SATA 2 HDD Transfer Speed

[ybriK]

I've never benchmarked my HDD ever since I built my PC but got curious on upgrading some of my PC's parts in the future. I downloaded and used the program CrystalDiskMark, from what I've been researching and reading SATA 2 provides 3Gbps which is around 200-300MB/s. However CDM displayed this data and was suprised... I'm no HDD/SSD expert but I understand some of the hardware components inside and what they are suppose to do, however can someone insight me as to why I'm getting these speeds as opposed to the 'promised' transfer rate of 200-300MB/s??? I also tested out my USB 3.0 (5Gbps) 1TB external HDD and that achieved 100-150 MB/s Write & Read.

 

-----------------------------------------------------------------------
CrystalDiskMark 3.0.2 x64 © 2007-2013 hiyohiyo
                           Crystal Dew World : http://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [sATA/300 = 300,000,000 byte/s]

           Sequential Read :    86.566 MB/s
          Sequential Write :    84.610 MB/s
         Random Read 512KB :    24.173 MB/s
        Random Write 512KB :    42.334 MB/s
    Random Read 4KB (QD=1) :     0.259 MB/s [    63.1 IOPS]
   Random Write 4KB (QD=1) :     0.890 MB/s [   217.4 IOPS]
   Random Read 4KB (QD=32) :     0.528 MB/s [   128.9 IOPS]
  Random Write 4KB (QD=32) :     1.002 MB/s [   244.7 IOPS]

  Test : 1000 MB [C: 87.7% (408.2/465.7 GB)] (x3)
  Date : 2013/08/11 18:35:42
    OS : Windows 7 Home Premium Edition SP1 [6.1 Build 7601] (x64)
 

[WoodenMarker]

Your hdd is likely not fast enough to fully saturate the sata connection. 

The transfer rate is the port's capability but not the drive.

 

It looks normal.

[ybriK]

Your hdd is likely not fast enough to fully saturate the sata connection. 

The transfer rate is the port's capability but not the drive.

 

It looks normal.

If I did have a SATA 3 port Mobo what speeds in theory should I be hitting?

[WoodenMarker]

If I did have a SATA 3 port Mobo what speeds in theory should I be hitting?

It would be the same. Your hdd is not fast enough to saturate the port. 

[ybriK]

It would be the same. Your hdd is not fast enough to saturate the port. 

Ah I think I understand it now, I was just thinking about how some SSDs are hitting around 500-600 MB/s for SATA 3 ports because of the fact they are flash memory. I was thinking of upgrading to a WD Black 1TB since I prefer storage over speed (ext. HDD almost full).

[WoodenMarker]

Ah I think I understand it now, I was just thinking about how some SSDs are hitting around 500-600 MB/s for SATA 3 ports because of the fact they are flash memory. I was thinking of upgrading to a WD Black 1TB since I prefer storage over speed (ext. HDD almost full).

It's not worth paying the extra for the caviar black imo. Something like a caviar blue or seagate barracuda is cheaper and isn't far behind in speed.

If you need the storage, grab a blue or barracuda. If you want speed, a ssd makes a world of difference. Not even the fastest hdds touch the speed of any decent ssd.