Expert storage help please!

Quakemz

Honorable
Dec 10, 2013
657
0
11,160
So my build has 3 storage devices:

SSD-Corsair Force GS 128GB via SATA3
SSHD-Seagate 2TB via SATA3
HDD-WD 1TB Caviar Blue 7200rpm via SATA2

I recently moved a folder containing 13 files, totaling 30GB~ between all my drives to see the the different speeds. I was very shocked.

From HDD to SSHD the transfer stayed very close to 150mb/s the entire time.
From SSHD to SSD the transfer started a around 180mb/s, then dropped to about 140mb/s for the remaining 90%~
From SSD to HDD the transfer started around 400mb/s for the first 10%, then dropped to a stupid low of 120mb/s for the remainder.

Overall these speeds seem insanely wrong. SSDs and SSHDs are supposed to have a serious impact on speed. Any ideas on what is happening?
 
Solution
With large amounts of data the limiting factor usually ends up being the hard drives writing or reading speed.
If those numbers are Bytes instead if bits then they seem about normal for me.

HDD to SSHD is limited by the speed of the HDD, which is about 150MB/s
SSHD to SSD transfer is the same, the small SSD part probably didn't contain your files or only parts of the and the 140MB/s seems normal
SSD to HDD the transfer started at the speed of your SSD, but your HDD can only write data so fast so as soon as the memory cache for your HDD filled up the numbers dropped to 120MB/s which once again is pretty normal for a HDD limiting you.

So from what i can see things are about what you would expect. The major benefit for the SSD is...

rvilkman

Distinguished
With large amounts of data the limiting factor usually ends up being the hard drives writing or reading speed.
If those numbers are Bytes instead if bits then they seem about normal for me.

HDD to SSHD is limited by the speed of the HDD, which is about 150MB/s
SSHD to SSD transfer is the same, the small SSD part probably didn't contain your files or only parts of the and the 140MB/s seems normal
SSD to HDD the transfer started at the speed of your SSD, but your HDD can only write data so fast so as soon as the memory cache for your HDD filled up the numbers dropped to 120MB/s which once again is pretty normal for a HDD limiting you.

So from what i can see things are about what you would expect. The major benefit for the SSD is accessing lots of small files, not so much transfering large files. Obviously it is still good at that, but not my as large of a margin.
 
Solution

RealBeast

Titan
Moderator
Nope, those speeds sound like what I would expect if you understand how each works.

 

FireWire2

Distinguished

Yeap that is normal from Spindle device... If you have SSD to SSD then you will see 400MB/s sustain.

 

RealBeast

Titan
Moderator
Looks like the votes are running -- wait make that four votes -- that you are getting what is expected.

The SSHD only has 8GB of NAND, a Caviar Blue is not a very fast drive, the only thing in there that can really move data is your SSD unless you fill it past 80-90%, then it too will take a performance hit.
 


Advertised speeds for the 1TB Caviar Blue are up to 150MB/s, so your file transfer speeds are normal. http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771436.pdf



Average speeds from your SSHD are from 156MB/s to 190MB/s, with a burst speed of 210MB/s. Your transfer speeds are normal to maybe slightly below normal. http://www.seagate.com/www-content/product-content/barracuda-fam/desktop-sshd/en-us/docs/desktop-sshd-data-sheet-ds1788-2-1308us.pdf



Your transfer speeds are slightly below normal. The 400MB/s for the 1st 10% was the data that was in your HDD's cache buffer. Once the data in the cache was exhausted then the rest of the data was processed by the Read/Write heads of your HDD.
120MB/s is a little low; it should have been around 150MB/s.


 

Quakemz

Honorable
Dec 10, 2013
657
0
11,160
I appreciate it everyone. I guess I was just a little dumbfounded. I was expecting data transfer to be much quicker between the SSD and SSHD. But I guess I just didn't really do enough research.
 

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