SATA2/3 Does a mechanical HD saturate the SATA 2 connection?

[Aurimas]

Slowly putting together a new pc.

Some of the old components that are coming over to save money include a WD Black 1tb. (and things like the power supply, case, etc. not the focus of this post).

I know that the HD is SATA2. What I'm wondering is if it saturates the connection anyway? Would a SATA3 version be quicker?

Guess I'm wondering how quickly and at what priority I should replace the HD.

Thanks in advance.

[llDemonll]

No, a mechanical drive will not saturate a SATA 2 connection

[Biernot]

No, a mechanical drive will not saturate a SATA 2 connection

To elaborate further with some data:

SATA 2 has a maximum speed of 300 MByte/sec
SATA 3 has a maximum speed of 600 MByte/sec

Speeds for mechanical hard drives are roughly the following:
- Peak R/W performance for non-fragmented data in the outer sectors of a platter: up to 150 MByte/sec
- Sustainable R/W performance for non-fragmented data: around 100 MByte/sec
- real life sustained speed for lightly fragmented data: 50-80 MByte/sec
- real life speed for average daily use: anywhere between 5 and 50 MByte/sec

Even if your SATA interface would be capped at 100 MByte/sec, you would not notice the difference with a mechanical hard drive.
Opposed to modern SATA-3 SSDs, which can usually reach speeds above 500 MByte/sec. But even then you would barely notice the difference to SATA-2.

[Fluorescent0]

Even if your SATA interface would be capped at 100 MByte/sec, you would not notice the difference with a mechanical hard drive.
Opposed to modern SATA-3 SSDs, which can usually reach speeds above 500 MByte/sec. But even then you would barely notice the difference to SATA-2.

You would on some HDDs. Single platter caviar blues have ~130MB/s read/write speeds. Not even close to saturating sata 2 though.

[vesseblah]

To elaborate further with some data:

And TL;DR version of the above: no current mechanical HDD on the market can cap even SATA1 speed, so it doesn't matter one bit if you use SATA2 or SATA3 (or even SATA1) with those. SSDs are different matter entirely, and are very close to capping even SATA3 connectors.

- - - Updated - - -

You would on some HDDs. Single platter caviar blues have ~130MB/s read/write speeds. Not even close to saturating sata 2 though.

No. Only in empty disc it can reach that kind of speeds. On a full and slightly fragmented disc (in real world use) the speed drops to 70-90MB/s.

[Aurimas]

Thanks guys.