Does SATA II = 300mb/s or 3gb/s?

[Schfifty Five]

I am looking to switch over to SATA drives and raiding them, but I'm a little confused with the SATA I, II, etc.

I know SATA I = 150mb/s, but I am seeing SATA II as 300mb/s and some as 3 gb/s.

Is SATA II both?

Thanks.

Sorry if this has been posted many times before.

 

[Kaido]

See the SATA II section here, should clear things up:

http://en.wikipedia.org/wiki/SATA

 

[dBTelos]

SATAI = 150MB/s = 1.2Gb/s
SATAII = 300MB/s = 3Gb/s

B = Byte
b = Bit
/s = per second

 

[Schfifty Five]

Originally posted by: dBTelos
SATAI = 150MB/s = 1.2Gb/s
SATAII = 300MB/s = 3Gb/s

B = Byte
b = Bit
/s = per second

If they doubled from 1.2Gb/s, how come it's not just 2.4Gb/s

But thanks for the clarification!

 

[Schfifty Five]

Originally posted by: Kaido
See the SATA II section here, should clear things up:

http://en.wikipedia.org/wiki/SATA

Cool, thanks that helps!

 

[dBTelos]

Originally posted by: Schfifty Five

Originally posted by: dBTelos
SATAI = 150MB/s = 1.2Gb/s
SATAII = 300MB/s = 3Gb/s

B = Byte
b = Bit
/s = per second

If they doubled from 1.2Gb/s, how come it's not just 2.4Gb/s

But thanks for the clarification!

SATA I is only a 80% efficient. 80% of 1.5Gb = 1.2Gb hence 1.2Gb/s

 

[Schfifty Five]

Originally posted by: dBTelos

Originally posted by: Schfifty Five

Originally posted by: dBTelos
SATAI = 150MB/s = 1.2Gb/s
SATAII = 300MB/s = 3Gb/s

B = Byte
b = Bit
/s = per second

If they doubled from 1.2Gb/s, how come it's not just 2.4Gb/s

But thanks for the clarification!

SATA I is only a 80% efficient. 80% of 1.5Gb = 1.2Gb hence 1.2Gb/s

OIC, so same idea with SATA II, 80% eff. and all....

 

[Pariah]

Originally posted by: dBTelos
SATAI = 150MB/s = 1.2Gb/s
SATAII = 300MB/s = 3Gb/s

B = Byte
b = Bit
/s = per second

SATA I is 1.5Gb/s interface throughput, 150MB/s data throughput.
SATA I/O is 3Gb/s interface, 300MB/s data.

 

[Pariah]

Originally posted by: Schfifty Five

Originally posted by: dBTelos
SATAI = 150MB/s = 1.2Gb/s
SATAII = 300MB/s = 3Gb/s

B = Byte
b = Bit
/s = per second

If they doubled from 1.2Gb/s, how come it's not just 2.4Gb/s

But thanks for the clarification!

Because dBTelos is confusing his numbers. 300MB/s for SATA I/O is the theoretical data throughput, but that does not equal 3Gb/s, which is the theoretical interface throughput which includes an additional 2 bits of information for CRC and other stuff for every 8 bits of data. 300MB/s equals 2.4Gb/s as you pointed out. So, to stay consistent, he should have put 2.4Gb/s.

 

[omniphil]

Why does it matter when no HD can transfer data off the platter any faster than around 80mb/s?

Even the newest perpendicular drive from seagate thats 15k rpms hits just over 100mb/s transfer...

The interface is not the bottleneck, the platter and heads are...

 

[MNOB07]

Originally posted by: omniphil
Why does it matter when no HD can transfer data off the platter any faster than around 80mb/s?

Even the newest perpendicular drive from seagate thats 15k rpms hits just over 100mb/s transfer...

The interface is not the bottleneck, the platter and heads are...

two words:

RAM drive

🙂

 

[Schfifty Five]

Originally posted by: omniphil
Why does it matter when no HD can transfer data off the platter any faster than around 80mb/s?

Even the newest perpendicular drive from seagate thats 15k rpms hits just over 100mb/s transfer...

The interface is not the bottleneck, the platter and heads are...

All I was asking was for a clarification of the terms/numbers that are listed.

Yeah you don't need to state the obvious about bottlenecks and stuff....everyone knows that.

But since SATA will be the future, and price is equal to PATA, AND i do need the extra space, why not just get SATA then? It only makes sense.

 

[Pariah]

Originally posted by: omniphil
Why does it matter when no HD can transfer data off the platter any faster than around 80mb/s?

Even the newest perpendicular drive from seagate thats 15k rpms hits just over 100mb/s transfer...

The interface is not the bottleneck, the platter and heads are...

Because the second generation of SATA allows for more than one drive to be attached to the same controller.

 

[RichUK]

Originally posted by: Pariah

Originally posted by: omniphil
Why does it matter when no HD can transfer data off the platter any faster than around 80mb/s?

Even the newest perpendicular drive from seagate thats 15k rpms hits just over 100mb/s transfer...

The interface is not the bottleneck, the platter and heads are...

Because the second generation of SATA allows for more than one drive to be attached to the same controller.

Is that correct?

Nforce 4 has two on die SATA controllers, you can connect up 4 drives (2 per controller, with first generation drives, and it will work fine.

I am misunderstanding you or something?

 

[Pariah]

Through the use of hubs, the 2nd generation of SATA allows for more than one drive to be connected to a single port. Unfortunately, I'm not aware of any company producing such a hub yet, though they have bee demo'd at trade shows.