SATA-II explained

[smids]

SATA-II explained - Revised 17/4/2007

Right, there have been many posts and threads recently asking about 'SATA-II' drives. This is a small explanation of these drives and what SATA-II really is.

SATA-II was the name of the organisation set up to write the specifications of the Serial ATA 2.5/2.6 generation drives and possibly beyond. It is not the name of a new drive standard. However, since the confusion caused by manufacturers of drives naming later drives SATA-II (a practice which is now dying off), they have changed their name to SATA-IO (Serial ATA International Organisation). It is important to note that SATA-II/SATA2 does not actually exist as a new drive standard and is merely a term sometimes used (erronously) to refer to drives which support some of the later SATA features.

Here is a small FAQ regarding SATA, SATA2, SATA-II, etc:

1. How many versions of SATA are there?

- There is currently only one version of the standard simply called 'SATA'. Extensions have been added to this in various generations of the specifications (currently up to generation 2.6) and these include support features such as the 3.0Gbit/s or 300MB/s (see point 4) interface speed, Native Command Queuing (NCQ), staggered spin up to name but a few. These extensions are optional and SATA drives can support as many or few of them as they like. Several suppliers still use the term SATA-II to refer to drives which support one or more of these extensions (particulaly the 3.0Gbit/s interface speed) - contrary to the wishes of the SATA International Organisation. Other companies (Seagate, Western Digital, etc) have now dropped the term.

For a table of the Serial ATA features, please see the table at the base of this mini-FAQ.

2. Is there a different power cable for 'SATA-II'/SATA300 drives or do I need an adapter?

- All SATA drives use the same type of power cable.

3. Is there a different data cable for 'SATA-II'/SATA300 drives?

- All SATA drives use the same type of data cable, regardless of whether they support the 3.0Gbit/s interface speed or not.

4. Why are some drives/controllers listed as SATA 300MB/s whereas others are listed as SATA 3.0Gbit/s? Which one is faster?

- Both are different terms used to refer to the same controller/drive speed. The 3.0Gbit/s rating means 3 Gigabits per second and is the raw speed with which the controller/drives operate at. Due to the 8b10b coding overhead which SATA uses, the actual uncoded transfer-rate is 2.4 Gbit/s which is the same as 300 Megabytes per second. Effectively though, both terms mean the same thing. The same applies to SATA150 compared with SATA 1.5Gbit/s.

5. Will my new 'SATA-II'/SATA300 drive work on my SATA150 controller (and vice versa)?

- All SATA drives should work with all controllers. This includes SATA300 drives working on SATA150 controllers and vice versa.

NOTE: Some SATA150 controllers do not support auto speed negotiation. When using a SATA300 drive with such a controller, it is necessary to change a jumper setting on the drive to force the drive to use the 150MB/s interface speed. The best approach is often to try the drive out and to change the jumper if the drive is not being detected in the BIOS when the system is powered up. Some owners of SATA300 drives may still experience problems however as some older SATA300 drives may require a firmware flash of their drive (in which case the manufacturer will need to be contacted). These issues arose as a result of manufacturer's bridging chip and firmware conflicts. Some drives have no jumpers e.g. Hitachi and require a firmware setting to be changed - see Q7 below. In most cases however, a SATA300 drive should function fine on a SATA150 controller.

6. Will I notice a big performance increase from a SATA300 drive over SATA150 drive with, for example the following extra features: 16MB cache and NCQ?

- No. The 3.0Gbit/s transfer rate would only come into play if you had a controller which supports the full 3.0Gbit/s transfer or a RAID array with probably at least 4 disks - a single 7200RPM drive will have a maximum external transfer rate of about 58MB/s (as opposed to the 300MB/s available). Thus, in single drive configurations, SATA300 drives show no increase over SATA150 or even IDE for that matter seeing as they will all have an external transfer rate of around 55-60MB/s (7200rpm drives only).The only performance increase you will see is through the 16MB cache (should help writing and reading performance) and NCQ (Native Command Queuing) so long as your motherbard supports it. Thus, the performance increase will not be great over SATA150 drives, if at all, depending on features of the specific drive.

7. Will my SATA300 drive work out of the box at the full interface speed of 3.0Gbit/s - I have a compatible motherboard?

- Yes, for the most part. Hitachi drives are slightly different. For compatibility reasons, Hitachi default their drives to 1.5Gbit/s. To enable the 3.0Gbit/s interface speed on Hitachi's, you must download their Feature Tool and enable it from within DOS.

8. Can I run a SATA300 drive with a SATA150 drive and still get the full rate on the SATA300 drive?

- Yes. They will be on separate channels and so long as your SATA controller supports 3.0Gbit/s transfer rate, then they will run as intended. The same applies to combining drives where only one drive supports features such as NCQ as well.

9. How can I tell if my SATA300 drive is running at its intended 3.0Gbit/s, I have full support for it?

- If you have an nForce 4 board with the nF4 SATA drivers installed, the easy way is to look in Device Manager. Look at the properties of the SATA controllers under IDE ATA/ATAPI controller and there is a tab in there which displays either SATA Generation 1-1.5G for SATA150 and SATA Generation 2-2.5 (iirc) for SATA300. Otherwise, please download HDTach. Perform a quick test on the relevant drive and look at the burst speed. SATA150 will max out before 150MB/s but SATA300 will surpass this up to 300MB/s.

The actual specifications for Serial ATA drives can be found in this table:

Notice how many features are actually optional. Thus, ensure you know the actual specifications of the drive before purchasing.

Major thanks to Trippynet for re-writing the sticky to bring it up to date

 

[smids]

i have just bought a 300gig maxtor sata II drive.Will i see big performance increase?

That's a good question. What are the spec's - I'll incorporate a question much like this in the guide.

 

[smids]

The only performance increase you will see is through the 16MB cache and NCQ - Native Command Queuing - so long as your motherbard supports it. The 3.0Gbp/s transfer rate is entirely useless to yourself and would only come into play if you had a RAID array with probably at least 4 disks - a single drive will have a maximum external transfer rate of about 58MB/s (as opposed to the 300MB/s available). Thanks for posing the question though, I'll add something along those lines into the guide.

 

[smids]

Nice guide there, may be worth adding to the sticky (obviously leave it here floating for a bit to get more comments though) You may want to leave it a bit and then email werewolf and see what he says.

You got anything to add to it? Your last guide was pretty good I must say. Any comments, even stylistic?

 

[smids]

Thanks, Ken - I knew about that but forgot to add it to the guide. Will get right on it.

 

[smids]

just installed my disk maxtor 300 gig sata2

how do i get sata 2? do i use a differebt lead?

driver?

About the lead - see first post

Driver - now that is an interesting thing. SATA-II features are a hardware thing, so I doubt they can rely on drivers - however, I'm not sure say in the case of NCQ. NCQ requires both hard disk and controller support to function, but does the controller require the driver to use NCQ - can anyone answer this? e.g. in the case of nForce4. I'll innvestigate it myself. A very poignant question...

What motherboard do you have?

EDIT: I believe the situation is that you require drivers for the controller, but without this, you still get the external transfer rate and other features, though NCQ is a sticky one which I will find out about. So plug your drive in, install any drivers your controller requires e.g. nF4 users, install your chipset IDE SW drivers and this will mean that the SATA-II features are present.

 

[smids]

Best to keep this near the top . Any comments/suggestions? Come on people, I need some more feedback, this is for your benefit.

Also, as a follow up to the previous post, does anyone know the answer poised? Do controllers such as nF4 need a driver to utilise NCQ or is it a hardware thing?

 

[smids]

Very informative. Sticky

Thanks! . I want to get it as right as possible first, getting corrections etc first before asking Rilot or Werewolf. If you have any questions, please let me know and I'll include it if it helps others.

 

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Thanks to bigjonnyauk for giving me a new question and answer - unknowingly.

 

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[pimp mode]have a look in the sticky theres some hard drive tools at the end of the first post, have a go with HDTach for now see what that gives you. [/pimp mode]

Guys, if you feel uncomfortable with his pimping, let me know - I know the proper authorities. .

But yeah, unless you have a nForce4 board (where you can just check the drivers in Device Manager), the only way to know is something like HDTach. Interesting question though, and will be added to FAQ. Thanks Huddy!

 

[smids]

Any more comments/questions you think need to be included?

 

[smids]

Fair enough, I'll look at it again tomorrow and perhaps split the question up. Thanks for the input.

EDIT:

Basically it can be split into parts. No-one will benefit from the increased transfer rate of 300MB/s (aka 3.0Gbp/s) unless they have a RAID0 etc.

A single drive at 7200RPM can only produce about 55-60MB/s. Raptor 10K about 60-75MB/s - depends.

A 3.0gbp/s drive will work on all motherboards with SATA (1 or 2) but may require a jumper setting for SATA1 controllers (to force 150MB/s [aka 1.5gbp/s] transfer rate].

A 3.0gbp/s drive will work just fine on a 3.0gbp/s capable mobo leaving the owner with nothing to do (except Hitachi's which require the full rate to be switched on).

It does make sense to me, but it was aimed at exactly members like yourself, so I haven't done a good enough job. I will fix it to make it more clear.

 

[smids]

That makes sense. I was being silly, sorry .

I do have a question though. Would 4 disks be needed in raid 0 for 3gb/s? Or more? Or fewer? Where do you get 4 from?

Also a good link is this from hardcoreware.net. The benchmarks show your point very nicely.

Good work

Thanks for the link - I'll include it somehow.

About your question - my answer is that it was really a guestimate. I was thinking about a 4 x 74GB raptor RAID. Each individual raptor can hit about 70Mb/s so 280mb/s in RAID0. Then take inefficiencies into account and you have about 250MB/s average read. As you can see though, you need more than 2 drives to breach the 1.5gbp/s limit of SATA1. My 2 raptor 74GB drives in RAID0 have an average read of 128MB/s.

You can have any number, but the point is that no benefit it reaped over SATA1 from having such a controller/drive unless you use more than 2 disks in a RAID0.

 

[smids]

Quick question. I am planning a new build soon and was thinking along the lines of a raptor originally but then read some things and decided to go with 2 x 160gb SATA2 Hitachi Deskstars.

However from reading this sticky, would I be better off going for 4 x 80gb Deskstars instead?

Plus I also have an existing Maxtor 120gb SATA1 drive I planned on keeping for storing files like drivers, mp3's etc, would I still be able to have this?

Well, it really does depend. Are you planning on RAID0'ing 4 drives? I strongly advise against this because the chances of failure is up 4 fold but so long as you just need the speed and no important data then I don't see why not. Make sure you hve enough ports. Using a maxtor as a storage drive .

I do actually have 4 x 80GB Deskstars in a RAID0+1 - RAID0 array of 2 drives mirrored to another RAID0 array of 2 drives. Thus I have 160GB of extremely fast, very reliable data and no longer need to worry about drive failures on my windows install which can even be used to storage. This is what I suggest - RAID0 is fast enough on its own with 2 drives, let alone more, but this way you have reduncancy.

You would however at least be one of the few to take advantage of the 3.0gbp/s transfer rate of SATA-II (SATA controller permitting). Unless you need 320GB of RAID0, I would go with 160GB of RAID0+1 which makes it faster, cheaper and more reliable than a 150GB raptor.

 

[smids]

Thanks for that. I don't need 320gb of storage but the more the better if you know where i'm coming from. The main reason would be for speed

I am planning on using the DFI nF4 Ultra-D Mobo which does support the 3gb/s SATAII option.

SO just to clarify, putting it into my language with 4 x 80gb deskstars I could either run all 4 in raid 0 (320gb total) or run 2 in raid 0+1 and mirror with 2 in raid 0 (160gb total) with the 160gb mirrored option being faster and more secure?

Yes - but dont forget this will use all the ports up - you'll need a PCI sata card (very cheap) or an IDE drive as a storage drive .

I actually run 4x80GB Hitachi's in a RAID0+1 on that exact board as you may see from my sig. If you find the hitachi's loud at all, I believe there is also an acoustic management utility in the Hitachi Drive tools which allows you to run it up or down (with obvious performance impacts). Currently I get about 97MB/s sustained read, 400MB/s burst and 12.7ms access time for reference.

 

[smids]

One extra thing i've just thought of. How does the slower access time impact the performance?

Very, very little. There is only the tiniest overhead when using a RAID, whilst all drives settle on the correct bit of data. This is miniscule. Of course a raptor is faster but you wouldn't notice.

 

[smids]

Hmm, which version is the maxtor (DM9, 10, Maxline 2, maxline 3)? Now, one thing I'm not sure about is RAID'ing drives with different cache sizes. It should work, but I don't know how it will affect performance. Also, RAID'ing IDE drives apparently gives poor performance. I'm not sure why but I read this on the nV nForce forums. The Maxtor seems the way to go for space but again, recent reliability issues must be taken into account. Your choice is like that of a rock or a hard place. Also, what is the use of the drive?

PS - I'm subscribed to this thread and see all replies .

 

[smids]

its a DM10 i believe and the drives use is a main drive, used for strage and file transfere, on avg i shift 20 to 40gb a day around.

Hmm, those DM10's have had bad problems on nF4 boards and reliability is an issue. Go for it if a good price but keep regular backups .

 

[smids]

Yeah, you are right. You'll get all the speed (actually faster due to RAID1 killing writes). You can still RAID1 the storage drive though separately .

 

[smids]

I still don't see what the benefit is?

My new WD Caviar 16MB Cache HD is running in Sata 2 mode. And what is the difference between LBA anc CHS, which is better?

There isn't much unless you run a RAID type array where you can saturate the bandwidth. I think SATA-II is unfairly labelled as the 300MB/s bandwidth only though, when in actual fact the SATA-II standard brings a lot of features with it (though whether they are implement by manufacturers is another matter).

LBA and CHS - not great on those, but I know I cannot boot with CHS on my board. I leave it on Auto and it all works fine.