Is this the only hard drive you should buy?

[sophisticles]

I regularly replace my hard drives with fresh ones in order to avoid any unexpected crashes that result in complete data loss and I have been looking for the best product. I recently became aware of Western Digital's "Purple" line of drives:

http://www.microcenter.com/product/430612/Purple_Surveillance_Storage_4TB_Intellipower...WD40PURX_-_OEM

Does anyone have any experience with these? Here's what WD claims:

WD Purple Surveillance Storage is built for 24/7, always-on, high-definition surveillance security systems that use up to eight hard drives and up to 32 cameras.

Seems to me that these drives would be perfect for a video workstation, or any other PC for that matter. I read somewhere that these drives are rated for 180tb worth of writes per year, which means they should be really durable.

Does anyone know if these can be used in a desktop? They use a SATA interface, so I'm assuming that they should work with a home pc.

[drjtech]

A couple quotes from the WD forum:

http://www.wdc.com/en/products/products.aspx?id=1210&utm_source=WD%20Red%20redirect&ut...mpaign=product

"These drives are designed for "it's more important to complete the read or write in the specified time frame than that the data written or read be correct" usage. Pretty much the opposite of what you want in a NAS that stores important documents, business data, treasured photos/videos, or anything except short-lived (days, weeks) streamed data."

WARNING: Purple is for live video recording ONLY !!!
Athough the Purple will work in a regular computer setup, you will run a much higher risk of data corruption.

[newpball]

Different hard drives are suitable for different things.

This is my personal drive policy:

Operating System
SATA SSD drives only.

Right now interfacing it is a mess, SATA standards have not kept up with new technology.
PCIe based M.2 is much faster but we still have to deal with this ridiculous AHCI bottleneck.

This is going in the right direction:
http://www.extremetech.com/computing/197051-samsung-announces-new-pcie-3-0-ssd-breakin...rmance-barrier

Work and scratch drives
Fast 7200 drives, I like the 1 TB WD Black drives for this.
Soon I will use SDD drives as work drives, prices come down hard and the increased speed is dramatic. For scratch drives there is no need. And yes, if you work with HD there is no reason not to load your computer with at least 32GB of memory, it will certainly unload the scratch drive usage.

Semi-permanent storage
Large reliable 5200 drives. 3-4TB. I prefer the WB Red drives.
Slow is good here, less movement and less heat!

[fritzi93]

Does anyone know if these can be used in a desktop? They use a SATA interface, so I'm assuming that they should work with a home pc.

I don't see why not. WD has offered "Surveillance Storage", 24/7 drives for quite some time. I have one (now in the wife's computer) that's at least 8 years old (320 GB) and still works.

Never heard before about a higher risk of data corruption.

[sophisticles]

Never heard before about a higher risk of data corruption.

That doesn't make much sense does it? You can use it to continuously write data to it 24/7 but if you use it in a desktop scenario where you are not constantly writing data to it somehow this increases the risk of data corruption?

[hello_hello]

Seems to me that these drives would be perfect for a video workstation, or any other PC for that matter. I read somewhere that these drives are rated for 180tb worth of writes per year, which means they should be really durable.

No, we've only recently learned recently that's simply not true.

I use the very fast WD Black drives as a work drive, they are advertised as very reliable but in my experience you cannot expect any drive to last longer than a year if you use them for heavy video or image editing.

I don't see why not. WD has offered "Surveillance Storage", 24/7 drives for quite some time. I have one (now in the wife's computer) that's at least 8 years old (320 GB) and still works.

I have WD 320GB "consumer grade" drives of the same age still going strong. I'm a little sceptical when it comes to surveillance class and enterprise class etc in respect to greater longevity.

Never heard before about a higher risk of data corruption.

Yeah, that one smells like typical forum B.S.

[newpball]

There are two "issues" with the purple drive, it presumably uses the ATA streaming feature which guarantees that data is written in a certain time interval but with the catch that it is less reliable and second it lacks RAFF, a kind of vibration resistance.

[drjtech]

UserBenchmark rates WD Purple as "Very Poor" for desktop use:

http://hdd.userbenchmark.com/Compare/WD-Purple-2TB-2014-vs-Seagate-Desktop-SSHD-1TB/2662vs1784

The WD Purple is a surveillance drive with low power consumption and a design that's optimized for 24x7 operation. There is actually little beyond marketing that separates the Purple from the Red and Green drives. They all share almost identical hardware. The thing that does differentiate the Purple drives is their firmware which supports AllFrame, a surveillance specific feature. Allframe handles the cache in a way that is optimized for video streams. The AllFrame technology however is only enabled when used in conjunction with a supported host controller, most of which are only found in dedicated NVR (Network Video Recording) devices. As a result there is no benefit in using this drive in a HTPC to record video streams, because the surveillance specific functions won't be enabled. In terms of effective speed the Purple lags the new Red and Green drives by around 26%.

WD markets Purple drives for video surveillance because that is what they were designed and engineered for.

[fritzi93]

Well, this is very interesting and I've learned something new today. I read the previous links (thanks all) and found a few more. Here's Tom's Hardware and their shootout comparing surveillance drives from WD and Seagate:

http://www.tomshardware.com/forum/292184-32-partition-table#6100497

If you read the whole thing, it's clear that they prioritize writes. If the drive is stressed (too many cameras), the first thing to suffer will be reads. So the guy watching the security monitor will be the first to know. Makes sense. But that's not quite the same thing as claiming they are more prone to data corruption. The shootout didn't mention that at all, just the write prioritizing.

I suppose in the sense that if overloaded it will start losing data as it continues to write, then yeah.

A couple posters in the Tom's hardware forum asked questions similar to the OP's.

http://www.tomshardware.com/forum/292184-32-partition-table#6100497

http://www.tomshardware.com/answers/id-2399758/2tb-purple-surveillance-hdds-work-deskt...ard-drive.html

In the comments on the shootout article, one guy asked, for surveillance, why not use some plain vanilla drives in a couple RAID arrays, mirrored. If you insist on best reliability without breaking the bank on enterprise drives, why not indeed?

My takeaway is that you can use it in your computer okay, but it's not the best choice. It's slower, for one thing, as already mentioned by drjtech.

[nic2k4]

I read somewhere that these drives are rated for 180tb worth of writes per year, which means they should be really durable.

They're not the only ones with that same rating.

That doesn't make much sense does it? You can use it to continuously write data to it 24/7 but if you use it in a desktop scenario where you are not constantly writing data to it somehow this increases the risk of data corruption?

As newpball pointed out they use the ATA streaming command set, the datasheet calls it Silkstream. It says the error correction is tuned for streaming making it less suitable for general use.

[hello_hello]

As newpball pointed out they use the ATA streaming command set, the datasheet calls it Silkstream. It says the error correction is tuned for streaming making it less suitable for general use.

It says SilkStream is compatible with the ATA streaming command set but I couldn't see any mention of error correction or a statement SilkStream makes a drive less suitable for general use. newpball has claimed that makes them less reliable but with no explanation as to why, so it belongs in the "grain of salt" category. Are there any other ATA standards that make drives less reliable under normal use?

Smooth Stream™ Technology in HGST Hard Disk Drives
The new Streaming Command Set included in the ATA/ATAPI-7 standard2 provides a comprehensive set of
tools for disk drives used in audio/video applications. The ATA Streaming command Set includes:
• Streaming Performance Log—describes normal drive performance
• Error Recovery Time Limits—prevents long delays for error recovery handling
• Continuous Read/Write Controls—used to return/use partially correct data
• Streaming Error Logs—reduces time delays otherwise incurred in system error processing
• Configure Stream Command—allows optimum drive buffer management for AV streams
• Delayed Sector Log—documents relocated sectors that requires additional read/write processing time
• Handle Stream Error—enables full error recovery for computer data during AV streaming operations

[nic2k4]

Of course an explanation would have been helpful, but all the manufacturers make it so difficult to get any the best you can do is read between the lines and hope someone will come along with an actual answer.

So reading the Smooth Stream white paper you find out that for this type of drive it's more important to maintain the data stream than have quality data. However, it is capable of doing the full error recovery procedure if the HSE command is issued by the system. The question is does an OS normally issue the command?

I did some more digging and finally found what I guess is as close to a definitive answer from someone who should know.

[hello_hello]

I did some more digging and finally found what I guess is as close to a definitive answer from someone who should know.

Yep, that'd be my interpretation. Unless the host controller supports the streaming ATA commands the drive pretty much behaves like any other hard drive. No less reliable. I doubt the typical PC ATA controller would support it.

And from the white paper you linked to:
"HGST drives that support Smooth Stream are also optimized for consumer applications that require reliable storage for audio and video files."

Not that I know what "optimized for consumer applications" means exactly, but it seems to imply the opposite of "less reliable".