage).

The first of 500GB was bought 2 years ago and the other was bought 2 months ago.

Today I was curious with HD Tune software, it shows that old hard drive is slower than newer hard drive.

In fact, the 320GB’s drive is faster than that 500GB old drive.

(http://img7.imageshack.us/i/bench320.jpg/)] (http://img718.imageshack.us/i/info320.jpg/)]

(http://img822.imageshack.us/i/bench500.jpg/)] (http://img529.imageshack.us/i/info500.jpg/)]

Any idea of why is that?
It will be worthwhile if set up Raid O with these two 500GB drives?
How can I make that drive faster?


#2

lol

that is normal

the newer drive has a newer density in the platters

for example

my wd5000aaks from 2007 has been built with platters of 166 gb each

if i buy another now will be only one platter of 500 gb

do the math… old 3 platters, new one only 1 platter

more information in the same space = more speed reading :slight_smile:

the old drive should Weight more than the new drive…

my drive has the same results that your old drive

but acessing the files is more quick

i will send the print later


#3

If drive A has a data density (bits per square inch) that is four times greater than drive B, then we could expect that A would have twice as many tracks per inch as B, and twice as many bits (or sectors) per track.

The data rate is …

(sectors / track) x (bytes / sector) x (rotations per second)

I expect that your WD5000AAKS-00V1A0 drive would have a single disc with a density of 500GB per platter.

Without knowing anything about your WD5000AAKS-75YGA0 drive, we would expect that its data density would be …

500 x (79.6 / 131.4)^2 = 183GB per platter.

So this would suggest that it has 3 platters.

Similarly for the 320GB drive, its data density is …

500 x (105.9 / 131.4)^2 = 325GB per platter.

So this would make it a single platter model.

BTW, I’m assuming that all drives rotate at the same speed, ie 7200RPM.


#4

here it is the pictures


#5

OK, thanks for explain it   :wink:

one last question:

if I set up a RAID 0 with these 500GB drives (new & old) … how will be the resulting performance?

will be like 2 old drives, like 2 new drive, or something in between?

I mean… it could be better than 320GB drive I’m using now as main dirve or not?

Thanks again.-


#6

i am almost sure that the new drive will be limited by the performance of the older one :confused:

but wait for another response