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Ugly
Fishy Cool Bird
join:2001-12-12
The Meadow
 ·Comcast
| reply to koitsu
Re: [SSD RAID-0] This will be so stupid fast! Anyone done this?
said by koitsu  :You should be looking at using standard SATA controllers that your OS has drivers for natively (e.g. Intel ICHx chipsets), and rely on the OS to do the striping. Remember: given the amazing response time of SSDs and the incredible power behind present-day desktop CPUs (Core2Duo and higher), using CPU-based I/O is trivial on desktops. Servers are a very different beast. Hum, is the Raid implementation on this Gigabyte mobo »www.newegg.com/Product/Product.a···13128358 from a standard SATA controller?
said by koitsu : I don't particularly like BIOS RAIDs because you're tied in to the vendors' metadata implementation; if one of your drives in the array dies, you'll very likely be visiting a data recovery shop to get your array back. (In fact, I've seen two recent posts on this forum of users having to do exactly that -- I warned them...  Do backups, folks!) How does one reliably avoid this? Will these chipsets do it right with a pair of SSD's?
Chipsets
North Bridge Intel P45
South Bridge Intel ICH10R
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Oh, I love the smell of fish. Guts, rotten, it's all good. | |
koitsu
Premium
join:2002-07-16
Mountain View, CA
2 edits | The GA-EP45-UD3P has two SATA controllers -- an Intel ICH10R, and a JMicron controller (which Gigabyte calls "GIGABYTE SATA2"). The GIGABYTE SATA2 controller is wired to the purple SATA ports (labelled "GSATA2_x"), while the Intel is wired to the orange ones (labelled "SATA2_x").
Here's a high-resolution image of the board; the controller you should avoid is at the very bottom of the board. I recommend you disable the GIGABYTE SATA2 controller in the BIOS and avoid the purple ports; instead use the ICH10R exclusively.
"Why do you hate JMicron?"
Three reasons: 1) shoddy drivers, 2) undocumented controllers (making it hard for open-source developers), and 3) responsible for the horrible performance seen in cheap MLCs (re: the JMicron SATA controller on SSD drives + Samsung memory). The company has existed too long to have these kind of recurring problems, so screw 'em.  I feel the same way about Realtek.
said by Ugly :How does one reliably avoid this? Will these chipsets do it right with a pair of SSD's? Chipsets North Bridge Intel P45 South Bridge Intel ICH10R The southbridge (ICH10R) is what drives SATA, not the northbridge (P45). See page 31 of the Intel ICH10 PDF for what devices/features the ICH10 southbridge is responsible for.
You can avoid use of vendor-centric metadata by NOT choosing "RAID" mode in the BIOS for your system. Instead, you can use your operating system's native RAID or disk interleaving support (in this case striping). Here's a list of present-day OSes and what's available, specifically RAID-0:
FreeBSD: ZFS, gstripe, gvinum, ccd
Linux: Btrfs, md
OS X: Disk Utility
Solaris: ZFS, Solaris Volume Manager
Windows: Striped volumes (requires use of "dynamic disks", see Microsoft's site or Google)
I have no idea what said features in Windows and OS X perform like, or how to administrate them.
You can use BIOS-level RAID if you want (with Intel ICHxx controllers it's quite reliable on the Windows platform), but you need to remember that once you set your BIOS to RAID mode, the *entire controller* acts in RAID mode. You can't tell it "I want RAID-0 on ports 0 and 1, and standard SATA/non-RAID on ports 2-5". However, you can used a "mixed mode" environment; say you have 4 disks on the ICH10R, and you want 2 to be standalone (non-RAID) and 2 to be RAID-0. You can do that -- you just define the RAID-0 stripe in the ICH10R BIOS (not the PC BIOS!) for 2 of the 4 disks.
Also worth noting is that when the ICHxx controllers are in RAID mode, you cannot have ATAPI (CD/DVD) drives connected to them; they won't function. This works fine if the controller is operating in Enhanced, Compatibility (PATA emulation), or AHCI mode.
Some of the above OSes also have limitations/problem if your OS is installed on a RAID-0'd volume and you're using the OS-level RAID. I have a tendency to keep my OS disks as standalone (no RAID), and for RAID volumes use a separate controller or use OS-level RAID. E.g. a 3-disk system would have 1 disk for the OS, and 2 disks for a RAID-0 stripe or RAID-1 mirror.
And do not let anyone tell you that AHCI == RAID; that's false. I use AHCI on all of my ICH7R boards and *do not* use BIOS-level RAID. AHCI is just an interface command specification that's standardised so OSes can speak AHCI to the controller rather than having to speak the classic ATA protocol(s). It's a good protocol when implemented correctly (Intel has it down pat, AMD/ATI has theirs down pretty good with some quirks, and I have no idea about nVidia, VIA, JMicron, or SiliconImage).
EDIT: Added a note about JBOD when Intel controllers are in RAID mode, and a note about ATAPI drives.
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Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer. | |
Ugly
Fishy Cool Bird
join:2001-12-12
The Meadow | Wow! -- Simply one of, if not the, most kind, helpful, and informative posts I've ever read at DSLR.com. Evah!
How does that kudos thingy work?
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Oh, I love the smell of fish. Guts, rotten, it's all good. | |
koitsu
Premium
join:2002-07-16
Mountain View, CA
| reply to Ugly
Well I got my X25-M this week, and thought I'd blog about it.
»koitsu.wordpress.com/2009/06/17/···dows-xp/
At this point I'm going to return it. I don't think present-day software, nor Windows XP, is really "ready" for SSDs yet. I'll probably be looking into getting a WD3000HLFS instead, as that drive should run at a lower temperature than my present hard drive and provide faster I/O. (My first 10krpm drive...)
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Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer. | |
Ugly
Fishy Cool Bird
join:2001-12-12
The Meadow
·Comcast
| That's a great read; worth the click.said by koitsu :At this point I'm going to return it. I don't think present-day software, nor Windows XP, is really "ready" for SSDs yet. I'll probably be looking into getting a WD3000HLFS instead, as that drive should run at a lower temperature than my present hard drive and provide faster I/O. (My first 10krpm drive...) Hum, certainly its fair to say that Windows 7 will do somewhat better.
Indeed, let's just dig a bit deeper.
• Windows 7 has native Raid support, right?
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Oh, I love the smell of fish. Guts, rotten, it's all good. | |
Cabal
Premium
join:2007-01-21
Boston, MA
| reply to koitsu
said by koitsu :Well I got my X25-M this week, and thought I'd blog about it. » koitsu.wordpress.com/2009/06/17/···dows-xp/At this point I'm going to return it. I don't think present-day software, nor Windows XP, is really "ready" for SSDs yet. I'll probably be looking into getting a WD3000HLFS instead, as that drive should run at a lower temperature than my present hard drive and provide faster I/O. (My first 10krpm drive...) Did you 4K-align the partition(s) prior to installing XP? I didn't see it in my skimming of the post, and many of your symptoms mirror those problems described in the oft-linked OCZ forum post about proper SSD partitioning.
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koitsu
Premium
join:2002-07-16
Mountain View, CA
| Cabal is referring to these two threads:
»www.ocztechnologyforum.com/forum···?t=50376
»www.ocztechnologyforum.com/forum···?t=48309
No, I hadn't done any of that. In fact, I think that just adds further evidence to my frustration; somehow I'm magically supposed to have an existing machine running Windows where I can create the partition/filesystem along a 4KB boundary point. This proves that you literally cannot "drop in" an SSD to be a HD replacement, at least with XP.
Not only was I unaware of these implications, and although I am *quite* familiar what it is diskpart.exe does (technically), such a requirement is... well, I'm disappointed. The SSD is still going back, because chances are I will absolutely forget this as well as all the other "one-offs" to get the performance benefits, the next time I format the machine (which I do with Windows every 4-5 months). In fact, this whole "dance" reminds me of the rigmarole I had to go through with VIA chipsets and Windows 2000.
I told Ugly I'd be most interested to hear how Windows 7 performs on his 2xSSD RAID-0 stripe once he gets all of that squared away. If W7 does all of this out-of-the-box, then awesome (I already run W7 on my laptop at work, but it's HDD-based).
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer. | |
sdgthy
@optonline.net
 from:
Ugly
| said by koitsu :This proves that you literally cannot "drop in" an SSD to be a HD replacement, at least with XP. Same thing applies for a RAID array, it's nothing new. I do think I've seen something about Vista making this easier. | |
aurgathor
join:2002-12-01
Lynnwood, WA
| reply to koitsu
said by koitsu :This proves that you literally cannot "drop in" an SSD to be a HD replacement, at least with XP. That actually depends on the type of the SSD. DRAM based, or simpler flash based SSD should have less issue than flash based SSDs with sophisticated firmware.
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And the winner is: | |
Cabal
Premium
join:2007-01-21
Boston, MA
| reply to koitsu
said by koitsu :This proves that you literally cannot "drop in" an SSD to be a HD replacement, at least with XP. That's correct. I'm not sure why you're surprised, though, it was released 8 years ago. Vista and Windows 7 correctly align partition boundaries on install.
At this time, I don't believe any Linux or BSD distributions do so correctly, either, but there are plenty of write-ups about it.
»thunk.org/tytso/blog/2009/02/20/···ck-size/
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Interested in open source engine management for your Subaru? | |
Ugly
Fishy Cool Bird
join:2001-12-12
The Meadow
·Comcast
| said by Cabal :
Vista and Windows 7 correctly align partition boundaries on install.
So here's the current plan, involving BOTH XP and Win7. (not wasting time w/ Vista)
1. The mobo gets up and running with an ordinary spinniing platter HD and boot from Win XPpro.
2. Next, a SSD or pair of SSD's are added.
3. Boot into Win7 install disc and employ tools of Win7 installer to create SSD partition for OS and Raid-0 (no bios-type Raid!). Bird says, "No need for Raid-driver floppy and F6. This is Win7" -- Right? 4. Complete Win7 installation.
Result = dual boot: XP and Win7.
Is this good?
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Oh, I love the smell of fish. Guts, rotten, it's all good. | |
Martinus
Premium
join:2001-08-06
EU | reply to Ugly
Great thread.
So, the consensus is that Windows 7 correctly aligns partition boundaries on install and you don't need to do anything extra "by hand"?
I'm planning on getting a couple of SSDs for my next rig when W7 comes out. | |
Fishead1
Premium
join:2001-05-08
Bronx, NY
| Am I right that all your gaining with a RAID 0 is loading time like booting up and in games when they need to populate a new area say in a game or reloading a saved game?
I went thru the whole RAID thing back in 2005 and thought I was going to have games run faster.
I can see the value in other RAID 1 ,RAID 5,RAID 10 ,etc for back up of important stuff (redundancy). | |
Ugly
Fishy Cool Bird
join:2001-12-12
The Meadow
·Comcast
| reply to koitsu
said by koitsu :And do not let anyone tell you that AHCI == RAID; that's false. I use AHCI on all of my ICH7R boards and *do not* use BIOS-level RAID. AHCI is just an interface command specification that's standardised so OSes can speak AHCI to the controller rather than having to speak the classic ATA protocol(s). It's a good protocol when implemented correctly ( Intel has it down pat, AMD/ATI has theirs down pretty good with some quirks, and I have no idea about nVidia, VIA, JMicron, or SiliconImage). I got this from a friend:
»en.wikipedia.org/wiki/TRIM_(SSD_command)
said by Wikipedia :
TRIM has already been implemented in Windows 7 release candidate, but until solid state drives are updated with firmware that can understand the command, it will simply be ignored. It looks like Win7 is gonna be good. -- Perhaps even better than the Hardware?
• How does one know if the X25-E Intel SLC drives can handle the TRIM command?
--
Oh, I love the smell of fish. Guts, rotten, it's all good. | |
koitsu
Premium
join:2002-07-16
Mountain View, CA
| said by Ugly :It looks like Win7 is gonna be good. -- Perhaps even better than the Hardware? • How does one know if the X25-E Intel SLC drives can handle the TRIM command? I'd Email Intel Support and ask. (If I was keeping my X25-M I'd probably consider doing this myself.) Be sure to request that the question be given to an actual engineer for confirmation.
There's an answer on the Intel forums, but I would take it with a grain of salt.
I've also yet to find any actual specification details of said TRIM command; I can't find anything on t13.org, nor is there anything in Intel's official AHCI 1.3 spec. The only way to be sure to is to get in contact with an actual engineer.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer. | |
sdgthy
@optonline.net
from:
Ugly
| reply to Ugly
Nice find, I was wondering what exactly TRIM was...
I think if you check the 2CPU thread it's mentioned that a later firmware version for the Intel X25-E added TRIM support.
It's starting look like all the good SSD's will only be SATA.  I want a PATA version for my laptop... | |
Ugly
Fishy Cool Bird
join:2001-12-12
The Meadow
·Comcast
| said by sdgthy :
Nice find, I was wondering what exactly TRIM was...
I think if you check the 2CPU thread it's mentioned that a later firmware version for the Intel X25-E added TRIM support.
OK, so that only leaves the mobo chipset as being unclear on whether it does or does NOT support the TRIM command.
• Any ideas on the mobo supporting TRIM, please?
--
Oh, I love the smell of fish. Guts, rotten, it's all good. | |
koitsu
Premium
join:2002-07-16
Mountain View, CA
4 edits | I don't think the motherboard/chipset (specifically southbridge) would be responsible for TRIM. Well, sort of. I'd better explain.
The ICH10 acts as a controller, but does not act as an ATA command filter device. You can submit invalid ATA commands to a disk attached to the SATA bus, and you'll get back an error from the drive if the command isn't supported -- this happens all the time with OSes like Solaris and Linux which do SATA-to-SCSI emulation (drive appears in the OS as a SCSI drive, uses SCSI utilities and kernel features, but when sending actual commands to the drive, go through a software (kernel) "translation" layer which maps SCSI commands to ATA).
Meaning: with ATA, it's up to 1) the OS to know what commands to send to the drive, and 2) the drive to understand said commands.
But with regards to AHCI, that might be a different story altogether. AHCI does appear to define a list of permitted commands per specification revision, and (usually) a controller can support a newer AHCI revision assuming its microcode can be updated. Usually this is done via a PC BIOS upgrade.
But as I mentioned, I can't find any confirmation of TRIM existing in the AHCI 1.3 specification, nor on t13.org (who's responsible for the ATA command set, e.g. ATA-8 and so on).
EDIT: Ah ha, I found it! The TRIM command isn't part of any official standard at this point -- it's defined in a working draft over at t13:
»www.t13.org/Documents/UploadedDo···CS-2.pdf
Relevant sections:
- Section 7.10.3.2
- Section 7.18.7.1
- Section 7.18.7.30 (defines "indeterminate behaviour", e.g. if capabilities don't match)
Based on Section 7.18.7.1, issuing command 0xEC (IDENTIFY DEVICE) to the device attached to the ATA bus, and examining bit #0 of word 169, we can determine whether or not the device supports TRIM (1 == available, 0 == not available).
"So how do I do this?" Well, not easily. I think Linux offers a way to submit custom ATA commands to the device and get back all the raw data returned. FreeBSD offers this capability but only through SCSI (using "camcontrol cmd"). It's definitely possible to modify FreeBSD's ata(4) driver and atacontrol(8) command to support something similar. On Windows, it's probably possible too, but I have no idea how to interface with an ATA drive at such a low level on Windows.
But remember, this is a working draft, which does not guarantee any existing devices (on market or in development) support it. Some can, but they don't have to; it's not an official published standard yet, hence "working draft". For all we know, the word offset at 169 could be moved to some other offset in the next draft. *shrug* This is much like vendors releasing 802.11n WiFi devices on the market when the specification isn't even out of draft yet.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer. | |
Ugly
Fishy Cool Bird
join:2001-12-12
The Meadow
·Comcast
| said by koitsu :Meaning: with ATA, it's up to 1) the OS (We assume here - Win7 RC) to know what commands to send to the drive, and 2) the drive to understand said commands. But with regards to AHCI, that might be a different story altogether. AHCI does appear to define a list of permitted commands per specification revision, and (usually) a controller can support a newer AHCI revision assuming its microcode can be updated. Usually this is done via a PC BIOS upgrade.But as I mentioned, I can't find any confirmation of TRIM existing in the AHCI 1.3 specification, nor on t13.org (who's responsible for the ATA command set, e.g. ATA-8 and so on). EDIT: Ah ha, I found it! The TRIM command isn't part of any official standard at this point -- it's defined in a working draft over at t13:» www.t13.org/Documents/UploadedDo···CS-2.pdf"So how do I do this?" Well, not easily. ... On Windows, it's probably possible too, but I have no idea how to interface with an ATA drive at such a low level on Windows. But remember, this is a working draft, which does not guarantee any existing devices (on market or in development) support it. Some can, but they don't have to; it's not an official published standard yet, hence "working draft". For all we know, the word offset at 169 could be moved to some other offset in the next draft. *shrug* This is much like vendors releasing 802.11n WiFi devices on the market when the specification isn't even out of draft yet. Hum, I think the point here is that one should not even think about finding TRIM as a standard mobo feature for a while.
And I'm certainly NOT going to try hacking this myself!
Whenever it DOES become available, (assuming by then one's mobo is not too old for the manufacturer to even bother) the addition of the TRIM functionality will be done via offering a new BIOS update file to download from the mobo manufacturer's website. Of course, newly manufactured mobos will ship with TRIM already installed in the shipping BIOS.
Frankly, I am happy to wait for a coherent standard and do not need a manufacturer to try a rushed rogue implementation by itself.
• Have I got this right koitsu ?
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Oh, I love the smell of fish. Guts, rotten, it's all good. | |
koitsu
Premium
join:2002-07-16
Mountain View, CA
3 edits | Not exactly. I've re-written the below quite a few times trying to explain it, because it's not something you can just write tersely and have it all make sense.
SATA devices such as hard drives and SSDs all speak a form of ATA protocol. This is often referred to by revision, e.g. ATA-4, ATA-6, ATA-7, ATA-8, etc... You can see what ATA revision applies to what kind of devices over at Wikipedia. The ATA protocol revision defines what commands (see below) a device should ("can") support.
SATA ATAPI devices (CD/DVD drives) speak the ATAPI protocol, but we're not going to talk about those.
Certain drive features are only available via AHCI. Commonly, these are: hot-swap functionality (which can also be achieved through a custom OS driver) and NCQ. Again, Wikipedia explains some of what AHCI provides.
You might be wondering: "why do I need AHCI to use NCQ?" This is a little off-topic, but I'll describe it anyway. NCQ is actually something that has to be supported on the SATA controller as well as the disk itself. Instead of the OS submitting one request at a time to the controller ("I want to read this LBA from device X" "Please wait. Okay here's your data" "Thanks, now I want to write this LBA to device X" "Please wait..."), the OS can actually submit multiple requests (called commands) to the SATA controller. The controller and/or disk can then re-order those commands based on where on the disk (physically) you're trying to access, so that things are accessed in a more rotational-disk-friendly order -- otherwise you have to wait until the platters make another revolution before being able to get your data, which wastes time. Wikipedia documents the feature quite well. NCQ plays a huge role in server environments, where you might have a server submitting tons of read/write requests all at once, and you want all those read/write requests optimised in proper order based on the above.
And now TRIM (see the link for a pretty awesome walk-through from t13 about what it's solving):
I haven't read anything in the specifications that indicates TRIM is a controller-driven or controller-centric feature. Meaning, I have no indication that a SATA controller needs "support for TRIM". On the other hand, all of the specifications I've read so far indicate that the 1) device (disk) and 2) host OS have to support TRIM. There's an article over at ibm.com with regards to Linux supporting TRIM, and all I see there is mention of it being required on the device and in the OS -- no mention of SATA controller involvement.
This could change. TRIM could become something that requires AHCI, leaving the OS (mostly, but not entirely) out of the picture. In this situation, an AHCI specification update would be required, and that could be provided via a SATA controller BIOS upgrade or a PC BIOS upgrade (for on-board SATA).
There simply isn't enough evidence at this point. This sounds harsh (especially given that I'm posting on a forum), but I can't trust what I read over on the OCZ forums -- those are just residential users blabbing about what's better and lots of mumbo jumbo. I'd really have to talk to an *actual engineer* familiar with both the in-draft ATA specification as well as SSDs to determine where the focus point is.
Bottom line: the world doesn't know enough about TRIM at this point to make it a deciding factor when purchasing an SSD, a SATA controller / motherboard, or an OS. It's a really great feature, so I can understand everyone's enthusiasm, but it's not standardised yet!
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer. | |
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