Seagate Ironwolf ST3000VN007 vs ST3000VN006

Akash jain Estimated Read Time: 1 Minutes

The new 3TB Ironwolf ( ST3000VN006) has 2 platters and it will replace the older 3 platter part number ( ST3000VN008).

Having one less platter means that ST3000VN006 is lighter and has better engery efficiency ( even if only marginally ).  Transfer rates of new part number are up from 180 MB/s of earlier one to 202 MB/s.

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Seagate ST4000VN006 vs ST4000VN008

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4TB Ironwolf has a new part number ST4000VN006 - the 2 platter drive and it will replace the ST4000VN008 part number soon.

Main difference is that ST4000VN006 has 2 disk platters, in contrast to 3 platters of ST4000VN008.  This means that the new part number is marginally ligher and energy efficient.  The new part number also has a better transfer rate (202 MB/s compared to 180 MB/s of earlier one)

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WD63PURZ vs WD62PURZ

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WD has introduced another part number for 6TB Purple. We already had WD60PURZ and WD62PURZ and now there is WD63PURZ

First of all , it is a CMR drive like WD60PURZ and WD62PURZ. The WD63PURZ has the largest cache (256 MB). The power consumption is lower on the WD63PURZ, probably because of the smaller number of platters.

Here is a table with a summary of the main differences. 

 

WD60PURZ

Wd62PURZ

WD63PURZ

Recording

CMR

CMR

CMR

Cache (MB)

64

128

256

Annual Workload

180TB

180TB

180TB

Read/Write Average power

5.3W

6.2W

4.6W

Weight(Gms)

750 gms

720 gms

570 gms

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WD

Magic of RAID parity and Failure tolerance of ANY drive in an array

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RAID 1 is easy to understand. 2 hard drives mirrored to each other. Call it cloning, bit-for-bit copy, exact copy or mirroring, it is easy to visualise.

But if you try to apply the same analogy to, say, RAID 5, it defies logic. We have been asked this question so many times that we finally decided to write this article for everyone who is curious about how RAID 5 works.

Let us look at RAID5 - you are told that if ANY of the drives in RAID5 fail, you can recover your data. So if you have 4 drives in a RAID 5 and ANY 1 drive fails, you can logically recover data/rebuild. how can 1 drive store the data of the other 3 drives.

That's the problem - how is the data in an array of 4 drives distributed so that ANY 1 drive can fail without affecting the data.

The magic is in the parity bit of RAID. The easiest way to understand parity is to think of it as a sum of all the values . Let me first give you an analogy.

Let us say you have 4 cards, each with a number and a 5th card with the sum of all the numbers (marked to show that ). Now if one card fails, any card, you can easily infer the number that card would have had.

CARD 1
CARD 2
CARD 3
CARD 4
CARD 5
4
7
3
2
Sum= 16

 
So if card 1 is missing in the above figure, you can derive the value to 16- (7+3+2) = 4.

CARD 1
CARD 2
CARD 3
CARD 4
CARD 5
?
16-(7+3+2)
7
3
2
Sum= 16

 

Similarly card 2 data can be derived with 16- (4+3+2)= 7 . Same for card 3 and 4. This is a greatly simplified version of how RAID 5 works.  Actual RAIDs use XOR operation to calculate the parity bit, unlike the sum in our example.

RAID5 has just 1 parity bit calculated with XOR and RAID 6 has 2 parity bits. With XOR you can not only calculate the parity bit, but also do the reverse calculation easily.

We will not go into the technical details of the XOR operation here, which is one of the many functions used to calculate parity, as there are already very good articles on the internet explaining this. But we hope that our missing card analogy, with the sum known will give you an idea of the logic behind RAID parity.  RAIDs are a great way to protect you against hardware failure and hopefully you know now how they work.

 

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WD Ultrastar 20TB HC560 drives available now

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WD Ultrastar HC560- 20TB drives are available now, not long after Seagate introduced its 20TB drives.

Just like the Ultrastar 18TB, these are 9 platter drives. WD was able to increase the data storage on 9 platters to 20TB without resorting to SMR, but rather with using optiNAND to store part data.

iNAND is used to store the data about the data (metadata), and the disks are used to store the actual data. The result is a CMR 20TB drive with 2.2TB per platter.

Other than that, they are the same as other Ultastar drives - helium sealed to reduce drag (all 12TB+ drives are currently helium sealed), 3.5" form factor, available in SATA and SAS, 5-year limited warranty, 2.5M hours MTBF, etc.

As with all large capacity hard drives, transfer speeds do not keep pace with increased capacity. This drive is not an exception - it has the same transfer speed as the 18TB drive.

We have these drives in stock now.

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WD

Seagate ST3000VN006 vs ST3000VN007

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TL; DR: ST3000VN006 has higher cache, higher transfer rate and lower RPM. Both ST3000VN006 and ST3000VN007 are CMR .

Seagate announced the introduction of a new model on 3TB Ironwolf - ST3000VN006, replaicing the old ST3000VN007.

The new model ST3000VN006 is lighter in weight and has a thinner profile, which means it has a smaller number of platters compared to ST3000VN007

What has changed

  • ST3000VN006 has a higher transfer rate (202 MB/s) compared to ST3000VN007 (180 MB/s)
  • ST3000VN006 has a higher cache 256 MB , compared to 64MB of the ST3000VN007
  • ST3000VN006 spins at 5400RPM, slower than ST3000VN007 which used to be 5900 RPM.

Higher data transfer rates despite lower spindle speed is mostly due to the higher track density on the newer drives. Apart of these features, everything else seems to be the same - warranty, rescue services etc have remained unchanged.

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Seagate ST4000VN006 vs ST4000VN008

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Both the drives are CMR, ST4000VN006 is the newer model with higher cache, higher transfer rate and lower RPM and has lesser number of platters.

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Ironwolf Pro 20TB (ST20000NE000) Launched

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Seagate announced the launch of its 20TB Ironwolf Pro on December 2. They are the first vendor to announce the availability and specifications of these hard drives.

As with the other Ironwolf Pro drives, this drive comes with a 5-year limited warranty with 3 years of data recovery service. For 12TB and above, there are only Pro drives, meaning for 20TB there is only a PRO version (although an Exos version may be coming soon).

According to the spec sheet, it offers CMR recording, 300TB annual workload, and a maximum transfer rate of 285MB/s. 20TB / 18.30TiB could could probably have the lowest cost per TB in future, even if the launch price puts the cost per TB higher than 18TB.

We have already placed orders with Seagate for this drive and should have it on the shelves by mid-December.

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Seagate ST4000VX007 vs ST4000VX013

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How is the old ST4000VX007 part number different from the new ST4000VX013

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Seagate 7E10 vs 7E8

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7E8 had 8TB as its highest capacity. For 10TB, of course, there was the X10 platform. Now there is the 10TB capacity also on X10 and 7E10

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