Intel SSDs in Raid0 - Long term use

This question is more practical than my previous ones on SSDs,

My budget is ~$450, and I've been told in many ways that Intel's SSDs are superior to those of any other manufacturer if you include price as well as performance in the mix. Since I'm still a noob, I'll accept this.

I'll need about 160Gb of space, so this leaves me with two options:

1x Intel X25-M 160Gb
2x Intel X25-M 80Gb in Raid0.

I know how fast SSDs can be when you pull them out of the box, but my question here is which of these two options will yield the highest speed after months of usage being, say, 70-80% full?

I am undecided because I have seen excellent performance scaling with SSDs in raid, but they don't support TRIM while in raid, so performance loss is inevitable... the issue is really if heavy usage will drag the performance of the array below the level of the 160Gb drive.

You might be inclined to reply with "it depends on how you use the drive", to which I will say the drive will be used for Windows 7, apps & games and will be used every day. Once the drive has started to fill up, writing to the drive will be done rarely, but will inevitably happen as windows writes every time you boot up. Some performance degradation may be inevitable so I am willing to format, secure erase & essentually "start over", every 6 months or so, so long as performance is restored.

Some side questions:

- Should I store windows on another drive? Does frequent windows loading degrade the performance of an SSD even with TRIM?
- Are there other options (other manufacturers: OCZ, patriot, etc.) wich I have overlooked, and have comparable speed and price?
- Will new SSD controllers come out in the near future that allow TRIM while the SSD is in an array?

Finally,

- A lot of these questions are vague, and might not have clear answers, so, what would you do in my place?

As always, I'll take any/all help I can get.

Thanks in advance (esp. submessa, he's been a great help)

I'd stick with Intel. And as a boot drive. Why else buy a SSD to put Windows on a HDD?

To fully utilize TRIM, I'd get the 160GB, if that is what you truly need. It'll keeping the drive at "max performance." All that you want to watch for is getting close to full capacity, which you already commented on. You could always partion the drive to 80-85% of capacity if you are scared of gettiing close to full. The other 15-20% would be left unused & unformatted for "drive optimization."

What I suggest is using your current HDD for data/media/storage, and just use the SSD for OS and Program Files. This should minimize writes to the SSD, after the initial install. And, all your data/media will be safe if the SSD or OS crashes. See my set up below.

Yes, Windows will "write every time you boot up" but not that large of amount of data. IMHO: To fully get the speed out of a SSD, I left everything alone. Yes, things like pagefile and internet cache do "corrupt" the drive, but wouldn't you still want fast access to these files too? I did once post a comment on slow downs on boot ups, but it seems to have "recovered." Programs still launch like lightning! I LOVE IT!

We can only hope Intel (or Microsoft, or whomever) will come out with TRIM support for SSD in a RAID array (I do, my SSDs are in a RAID 0)!

sub mesa AND sminlal are great at SSD topics!

^+1

Given the obvious premium for the best SSDs e.g. Sandforce SF-1222,
I still think it's wiser to wait until the kinks are better resolved
and, in particular, until SATA/6G SSDs become the norm,
and affordable -- particularly for someone with your budget.

You must factor into your buying decisions the FACT
that SSD manufacturers are prone to report BEST CASE
performance, and they are hesitant to reveal the
degradation that all MLC SSDs will experience over time.

There are no lifetime warranties on any Nand Flash SSDs
that I've seen or read about.

And, you are required to ask your excellent questions because
simple answers are just not that easy to find!

You might want to consider 2 x "RAID Edition" ("RE" ) HDDs
from Western Digital:

http://www.wdc.com/en/products/pro [...] anguage=en

For practical reasons, a 5-year warranty comes in very handy
for our office: we always compute price per warranty year,
and the 5-year warranties always come out ahead on this metric.

We have 2 x WD7502ABYS configured in RAID 0 on one of our
workstation system partitions, and the remainder is a large data partition:
we're very pleased with the performance:

http://www.newegg.com/Product/Prod [...] WD7502ABYS

Two of the smaller WD2502ABYS should provide comparable performance,
on average:

http://www.newegg.com/Product/Prod [...] WD2502ABYS

Another interesting option is Hitachi's 2.5" 147GB 10,000 rpm SAS/6G HDD
with 64MB cache (a smart move on their part, imho):

http://www.newegg.com/Product/Prod [...] -_-Product

Bear in mind that SAS requires a SAS-compatible controller
either on the motherboard, or an expansion card, and this
SAS HDD also requires a 6G interface.

It's now very easy to adapt a 2.5" form factor to a 3.5" drive bay.

We also strongly disagree with those who argue that
RAID 0 is more prone to fail: we've experienced just
the opposite. And, if one of the 2 drives fails,
all data are lost and the failed HDD must be replaced,
which is exactly the same situation if the same data set
is on a single spindle ("same difference"

You can always demote such a RAID 0 with rotating platters
to a dedicated data partition, e.g. archiving/backups, AFTER the
SSD market settles down and meets the current 6G standard.

At that point in time, the availability of SATA/6G SSDs
should put downward pressure on the prices of SATA/3G SSDs,
at least.

Also, chipsets should be more widely available with
native TRIM support for RAID arrays e.g. see AMD's 890FX.
That is another, good reason to wait for SSDs to mature
some more.

I hope this helps (yes, I know you SSD lovers may climb all over me:
fine! I encourage freedom of speech at all times.)

MRFS

SSDs only degrade write performance from being full. Read performance doesn't take any hits. This is because SSDs need to do a delete cycle and write cycle to replace information from used sections.

Most people use SSDs for boot drives which doesn't get much write action. However if you are shuffling information around with an SSD, then you would suffer more without the TRIM command.

Only true for simple first-gen SSDs that do not do write remapping.

This is the traditional way of how SSDs dealt with random writes: always do a slow read-erase-program cycle with high write amplification. Logical LBA = Physical LBA.

Newer SSDs like Intel do write remapping; they actually write small writes requests to a different location to where the Operating System thinks it is being stored. This way, it can avoid the slow and write-heavy read-erase-program cycle and writes to a free erase block without having to erase anything. This speeds up these random writes considerably, but it does require the SSD to keep track of the difference between how Windows thinks the data is stored, and how it is actually stored on the NAND flash; this is stored in the Mapping Table located in the HPA or Host Protected Area of the SSD.

Now the real clue: as this table gets fuller due to random writes, and fragmentation due all relocations begins lowering the available free erase blocks, you would also degrade your read performance as well. This can be seen already after a clean install of Windows; the parts where random writes or modifications have happened would show degraded read performance. This slight degradation is not possible to avoid on modern SSDs. It's a trade-off and generally makes sense, as SSDs are pretty fast in reading also. Here's how it would look like:



There is a lot more to it than the above, for example i haven't named that due to fragmentation fewer flash channels can be used in parallel; lowering performance. But this approaches my own understanding, and i'm reluctant to test and 'battle wear' my own precious Intel SSDs; which i really enjoy having. Plus i enjoy bragging about my 1234MB/s random read performance sometimes.

In this thread on another forum i discussed SSD performance degradation in more detail:
http://forums.anandtech.com/showthread.php?t=2076773

I got some benchmarks! And after much ado, screenshots!

SSD = 2 x Intel X25-V 40GB in RAID 0
HDD = 2 x Seagate 7200.11 500GB in RAID 0
HDD-NR = 1 x Seagate 7200.12 1TB (no RAID!)

Test 1: Benchmark READ rate (can’t do writes test!)

SSD: Avg =246.3MB/s!!!




HDD: Avg = 151.0MB/s!




HDD-NR: Avg = 119.2MB/s




And results can vary. Ran it again, and look at the rise!!!

SSD: Avg = 305.4MB/s! Max = 437.0MB/s!

Ok, this is is. I don't what to fill up this forum with my tests! I already got a warning. I'll be a good boy!

Test 3: Random Access. Again SSD bombs everything else!

SSD = 2 x Intel X25-V 40GB in RAID 0:



HDD = 2 x Seagate 7200.11 500GB in RAID 0:



HDD-NR = Seagate 7200.12 1TB




My backup drive (non-RAID) beats my data/media drives (RAID 0)! Might have something to do with platter size.

No special disk utilities! No "measures." Like I said before, I DID NOT do any of the "tips" for SSD use (i.e. move pagefile, turn off PreFetch, etc.).

My drive does take a "hit" in the first 8GB where my OS is.

As also stated before, the only thing I did, with help from sub mesa, is I partioned the drive as only 80%, in 3 partitions:

1). System Reserved - 100MB - Part of Windows 7 install (no drive letter)
2). Windows - 64GB - Drive C: 21.4GB used, 38.5GB Free Space
3). The remainder, 16GB +/-, as unallocated, unformated, unused (for disk self optimization)(no drive letter)

Here is what my system looks like in Disk Magagement:



BTW: My stripe size is 128KB (recommended by RAID setup).

P.S. After a second look, I guess I "moved" my pagefile to my D: drive. I forgot. But I have 6GB of memory, so it's probably never used, just allocated as 6148MB in Windows managed size.

I question the use of RAID with SSD's for any reason. Redundant Array of Independent(Inexpensive) Disks was developed to overcome limitations of spinning disks with magnetic coatings. SSD's have none of these things. I plan to wait for Redundant Array of Independent Solid State Devices (RAISSD (raised)) or whatever the marketing guys name it.

sub: got links to Crystal or AS SSD?

I tried Crystal but must have had the wrong one. Looked nothing like what I've seen.