Slow Transfer Speed from SSD to HDD over SATA 3.

[thecynicalmonk]

So I was transferring roughly 60GB from my SSD to my HDD and realized it was only transferring at a meager 150 MBps. This is honestly the first time i really paid any attention to the transfer speed and it confused me. As we all know 150 MBps is SATA 1 speeds, and my HDD/SDD and Motherboard all are SATA 3. (Yes, I do have AHCI turned on in BIOS on all SATA ports)

Furthermore, will I only see true SSD SATA 3 speeds when transferring from SSD to SSD? Because it would only make sense that when using two different storage devices with varying transfer speeds, your bottleneck would be the slowest device.

Thanks for taking the time to read! (My build is in my profile)

 

[popatim]

when transferring anything, you will always be limited to the speed of the slowest device in the chain.

HDD's slow down with files sizes. Their fastest speeds are large sequential files that require very little head movement. If you look at their 4k random speed you may be in for a shock. Moving a few thousand 4k files will seem like eternity. LoL

the St1000dm003 is capable of 200MB/s sequentially yet only 600KB/s to 1MB/s in random - for example.
This is where an SSD really shines since most users rarely operate with sequential files.

 

[thecynicalmonk]

So would you say that 150 MBps from my SSD to HDD is normal then? No cause for worry?

And just out of curiosity, would I need to transfer from one SSD to another to see true SSD transfer speeds?

 

[giantbucket]

150MB/s is a fairly normal hard drive write speed for large files. if you're copying thousands of tiny files, that speed is going to tank by a factor of 10 due to all the overhead/housekeeping associated with each file.

copying from SSD to SSD is (currently) silly. most folks use one SSD for their system, and have HDD for everything that isn't Windows core OS stuff. but yeah, copying from SSD to SSD will be faster - but again only for large files. for smaller ones, it'll tank again but less so.

 

[thecynicalmonk]

Thanks for alleviating my confusion. The more you know ...