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New HDDs for Raid 0

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  • Hard Drives
  • NAS / RAID
  • Western Digital
  • Storage
Last response: in Storage
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July 7, 2010 7:44:01 PM

I'm buying two new harddrives for Raid 0. I have three questions:

1) Which is best for Raid, WD Caviar Black or Seagate 7200.12?

2) Does HDD cache size make a difference in Raid 0? (32mb vs 64mb)

3) Does the size of the hdd affect Raid 0 performance? (2x2tb vs 2x1tb)


Just fyi, I will be installing Windows 7 Ultimate 64bit upon setting up the Raid.



Also, someone linked this to me but I dont know how accurate/true the info is

http://www.supremelaw.org/systems/io.tests/platter.tran...

Thanks for the help!

More about : hdds raid

July 9, 2010 12:40:52 AM

Bumping to amend my questions here....

I am now considering a 60gb SSD for my OS drive. I still plan on grabbing two 1tb drives to perform Raid 0, but I am now considering these two drives:

$200 - Western Digital Caviar Black 7200 1tb 64mb cache

or

$150 - Samsung Spinpoint F3 7200 1tb 32mb cache

Any opinion on the performance of these drives?
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November 9, 2010 8:43:12 PM

I don't know about the Samsung because I am a Western Digital guy. You can use a Caviar Blacks in a RAID 0 array. You cannot use them in any other RAID configuration/array. The reason being the TLER is no longer enabled in WD drive with the exception of their RE3 and RE4 drives, which are made specifically for RAID. They cost a little more, but you won't have drives falling out all the time. Your best education on the TLER and other RAID info is on the WD web site. Do yourself a favor and go there, look up your 2TB Caviar Black and it will tell you exactly what you need to know. I have basically laid it out for you, but read what WD says, because if you use their drives for any purpose other than what WD designed them for, they will not stand behind warranty. Good luck!


stonedzen said:
Bumping to amend my questions here....

I am now considering a 60gb SSD for my OS drive. I still plan on grabbing two 1tb drives to perform Raid 0, but I am now considering these two drives:

$200 - Western Digital Caviar Black 7200 1tb 64mb cache

or

$150 - Samsung Spinpoint F3 7200 1tb 32mb cache

Any opinion on the performance of these drives?

m
0
l
Related resources
a c 127 G Storage
November 10, 2010 2:08:03 AM

Your disks will still drop from the array when using Windows onboard RAID or hardware RAID combined with non-TLER capable disks, even in RAID0 or JBOD or single-disk arrays.

The reason for this is the behavior of the RAID implementation, which is very strict and treats any disk that spends longer than 10 seconds on recovery as failed, and detaches it from the array. Metadata on the remaining disk members is then updated, so this change is permanent and remembered across reboots. Very annoying!

This is what causes the many split/broken/failed arrays. All works fine, until one of your disks experiences BER or Bit-Error-Rate, exceeding the ECC correcting capability of the drive. In that case, the drive may spend more than 10 seconds on recovery, the RAID engine kicks the disk out and you have a degraded or failed array, depending on your configuration. Since RAID0 can withstand no disk failures, disk would cripple your array.

This very common with Windows onboard RAID, and is becoming an increasingly likely scenario since high-capacity disks have still the same Bit-Error-Rate, making the likelihood of BER occurring greater as capacities grow bigger. 2TB disks with 512-byte sectors in particular are vulnerable. Using 4K sector disks which have bigger ECC pools is a logical step to reduce BER.

If you truly want good protection for your data, the best-in-class protection against corruption, BER and first-class software-RAID, then you really must look at ZFS, it is a very innovative new filesystem design that incorporates a RAID engine and filesystem in one package, making things possible that theoretically are impossible if these two concepts are implemented completely separate, such as is the case with conventional RAID, software or hardware.

For Windows users, the best they can do is invest in a good backup solution, and use something that automates incremental backups. HDDs cannot be trusted, many RAIDs alike. That's no problem depending on how important the data is and whether or not you have a recent complete backup.
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November 10, 2010 3:31:06 PM

I am going to use 3 x WD6401AALS Caviar Black HDD's in RAID 0. Here is what Western Digital says about this HDD in RAID 0, 1, followed by the link to WD and the 640GB HDD.

NOTE: These drives are recommended for "Consumer RAID Environments", which is what I am using them for. They are NOT recommended for "Business Critical RAID Environments". This is true of all Caviar Blacks.

"Ideal For"

"Power computing applications such as multimedia, video and photo editing, and maxed out gaming computers."
"Desktop / Consumer RAID Environments - WD Caviar Black Hard Drives are tested and recommended for use in consumer-type RAID applications (Raid-0 / RAID-1).*"

"*Business Critical RAID Environments – WD Caviar Black Hard Drives are not recommended for and are not warranted for use in RAID environments utilizing Enterprise HBAs and/or expanders and in multi-bay chassis, as they are not designed for, nor tested in, these specific types of RAID applications. For all Business Critical RAID applications, please consider WD's Enterprise Hard Drives that are specifically designed with RAID-specific, time-limited error recovery (TLER), are tested extensively in 24x7 RAID applications, and include features like enhanced RAFF technology and thermal extended burn-in testing."

http://www.wdc.com/en/products/products.asp?driveid=551

Here is WD's info on the 2TB Caviar Black, with link.
WD recommendations for the 2TB, Model: WD2001FASS, are identical to all of the Caviar Black HDD's; see above.

http://www.wdc.com/en/products/products.asp?driveid=733




sub mesa said:
Your disks will still drop from the array when using Windows onboard RAID or hardware RAID combined with non-TLER capable disks, even in RAID0 or JBOD or single-disk arrays.

The reason for this is the behavior of the RAID implementation, which is very strict and treats any disk that spends longer than 10 seconds on recovery as failed, and detaches it from the array. Metadata on the remaining disk members is then updated, so this change is permanent and remembered across reboots. Very annoying!

This is what causes the many split/broken/failed arrays. All works fine, until one of your disks experiences BER or Bit-Error-Rate, exceeding the ECC correcting capability of the drive. In that case, the drive may spend more than 10 seconds on recovery, the RAID engine kicks the disk out and you have a degraded or failed array, depending on your configuration. Since RAID0 can withstand no disk failures, disk would cripple your array.

This very common with Windows onboard RAID, and is becoming an increasingly likely scenario since high-capacity disks have still the same Bit-Error-Rate, making the likelihood of BER occurring greater as capacities grow bigger. 2TB disks with 512-byte sectors in particular are vulnerable. Using 4K sector disks which have bigger ECC pools is a logical step to reduce BER.

If you truly want good protection for your data, the best-in-class protection against corruption, BER and first-class software-RAID, then you really must look at ZFS, it is a very innovative new filesystem design that incorporates a RAID engine and filesystem in one package, making things possible that theoretically are impossible if these two concepts are implemented completely separate, such as is the case with conventional RAID, software or hardware.

For Windows users, the best they can do is invest in a good backup solution, and use something that automates incremental backups. HDDs cannot be trusted, many RAIDs alike. That's no problem depending on how important the data is and whether or not you have a recent complete backup.

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a c 127 G Storage
November 10, 2010 5:39:51 PM

What do you expect them to tell you? The truth?!

"We at Western Digital are clever businessmen. We already give the customer less than he thinks he's buying in terms of capacity, and now we're letting our customers pay extra for a solution for a bug that we created. Instead of improving the design of our harddrives, we continue to sell bugged drives and offer the bugfix for an added amount of money." Sounds like really great strategic thinking!

Except, that TLER is no silver bullet, and even if you pay for it your data is still at risk. TLER actually can increase the likelihood of weak sectors turning into uncorrectable sectors, as TLER prevents the disk to spend more than 7 seconds in recovery time, never giving that weak sector a decent chance of being recovered. The result is that TLER remains unsafe in situations where you lost your redundancy, such as on RAID0 and JBOD, but also RAID5 or RAID6 that are degraded and no longer provide any redundancy protection.

Assume you have a RAID5 with 8 disks. Now one disk fails, you buy a new disk and you start rebuilding. Only during rebuild one of the remaining disks experiences BER and causes am uncorrectable sector. This likely would stop the rebuild process and may cause you to loose access to your array altogether. Your data is still there, and can still be recovered with some minor single-sector dataloss. But the moral of this story is that RAID5 is not so safe after all!

The only solution to this problem, is using advanced filesystems like ZFS, or utilizing solid backup solutions that you can trust. Don't consider any traditional RAID and RAID5 in particular to be very safe. Best if you consider it to have the same reliability as a single drive without RAID.
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November 10, 2010 11:42:56 PM

If what you say is reality, then WD is in essence lying to everyone. Correct? I have heard others say the same thing you did in your last post. I even called WD twice just to see what they would say. And I was given two different stories. One said Caviar Blacks would work in RAID 0, 1, 0 + 1, and 1 + 0 or 10. Bottom line is, if they say the drives I have work on the site for that drive, then they are liable.

I could just run the drives I have anyway, and if they fail, just keeping sending them in for replacement. I would do that just to rub their collective noses in it, I can be that way sometimes, ornery, it's the Veteran in me, PTSD, or what ever. However, not being one to rely on just one means of backing up my stuff, I figured why run RAID 1. I was thinking RAID 0 just because I have the drives and the extra speed sounded fun. I came across the TLER issues while I was researching RAID because I have never used it, and knew nothing about it a couple of months ago. Now, I would rather use a good software program to back up what ever I wanted backed up. I have read of others, (in another forum) that have been running Caviar Blacks in RAID 0, and 1, with no problems. Some are using the newer Caviar Blacks with TLER disabled, and some are running the earlier versions with some enabled and some not. All are saying they have had no problems to date. The time their drives have been in RAID 0 or 1 varies from 2 years to recent months. One thing everyone seems to agree on, is Caviar Blacks will not work in anything higher than RAID 0 and or 1. Most are also backing up their OS, files, photo's or what ever is important to them with external and internal drives. HDD's are so inexpensive why not use internal drives in Docking Stations, or External Drive Enclosures, with multiple bays. Most also allow the drives to be hot swaped.

I know nothing about ZFS, never heard of it until I read it here. Is it expensive? Can you explain it a little more, in layman's term? Thanks. I am definitely open to using something other than RAID.

otemsg=1828896,6,414794]What do you expect them to tell you? The truth?!

"We at Western Digital are clever businessmen. We already give the customer less than he thinks he's buying in terms of capacity, and now we're letting our customers pay extra for a solution for a bug that we created. Instead of improving the design of our harddrives, we continue to sell bugged drives and offer the bugfix for an added amount of money." Sounds like really great strategic thinking!

Except, that TLER is no silver bullet, and even if you pay for it your data is still at risk. TLER actually can increase the likelihood of weak sectors turning into uncorrectable sectors, as TLER prevents the disk to spend more than 7 seconds in recovery time, never giving that weak sector a decent chance of being recovered. The result is that TLER remains unsafe in situations where you lost your redundancy, such as on RAID0 and JBOD, but also RAID5 or RAID6 that are degraded and no longer provide any redundancy protection.

Assume you have a RAID5 with 8 disks. Now one disk fails, you buy a new disk and you start rebuilding. Only during rebuild one of the remaining disks experiences BER and causes am uncorrectable sector. This likely would stop the rebuild process and may cause you to loose access to your array altogether. Your data is still there, and can still be recovered with some minor single-sector dataloss. But the moral of this story is that RAID5 is not so safe after all!

The only solution to this problem, is using advanced filesystems like ZFS, or utilizing solid backup solutions that you can trust. Don't consider any traditional RAID and RAID5 in particular to be very safe. Best if you consider it to have the same reliability as a single drive without RAID.[/quotemsg]
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a b G Storage
November 11, 2010 8:00:09 AM

I have been using RAID 0 for a long time - both decent and brutal. For WD Black Caviar consider 640Gb not 1Tb or 2Tb (I have read a russian site for this regarding spindle problems) but I have use a 1Tb on RAID 0 as my storage (no problem). The only pain on the aXX on RAID 0 is temperature and power failure in your area, make sure to invest on hard disk cooling too.
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a c 127 G Storage
November 11, 2010 4:15:46 PM

Larry141 said:
If what you say is reality, then WD is in essence lying to everyone. Correct?

Intentional confusion, obfuscation, withholding of vital information... yes you could consider that lying. But to be honest all large companies are low on their ethics to see their profits grow. If you were a car broker and you had that hard-to-sell stupid car which nobody wanted for good reasons, and someone unknowning shows up with interest for the car; then what will you do? Will you be honest and say don't buy that one nobody buys it there's something better at my competitor next door? :D 

Ethics and business are hard to combine. You can assume that you're being ripped off one way or another with most products, there's always some catch to it. IT products in particular use alot of psychological marketing to let the consumer think in such a way that it would prefer more expensive products, for bigger margins.

Quote:
I even called WD twice just to see what they would say. And I was given two different stories. One said Caviar Blacks would work in RAID 0, 1, 0 + 1, and 1 + 0 or 10.

Well that is crap; not like the HDDs know in what kind of RAID they are being used. For all it knows it's a single disk with NTFS on it; HDDs are block-level storage devices they have no knowledge about what the HDD is being used for.

The question is, which RAID engine is going to handle your disk. If that's a software RAID engine under Linux/BSD which are written decently and won't detach drives performing recovery, then you're fine. If you attach this disk to a hardware RAID or windows driver/onboard RAID engine, then things will be different and the strict engine will detach disks that spend too long on recovery time. This varies from cheap onboard RAID (Intel, AMD, nVidia, VIA, Silicon Image) to expensive Hardware RAID cards like Areca ARC-1220. It is possible some hardware RAID is more tolerant towards desktop drives and let them perform recovery; but i've not seen any proof any product that actually falls into this category.

So for onboard RAID + hardware RAID you would need TLER disks, in whatever configuration you are running, to prevent them being dropped out of the RAID. Do note, that TLER increases BER or Bit-Error-Rate, which makes the likelihood of a bad/unreadable sector occurring much higher, since your disk will only be allowed 7 seconds to repair the damage; or FORFEIT its attempts. If you're running RAID0 then basically you're screwed since without TLER your disks will drop and with TLER bad sectors would cause corruption very quickly. Doh!

So if you want advanced RAID without having to buy TLER disks, the only solution is a non-Windows software RAID environment, like Linux or FreeBSD or OpenSolaris. ZFS is a great answer against BER and corruption, and is the most reliable method to store your data on multiple HDDs. If you want to stick to Windows-platform, then do not trust RAID too much and instead spend your money on a REAL backup solution; so another x drives that syncs every night with your main array, for example. And truly important data on a USB Stick as well; so it's stored three times.

Quote:
I know nothing about ZFS, never heard of it until I read it here. Is it expensive? Can you explain it a little more, in layman's term? Thanks. I am definitely open to using something other than RAID.

ZFS is essentially an advanced new filesystem that integrated a volume manager or RAID engine. Nothing like it exists, and i would say it's a revolution in storage. But i'm a ZFS zealot; ZFS is not for everyone.

It only runs well on advanced UNIX operating systems, which are not really meant for desktop users but for system operators. However, some distributions exist that try to lower the threshold for people using ZFS. These projects include FreeNAS, NexentaCore and my own ZFSguru distribution. FreeNAS and ZFSguru might be the easiest to try. You can try either of them in a Virtualbox VM session, which works much like VMware except its opensource/free. So you could create a VM with 4 virtual disks and boot the livecd from FreeNAS or ZFSguru and access the web-interface, then create a ZFS pool and share it using Samba, then your Windows computer can access it and create a drive letter for it like X:\. To do that just enter "\\10.0.0.20" in address bar of an explorer window, without the " " characters. Change the IP to the server IP. This is calling 'mapping a network drive', you map that network address to a drive letter so you can easily access it.

FreeNAS can be found on www.freenas.org
ZFSguru doesn't have a real website yet; you can use the main thread on HardOCP forums for download link and more information:
http://hardforum.com/showthread.php?t=1521803

If you want to try my dist, then you would want to download ZFSguru-0.1.7-preview2.iso and then update to preview2c version via the web-update.

Perhaps i'm telling too much; it shouldn't be too difficult to try this out and do basic things like creating a software pool (RAID5 or whatever) and sharing it across the network.

ZFS needs a decent amount of RAM; a real ZFS server should have no less than 4GiB RAM and best is 8GiB+, for performance reasons. But you can save money on not needing TLER disks, normal consumer disks do fine. You also don't need a hardware RAID controller with BBU (battery backup), so that saves money too. You can mix onboard ports and ports on add-on controller; but it should not be a RAID controller! Good 8-port HBA (=normal controller) would be Intel SASUC8i, SuperMicro USAS-L8i is another consideration; i use two of them. They sell for around $100-160, are PCI-express x8 and work great with ZFS.

If you want to explore more about ZFS, the thread i linked to another threads in that forum might provide alot of information, and i can assist you as well with questions you may have. But you do have to consider that the downside of going the ZFS route is that you would need to spend time on getting to know this and make this work for you. You will get reliable storage and potentially lower hardware costs in return, though.
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November 14, 2010 3:51:48 PM

dEAne, thanks for your comments.

I am going to use 640GB Caviar Blacks, because that is what I purchased before finding out about the TLER issue....had I known about the TLER deal before buying 3 x 640GB's I would have bought RE3 HDD's. I can't do both now so I will try those drives and see what happens. I am going to use them in RAID 0 for more performance. If I decide to give RAID 1 a try I will use two RE3 HDD's in an external enclosure. Even then I will also use external HDD's to save my OS and important files. I am not using the computer for business, just a powerful all around home computer. So all of my important docs, files, movies, etc., will be kept on swapable HDD's. I just want my system simple and reliable.

What HDD's are you using, manufacturer, model, etc? Do they have TLER that you can enable for disable?

Power failures are not a big issue where I live, but I will use a backup power supply, at least enough to shut down my system. I have a generator that I can start within a couple of minutes in the case of a power failure, but it does not start automatically. I have to start it manually, but I don't even have to go outside to start it. I can run it for about 150 hours before needing more fuel, running at full power. In the winter if I just use a minimum of lights and the heater in the winter, it will run longer on it's fuel supply.




dEAne said:
I have been using RAID 0 for a long time - both decent and brutal. For WD Black Caviar consider 640Gb not 1Tb or 2Tb (I have read a russian site for this regarding spindle problems) but I have use a 1Tb on RAID 0 as my storage (no problem). The only pain on the aXX on RAID 0 is temperature and power failure in your area, make sure to invest on hard disk cooling too.

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November 14, 2010 4:03:59 PM

sub mesa, thanks for your reply's and comments.

All very interesting information. I am going to just keep it simple as I just wrote to dEAne. All of the knowledge you have shared with me is beyond my abilities at this time, and quite frankly, I am to busy with other things right now to start learning about all you have mentioned. I do believe you are on to something really good that might, or will work better than RAID. From what I have learned overt the past couple of months tells me that something better needs to done, because in my opinion RAID is, or is becoming, archaic.



sub mesa said:
Intentional confusion, obfuscation, withholding of vital information... yes you could consider that lying. But to be honest all large companies are low on their ethics to see their profits grow. If you were a car broker and you had that hard-to-sell stupid car which nobody wanted for good reasons, and someone unknowning shows up with interest for the car; then what will you do? Will you be honest and say don't buy that one nobody buys it there's something better at my competitor next door? :D 

Ethics and business are hard to combine. You can assume that you're being ripped off one way or another with most products, there's always some catch to it. IT products in particular use alot of psychological marketing to let the consumer think in such a way that it would prefer more expensive products, for bigger margins.

Quote:
I even called WD twice just to see what they would say. And I was given two different stories. One said Caviar Blacks would work in RAID 0, 1, 0 + 1, and 1 + 0 or 10.

Well that is crap; not like the HDDs know in what kind of RAID they are being used. For all it knows it's a single disk with NTFS on it; HDDs are block-level storage devices they have no knowledge about what the HDD is being used for.

The question is, which RAID engine is going to handle your disk. If that's a software RAID engine under Linux/BSD which are written decently and won't detach drives performing recovery, then you're fine. If you attach this disk to a hardware RAID or windows driver/onboard RAID engine, then things will be different and the strict engine will detach disks that spend too long on recovery time. This varies from cheap onboard RAID (Intel, AMD, nVidia, VIA, Silicon Image) to expensive Hardware RAID cards like Areca ARC-1220. It is possible some hardware RAID is more tolerant towards desktop drives and let them perform recovery; but i've not seen any proof any product that actually falls into this category.

So for onboard RAID + hardware RAID you would need TLER disks, in whatever configuration you are running, to prevent them being dropped out of the RAID. Do note, that TLER increases BER or Bit-Error-Rate, which makes the likelihood of a bad/unreadable sector occurring much higher, since your disk will only be allowed 7 seconds to repair the damage; or FORFEIT its attempts. If you're running RAID0 then basically you're screwed since without TLER your disks will drop and with TLER bad sectors would cause corruption very quickly. Doh!

So if you want advanced RAID without having to buy TLER disks, the only solution is a non-Windows software RAID environment, like Linux or FreeBSD or OpenSolaris. ZFS is a great answer against BER and corruption, and is the most reliable method to store your data on multiple HDDs. If you want to stick to Windows-platform, then do not trust RAID too much and instead spend your money on a REAL backup solution; so another x drives that syncs every night with your main array, for example. And truly important data on a USB Stick as well; so it's stored three times.

Quote:
I know nothing about ZFS, never heard of it until I read it here. Is it expensive? Can you explain it a little more, in layman's term? Thanks. I am definitely open to using something other than RAID.

ZFS is essentially an advanced new filesystem that integrated a volume manager or RAID engine. Nothing like it exists, and i would say it's a revolution in storage. But i'm a ZFS zealot; ZFS is not for everyone.

It only runs well on advanced UNIX operating systems, which are not really meant for desktop users but for system operators. However, some distributions exist that try to lower the threshold for people using ZFS. These projects include FreeNAS, NexentaCore and my own ZFSguru distribution. FreeNAS and ZFSguru might be the easiest to try. You can try either of them in a Virtualbox VM session, which works much like VMware except its opensource/free. So you could create a VM with 4 virtual disks and boot the livecd from FreeNAS or ZFSguru and access the web-interface, then create a ZFS pool and share it using Samba, then your Windows computer can access it and create a drive letter for it like X:\. To do that just enter "\\10.0.0.20" in address bar of an explorer window, without the " " characters. Change the IP to the server IP. This is calling 'mapping a network drive', you map that network address to a drive letter so you can easily access it.

FreeNAS can be found on www.freenas.org
ZFSguru doesn't have a real website yet; you can use the main thread on HardOCP forums for download link and more information:
http://hardforum.com/showthread.php?t=1521803

If you want to try my dist, then you would want to download ZFSguru-0.1.7-preview2.iso and then update to preview2c version via the web-update.

Perhaps i'm telling too much; it shouldn't be too difficult to try this out and do basic things like creating a software pool (RAID5 or whatever) and sharing it across the network.

ZFS needs a decent amount of RAM; a real ZFS server should have no less than 4GiB RAM and best is 8GiB+, for performance reasons. But you can save money on not needing TLER disks, normal consumer disks do fine. You also don't need a hardware RAID controller with BBU (battery backup), so that saves money too. You can mix onboard ports and ports on add-on controller; but it should not be a RAID controller! Good 8-port HBA (=normal controller) would be Intel SASUC8i, SuperMicro USAS-L8i is another consideration; i use two of them. They sell for around $100-160, are PCI-express x8 and work great with ZFS.

If you want to explore more about ZFS, the thread i linked to another threads in that forum might provide alot of information, and i can assist you as well with questions you may have. But you do have to consider that the downside of going the ZFS route is that you would need to spend time on getting to know this and make this work for you. You will get reliable storage and potentially lower hardware costs in return, though.

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February 28, 2012 4:33:10 PM

don't know about raid but the f3 1tb drive is very good i have one
it's fast so in raid 0 it will kill.
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!