SATA III - why no better rating than SATA II ?

[Carol Haynes]

Just finished setting up my new system which comprises of:

Antec 300 case (2 large case fans which are pretty quiet)
Gigabyte 890GPA-UD3H motherboard
AMD Phenom II X6 1090T CPU
4 x 4Gb Crucial PC3-10600 RAM
2 x 1 Tb WD1002FAEX SATA III drives
2 x Pioneer DVD+-R DL writers
650W Corsair PSU
Sapphire Radeon HD6570 1Gb graphics card (to replace onboard graphics as I want to run 3 Samsung B2430H monitors)
Windows 7 Pro 64-bit
Microsoft Comfort Desktop 5000 (wireless keyboard and mouse)

Set up went well and everything worked first time.

I have now moved my old Creasive Soundblaster Audigy 2 ZS Platinum PCI card into the box and found the rather shoddy drivers on Creative's website and am thinking of going back to the onboard sound with my 7.1 speakers.

Also added my old Hauppauge TV card - which seems to work much better now and also works well through Windows Media Center.

Having done all this I looked at the system rating by Microsoft and it pegs at 5.9 because the drives are the lowest value. (Graphics rate at 7.0 and CPU and memory at 7.5).

I just set up a barebones system for a customer and installed a WD SATA II drive on a SATA II interface and that also pegs at 5.9.

The question is why do SATA II and SATA III drives peg at the same value? How can I get more speed out of the SATA III drives without resorting to striped arrays?

I have enabled AHCI mode in the BIOS so it isn't stuck in IDE Mode.

Enabling AHCI Mode in Windows 7

I had the devil of a job to find out how to stop the system BSODing as a result - FWIW here is the simple solution:

Set the following registry value:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci]
"Start"=dword:00000000

For some reason this is set to 3 at normal setup (even if you supply an AHCI driver during setup) which means AHCI is disabled. Setting it to 0 allows the system to install the drivers on the next boot. The process is as follows:

1) Set registry value
2) Reboot into BIOS and enable AHCI mode
3) Reboot into windows - allow the drivers to install
4) Reboot again.

If you miss booting into the BIOS it doesn't actually matter as the drives in WIndows simply stay in IDE mode - which begs the question why was it disabled in the first place?

The only other minor disappointment I have is that the stock AMD CPU cooler isn't exactly silent. It isn't bad but it is louder than I want - anyone know of a good AM3 coompatible silent CPU cooler that will keep a 6 core CPU nice and cool. (I don't want to splash out for water cooling!).

 

[f0dder]

How fast do your drives go?

SATA-1 can theoretically handle 150MB/s, SATA-2 300MB/s, and SATA-3 600MB/s. You need a high-end SSD to even max out a SATA-2 interface without striping.

[4wd]

^ What he said +1

As for coolers, Noctua.  Here's a StaticIce search.

Noctua NH-U9B-SE2 - 90mm dual fans, friend has one on a AMD Phenom II 965BE, very quiet.
Noctua NH-U12P-SE2 - 120mm version.
Noctua NH-C12P-SE14 - If you want to go parallel to the CPU.

I use a Cooler Master Hyper TX3, (StaticIce),quieter than the stock but cycles up and down a bit - it would probably be better if it included a second fan but I was on a budget, AU$27 vs AU$80-95 for the Noctua.

[Carol Haynes]

hanks for the comments - helpful.

Still don't really understand why SATA III drives on a SATA III interface don't see an improvement in system rating ???

[Ath]

Still don't really understand why SATA III drives on a SATA III interface don't see an improvement in system rating ???

-Carol Haynes (February 20, 2011, 05:37 AM)

That system rating actually measures the data transfer speed. As your SATA II interface already offers enough throughput to deliver the full potential of your disk, SATA III isn't needed, nor does it improve, the transferspeed to & from the disk.
You need a faster disk (or one with a higher burst-transfer, achievable by a big on-disk cache, but the system-rating probably has counter-measures to avoid falling into that trap) to require the need (and see any improvement) of a SATA III interface.

[f0dder]

Also, while SATA-2 added NCQ, it doesn't seem like SATA-3 adds much that would be relevant for speed, apart from of course the increased bandwidth.

[Carol Haynes]

I think this is getting confusing (at least for me):

Two different systems:

1) SATA II interface / SATA II drive - Windows rating 5.9 (in IDE mode)

2) SATA III interface / SATA III drive (64Mb cache) - Windows rating 5.9 (in AHCI mode)

Surely I should see SOME improvement otherwise what is the point of paying for SATA III drives?

[f0dder]

Surely I should see SOME improvement otherwise what is the point of paying for SATA III drives?

-Carol Haynes (February 20, 2011, 07:30 AM)

None - labeling a harddrive as SATA-3 is purely a marketing ploy, since mechanical disks don't even come close to saturating sata-2. Heck, how many drives reach the 150MB/s limit of sata-1?

Iirc, AHCI is required to enable NCQ, and that was added with SATA-2. But that's probably not going to impact the windows performance rating, afaik that mostly tests sequential transfer rate, and NCQ helps with scattered read/write requests.

[Carol Haynes]

Bummer - I wish I had just gone for SATA II drives now 

[zridling]

How fast are the platters spinning? If it's a storage-designed drive, it may be spinning at 5400 RPM. Many are these days.

[Carol Haynes]

7200 rpm

[4wd]

The fastest HDDs available, 15000 RPM Enterprise class, only get transfer rates near 200MB/s but you will need to use four (4) SATA III ports to get that since they're SAS interface.

And I don't think you want to pay for those

[f0dder]

The fastest HDDs available, 15000 RPM Enterprise class, only get transfer rates near 200MB/s but you will need to use four (4) SATA III ports to get that since they're SAS interface.

-4wd (February 20, 2011, 05:32 PM)

Huh? O_o

So you need to multiplex four sata ports to get a SAS connection? How come? One sata-2 port should easily be able to handle those 200MB/s.

[4wd]

TBH, I have no idea, I'm not even sure that if you use a SATA->SAS adapter that the SAS drive won't degrade itself to match the specs of the interface it's using.

It is a SCSI drive and as such has less protocol overheads than SATA - that will give an throughput increase if it was on a SAS interface all other considerations being equal between SAS/SATA.

But I guess if you put it on a SATA interface then it has to cope with the increased overheads of the ATA command set, it's performance would probably drop to the equivalent native SATA drive.

Maybe that's why you need 4 SATA ports multiplexed together, to overcome the performance loss of the protocol by increasing bandwidth ?

So you need to multiplex four sata ports to get a SAS connection?

-f0dder (February 20, 2011, 05:42 PM)

Oops! Just to clarify, a SAS drive will happily connect to one SATA port, the interface connector allows for it.  I just don't think you'll get near it's native SAS throughput because of the protocol considerations.

[Carol Haynes]

OK - so how are manufacturers getting away with this con? In the UK we have the "Trades Description Act" which is specifically designed to stop manufacturers conning consumers in this way - and it has been used recently to good effect with misleading claims about false internet speed claims from ISPs. I'm amazed the hard disk manufacturers haven't been challenged!

[4wd]

It's not really a con, after all the drive will transfer at 6Gb/s from it's internal buffer to the controller.  But after you've emptied the buffer then it has to get it from the mechanical section and that's where the bottleneck happens, (120ms later ).

The only spec that's relevant in this case is Sustained Throughput, (or similar), and doesn't it strike you as interesting that WD and Seagate no longer seem to put theirs on the website, (not even for Enterprise).

Hitachi provide Media transfer rate in Mb/s, (Media being the physical platter), and Samsung provide Media to Buffer in Mb/s, (figures seem a little optimistic to me), and then you have to take into account protocol overheads for the SATA bus as the figures given are raw drive internal transfer rates.

I'd guess that at the moment the only reason SATA III drives are more expensive than SATA II is because the manufacturers are trying to recoup their SATA III drive chipset development costs.

[f0dder]

4wd: you'd need an insanely fast disk in order for SAS vs. SATA-2/3 mattering anything with regards to throughput, and I doubt there's any mechanical disk right now where this matters. And as for ATA vs SCSI, I dunno if it's as much "protocol overhead" as it's about SCSI doing some things smarter, like (iirc) direct device->device transfers without involving the host controller.

Where SAS (and, for that matter, SATA-3) probably matters a lot more is when multiplexing one port to multiple drives, or connecting some RAID storage device that shows up a single SAS or SATA-3 device?

[4wd]

I dunno if it's as much "protocol overhead" as it's about SCSI doing some things smarter, like (iirc) direct device->device transfers without involving the host controller.

-f0dder (February 21, 2011, 02:26 AM)

Yes sorry, protocol was probably the wrong word but the only one that came to mind.  SCSI does do things a fair bit smarter such as Disconnect/Reconnect, (though in these point-to-point connections I'm not sure how useful it is), etc.

BTW, apparently new Sandforce controllers to be released later this year will push up SSD bandwidth to 500MB/s...time to start putting away those pennies