Do I need a new raid controller?

[rottweiler]

I'm building a new system and getting new hard drives and am wondering if I need a new controller. Currently I have 6 seagate 320GB sata drives on a 3Ware 9500S-8 controller. I have bought 3 1TB WD green drives to replace them. For one thing I don't think my card supports SATA-II. And if it does, can PCI even handle 3.0Gb/s?

I'm getting an Asus Maximus Formula and a Q6600 and am wondering what raid controller would work for me. When I bought the 3Ware I decided I wanted a top end controller. I don't think that's necessary any more. This is just a home PC which will act as the file server for my other home computers. Hopefully I'll build my HTPC sometime and use this as network storage. I am not worried about hardware processing since I will have a Quad core mostly going to waste anyway.

I spent about $500 on the 3Ware controller three and a half years ago. Hopefully I can get a decent 8 port SATA-II controller for half that, or even less, now.

Please recommend something for me that will fullfil my needs. Thanks.

 

[DanNeely]

PCIe is 2.5GB/sec/lane, so a 4x card would have the bandwidth to handle a 4 drive RAID5 or 3 drive RAID0 at SATA2 speeds for as long as it took to saturate the drive/controller caches. Once the caches are filled the sustained rate drops to around 700Mbit/sec or a bit less, so even on a 1x SATA1 card you'd only be loosing a burst speed not sustained.

 

[Grentz]

and you do know that not even SATAII drives can use the bandwidth?

SATAII drives are not any faster than SATAI cause they cannot even fill the SATAI bandwidth...

 

[rottweiler]

PCIe is 2.5GB/sec/lane, so a 4x card would have the bandwidth to handle a 4 drive RAID5 or 3 drive RAID0 at SATA2 speeds for as long as it took to saturate the drive/controller caches. Once the caches are filled the sustained rate drops to around 700Mbit/sec or a bit less, so even on a 1x SATA1 card you'd only be loosing a burst speed not sustained.

2.5GB/s or 2.5Gb/s? Since SATA-II is 3.0Gb/s 2.5GB/s would handle it just fine.

and you do know that not even SATAII drives can use the bandwidth?

SATAII drives are not any faster than SATAI cause they cannot even fill the SATAI bandwidth...

No, I didn't know. So, what's the point of SATA-II? Is it just a gimmick, until faster drives come along? Does that mean that I should just keep my current controller?

And I am planning on doing Raid 5, and expanding later when I need more.

 

[DanNeely]

2.5GB/s or 2.5Gb/s? Since SATA-II is 3.0Gb/s 2.5GB/s would handle it just fine.

They're both gigabits.

No, I didn't know. So, what's the point of SATA-II? Is it just a gimmick, until faster drives come along? Does that mean that I should just keep my current controller?

Burst speed. Up until you fill the 8/16MB drive cache you can write at the speed of the bus. If the HDs cache controller can correctly guess the data you want to access next you can read the first 8/16MB at the speed of the bus. The real world benefits are small, and probably don't justify buying a new controller. High Speed SSDs come much closer to maxing out the available bandwidth, but they're server components and priced far higher than the ones currently showing up in rugged/ultra portable laptops. When hybrid drives with fast flash start coming out it might become more important, but for the most part SATA, like every other bus maker is just pushing to make sure that upgraded bandwidth is widely available before it is needed.

 

[mavalpha]

SATAII supports better queueing (wow, I never get tired of looking at that word!), meaning they are generally better at prioritizing read/write requests. That generally means minimally better performance, but both your drive and controller have to support TCQ and/or NCQ (both have to support the same type). I believe TCQ is less frequently used, so more devices use NCQ now.