SATA 2 drive on a SATA 1 controller?

[Svenghetti]

I understand I can safely install a 250GB SATA drive alongside my existing 40GB PATA drive. But can I safely connect a SATA 2 drive to my Dell's SATA 1 controller? (I would like to get SATA 2 pending an upgrade to a new computer, and I have read that SATA 2 is backwards compatible.)

Cheers.

Dell Precision 360
Win XP Pro

 

[rvnguy]

You have read correctly, they are backward compatible. Some drive mfg's also have their SATA II's jumpered to to only connect as SATA I. One would have to reset jumper to use at SATA II interface speeds. As I recall, they did this as there were some problems with some controllers.

rvnguy
"I know everything..I just can't remember it all

 

[Svenghetti]

Thanks Rvnguy. The drive I am thinking of getting is the Hitachi - Deskstar T7K250 SATA 2. A review elsewhere states: "The [250GB, SATA 1] 7K250 uses three platters, which is around 80GB per platter, but the [250GB, SATA 2] T7K250 reviewed here stands out because it is a twin-platter model, so each platter stores 125GB of data. The amount of data on each platter is significant because the tighter you pack it in, the less distance the read/write head has to move, and that increases hard drive performance."

Is there general agreement on this? I can see the argument but doesn't packing the data in more tightly also mean the drive might prove less reliable?

 

[rvnguy]

I am not a hitachi fan but this looks to be a good drive with a 3yr warranty.

there are 4 heads, so each side of a platter is 62.5GB

rvnguy
"I know everything..I just can't remember it all

 

[cdogg]

Yes, higher density and less platters typically results in faster seek times overall. However, there's not going to be a "huge" difference. I'm not a big fan of Hitachi either, but when it comes to hard drives, they're decent in that area.


As for your original question, keep in mind that the spec SATA II can be misleading. Some manufacturers use it to show that their drives have extra features like NCQ (Native Command Queuing). Others use it to show that the drive is meant for the 3Gbps interface. Therefore, you can't assume that SATA II means the faster interface known as SATA 2.5.

This article touches on that:

http://www.anandtech.com/storage/showdoc.aspx?i=2450

With that said, does it matter if you have a 3Gbps drive running on the old SATA 1.5Gbps interface? Not necessarily. The drive is backwards compatible like you read and will run at full speed on the older SATA bus. The only time the faster 3Gbps interface matters, is when running multiple SATA drives in an intensive RAID configuration that needs the additional bandwidth. For a single drive, this does not matter AT ALL.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[cdogg]

Sorry, one correction...

SATA 2.5 does not mean that the drive is compatible with 3Gbps. 2.5 was meant to lump all the new features of SATA into one. It's possible to see SATA 2.5 drives that only operate at the 1.5Gbps level.

For your Dell system, you need to find out if some of the extra features, such as NCQ, is supported. Otherwise you're wasting extra money buying a hard drive that has them.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[alildevil]

Well hes not wasting the extra money/features of the drive that he can't use at this time to its fullest, he/she is planning to use the drive in a future build. Makes sense to have the drive that he can carry over, and not have to get a new one to replace it.

 

[Svenghetti]

Thanks everyone. My understanding now is that I can safely use a SATA II drive on a SATA I controller. I've also discovered the Hitachi drive doesn't have jumpers - it comes configured for SATA I and can be changed for SATA II using a small DOS program. Regarding the price: the SATA II drive is actually cheaper than the equivalent SATA I drive because, presumably, (and as I mentioned in a previous post) it only has 2 platters and the other one has 3. Which begs the question: why would anyone with SATA buy the SATA I version?!

 

[cdogg]

As little as 6 months ago, 2nd generation SATA drives were usually more expensive than 1st gen. Now that most drives you see these days are starting to shift to 2nd gen, prices are falling. In some cases, like you've pointed out, the 2nd gen drive is even cheaper usually due to inventory issues.

Also realize that the number of platters doesn't usually have anything to do with the SATA interface. There are drive models out there for plain old IDE, for example, that have similar specs. As mentioned before, higher density is usually better, but if you were to use both the 80GB platter drive and the 125GB platter drive, I doubt you would "feel" the difference. Both drives would run fine on the SATA 150MB/s interface, and likely even on the 100MB/s (ATA/100) IDE interface.

SATA has little to do with the overall performance of a single hard drive, since most drive transfer rates average below 50MB/s. The extra features like NCQ are the ones that can make SATA drives outperform their IDE counterparts. Also, some RAID configurations will work faster on an SATA controller versus IDE.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884