Sata Driving? Normal or Strong?

[osalcido]

Hi I just got an Asrock 939 dual-sataII mobo and I was wondering what setting the Sata driving mode in BIOS to either Normal or Strong does?

 

[unhappy_mage]

this one? I don't see anything in the manual about it. In any case, that'd be the best place to start. It's usually somewhere on the manufacturer's website.

That doesn't sound like anything officially part of the spec; I'd leave it at the default.

 

[TeeJayHoward]

A guess, and nothing more, but it may change the bus between SATA 3Gb/s (Often mistakingly called SATA-II or SATA 2) and SATA150?

Edit: Google shows that sometimes you have to have SATA driving set to "strong" in order for the mobo to reconize certain drives?

 

[UICompE02]

This is just a guess since I've never heard of "strong SATA" mode...

But I wonder if it is related to the fact that the SATA physical layer specifications actually include three different subsets. There are technically 6 different SATA physical layer specifications right now: SATA gen 1i, SATA gen 1m, SATA gen 1x, SATA gen 2i, SATA gen 2m, SATA gen 2x. The differences between the standards lie in the amplitude of the signal (drive strength or voltage) and the preemphasis (or precompensation or deemphasis as it is also called depending on how it's implemented).

The "i" standards are intended for internal, directly connected drives, the "m" standard is designed for internal, mid-length backplane connections, and the "x" standard is for external connections. As you can guess the "i" settings would have the lowest drive strength and preemphasis, "m" would be in the middle, and "x" is the highest.

My guess is your motherboard is offering you the option to switch between "i" and either "x" or "m". If this is the case, I'd recommend leaving it at the default, or lower strength mode unless you are actually connecting to a backplane or external device. Using a drive strength that is too high might work in the short time, but in the long run you may destroy the receiver due to electro-migration or electrical overstimulation.

(I've been staring at SAS/SATA and PCI-E signalling on oscilloscopes WAY more than I'd like to think about lately...)

 

[TeeJayHoward]

This is just a guess since I've never heard of "strong SATA" mode...

But I wonder if it is related to the fact that the SATA physical layer specifications actually include three different subsets. There are technically 6 different SATA physical layer specifications right now: SATA gen 1i, SATA gen 1m, SATA gen 1x, SATA gen 2i, SATA gen 2m, SATA gen 2x. The differences between the standards lie in the amplitude of the signal (drive strength or voltage) and the preemphasis (or precompensation or deemphasis as it is also called depending on how it's implemented).

The "i" standards are intended for internal, directly connected drives, the "m" standard is designed for internal, mid-length backplane connections, and the "x" standard is for external connections. As you can guess the "i" settings would have the lowest drive strength and preemphasis, "m" would be in the middle, and "x" is the highest.

My guess is your motherboard is offering you the option to switch between "i" and either "x" or "m". If this is the case, I'd recommend leaving it at the default, or lower strength mode unless you are actually connecting to a backplane or external device. Using a drive strength that is too high might work in the short time, but in the long run you may destroy the receiver due to electro-migration or electrical overstimulation.

(I've been staring at SAS/SATA and PCI-E signalling on oscilloscopes WAY more than I'd like to think about lately...)

Wow. Interesting! Any chance you could toss me a link to some further information on this subject? I've never looked deeper than bus transfer speeds.

 

[unhappy_mage]

Here's the spec for 1.0a. More here. It's pretty dense reading, but at the same it's a concise and precise description of how to build a SATA device.