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SSD RAID support

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November 2, 2009 2:34:49 AM

Is there an automatic RAID support for Serial ATA Solid State Disk without any seperate RAID controller card? Could you suggest a mark and model for 32GB Serial ATA Solid State Disk?

More about : ssd raid support

a c 127 G Storage
November 2, 2009 3:55:53 AM

Please describe what you want to do, its not clear to me.

If you want more performance, invest in a better SSD. The best SSD now is Intel X25-M G2, which comes in 80GB and 160GB. Modern SSDs use "RAID0" internally, so if that's what you mean these SSDs already have that. If you want to use multiple SSDs to achieve even higher performance, you can do that just fine with onboard RAID chips, for example Intel ICHxR MatrixRAID.

SSD Performance depends 99% on the controller chip that's being used; and the Intel controller provides the highest performance at this moment.
November 2, 2009 6:41:04 AM

sub mesa said:
Please describe what you want to do, its not clear to me.

If you want more performance, invest in a better SSD. The best SSD now is Intel X25-M G2, which comes in 80GB and 160GB. Modern SSDs use "RAID0" internally, so if that's what you mean these SSDs already have that. If you want to use multiple SSDs to achieve even higher performance, you can do that just fine with onboard RAID chips, for example Intel ICHxR MatrixRAID.

SSD Performance depends 99% on the controller chip that's being used; and the Intel controller provides the highest performance at this moment.


Thank you for your worthful information. I could get the information I wanted!
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November 2, 2009 9:44:06 AM

sub mesa said:
Please describe what you want to do, its not clear to me.

If you want more performance, invest in a better SSD. The best SSD now is Intel X25-M G2, which comes in 80GB and 160GB. Modern SSDs use "RAID0" internally, so if that's what you mean these SSDs already have that. If you want to use multiple SSDs to achieve even higher performance, you can do that just fine with onboard RAID chips, for example Intel ICHxR MatrixRAID.

SSD Performance depends 99% on the controller chip that's being used; and the Intel controller provides the highest performance at this moment.


I've just rejoined THF and the question I have is similar to what I think 'Negar ' was asking: and that is, do you have to have a specific add-on RAID Controller hardware as opposed to using on board RAID chips...and you have replied "no, on-board RAID chips are OK'. So far so good. The thing that interests me tho' is that in very many ratings of SSDs, on retailer sites like say Newegg, nearly everyone talks about their RAID Controller and talk about it in a manner which suggests [at least that's how I interpret what they are saying] that it is crucial to have the right one in order to use SSDs. It occurs to me that if you are willing to spend the money on SSDs, particularly more than one, so as to use in RAID, you would want to have a decent MOBO anyway and as far as I can see most halfway decent MOBOs these days have RAID chips onboard.
You've answered the original question so what I've got to say may just be 'add-on' but I can't help wondering what these retailer ratings repliers are on about.
a c 127 G Storage
November 2, 2009 10:07:26 AM

I don't exactly know what question you're trying to ask. If i read your story correctly, your question is "is it really true that onboard RAID controllers are OK and is there any significant difference?".

First i would like to comment about using SSD's in RAID. Solid State Drives are very different from HDDs. HDDs can't be made much faster; each generation is only marginally faster than the previous one. This is a limitation of physics; the only real advancement is increasing the data density, increasing the rpm and cache size, and some firmware tweaks. That's it.
For SSD's however, the controller is key to performance. Cheap SSDs have bad controllers that can have good read performance but fail at providing good write performance. Good controllers like Intel is using in their popular SSDs, are using multiple channels and intelligent logic to provide extremely high performance. Not only when doing simple sequential I/O - large files - but also more complicated I/O which is much more important in real life and very much overlooked. Since I/O is too complex for more ordinary people to understand, all you hear in marketing and even on forums like this one is MB/s - not IOps which is a much better way of expressing performance.

To make a story short: you don't need RAID to enhance the performance of SSDs. Modern SSDs use RAID0 or striping/interleaving internally already; the Intel controller has 8 separate channels to do I/O with. Future controllers can use even more. So even with the same flash memory chips, performance can be enhanced by many many times that of current SSDs. So not a modest 20% increase but like 200.000% performance increase is theoretically possible.

That said, if you are looking for SSDs now and want to enhance its performance, you can use RAID0 without any problems. So your question: which RAID engine to use? Since SSDs provide very low latency; any hardware RAID controller in PCI-X or PCI-express interface will slow down the SSDs as they have their own processing time. On the other hand they can speed up throughput and IOps but there's also a slowdown effect; it depends on the application which is faster.

Onboard RAID controllers should have the lowest latency (=fastest); as its directly connected with the chipset (the southbridge). The popular Intel chipsets (ICHxR) also allow you to enable 'write caching' (which is technically wrong since its not a cache but a buffer). This is dangerous because it can corrupt your filesystem in case of a crash or power failure, but can provide very high performance in certain cases by using your RAM memory as "buffer" for writing - enhancing performance in many realistic cases, much like real Hardware controllers do with their onboard dedicated memory.

So its possible an Intel RAID0 array provides higher performance than very expensive hardware RAID controllers, when using SSDs. Much of the optimizations the hardware RAID controllers use (such as I/O reordering and I/O combining) is useful on HDDs only - not SSDs!

So there are several reasons onboard RAID solutions are 'on par' or even superior to real hardware RAID solutions.

Hope this answers your question, if not ask away. :) 
November 2, 2009 10:37:59 AM

sub mesa said:
I don't exactly know what question you're trying to ask. If i read your story correctly, your question is "is it really true that onboard RAID controllers are OK and is there any significant difference?".

First i would like to comment about using SSD's in RAID. Solid State Drives are very different from HDDs. HDDs can't be made much faster; each generation is only marginally faster than the previous one. This is a limitation of physics; the only real advancement is increasing the data density, increasing the rpm and cache size, and some firmware tweaks. That's it.
For SSD's however, the controller is key to performance. Cheap SSDs have bad controllers that can have good read performance but fail at providing good write performance. Good controllers like Intel is using in their popular SSDs, are using multiple channels and intelligent logic to provide extremely high performance. Not only when doing simple sequential I/O - large files - but also more complicated I/O which is much more important in real life and very much overlooked. Since I/O is too complex for more ordinary people to understand, all you hear in marketing and even on forums like this one is MB/s - not IOps which is a much better way of expressing performance.

To make a story short: you don't need RAID to enhance the performance of SSDs. Modern SSDs use RAID0 or striping/interleaving internally already; the Intel controller has 8 separate channels to do I/O with. Future controllers can use even more. So even with the same flash memory chips, performance can be enhanced by many many times that of current SSDs. So not a modest 20% increase but like 200.000% performance increase is theoretically possible.

That said, if you are looking for SSDs now and want to enhance its performance, you can use RAID0 without any problems. So your question: which RAID engine to use? Since SSDs provide very low latency; any hardware RAID controller in PCI-X or PCI-express interface will slow down the SSDs as they have their own processing time. On the other hand they can speed up throughput and IOps but there's also a slowdown effect; it depends on the application which is faster.

Onboard RAID controllers should have the lowest latency (=fastest); as its directly connected with the chipset (the southbridge). The popular Intel chipsets (ICHxR) also allow you to enable 'write caching' (which is technically wrong since its not a cache but a buffer). This is dangerous because it can corrupt your filesystem in case of a crash or power failure, but can provide very high performance in certain cases by using your RAM memory as "buffer" for writing - enhancing performance in many realistic cases, much like real Hardware controllers do with their onboard dedicated memory.

So its possible an Intel RAID0 array provides higher performance than very expensive hardware RAID controllers, when using SSDs. Much of the optimizations the hardware RAID controllers use (such as I/O reordering and I/O combining) is useful on HDDs only - not SSDs!

So there are several reasons onboard RAID solutions are 'on par' or even superior to real hardware RAID solutions.

Hope this answers your question, if not ask away. :) 


I guess I wasn't really asking a question, but I'm glad I wrote something, because you have just provided the most thorough and easy to understand and concise input to the whole question of RAID/SSD/ HDD, that I have come across anywhere. Well done and thanks Mate.
a c 127 G Storage
November 2, 2009 10:41:17 AM

You're welcome. :) 
!