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RAID 0 with 4x, 3x or 2x WD Red?

mikaelmsk
Level 7
Hello,

I'm building a new computer and I will use a SSD for operating system and another volume with WD Red drives on RAID 0 Red formy files.

I'll use a backup solution with a 4TB external USB 3.0 HDD, so I'm choosing the RAID 0 for more performance.

Note: My motherboard supports up to 4 HDDs in SATA III 6 Gbps (Asus Rampage IV Extreme).

My question is whether it is worth doing RAID 0 with 4 HDDs WD Red, or if the gain with 4 HDDs is very small in relation to use RAID 0 with 3 or 2 HDDs.

Whith 4 WD Red on RAID 0 can I get close to the transfer rate of the SSDs, that are around 400 MB/s?

Has anyone done tests with 2, 3 and 4 HDDs on RAID 0?

Thank you!
8,476 Views
7 REPLIES 7

HiVizMan
Level 40
Actually you are sort of correct.

You have two Intel 6GB SATA ports. These are perfect for SSD and RAID boot drive.

The other 2 are Asmedia - you can use these as a software RAID but not as a hardware RAID

The black ports are the 4 3G Intel SATA connectors and will be ideal for 4 hard drive RAID array.

Page 2-25 to 2-28 in the manual refer.
To help us help you - please provide as much information about your system and the problem as possible.

HiVizMan wrote:
Actually you are sort of correct.

You have two Intel 6GB SATA ports. These are perfect for SSD and RAID boot drive.

The other 2 are Asmedia - you can use these as a software RAID but not as a hardware RAID

The black ports are the 4 3G Intel SATA connectors and will be ideal for 4 hard drive RAID array.

Page 2-25 to 2-28 in the manual refer.


I understand that the Asus Rampage IV Extreme has 4x internal SATA III (Red) and 2x external eSATA III. I'm wrong?

26840

nleksan
Level 10
I would like to make a suggestion, and that would be to not use the Reds for (local) RAID, and instead grab some of the Western Digital Blue 1TB WD10EZEX drives for local RAID.

The Reds are designed more for NAS/SAN storage, and have a lower spindle speed (5900rpm) than the Blues.

Most importantly, though, is that the Blues are the only 7200rpm drives from WD to use single 1TB platters, meaning only 1 platter per drive. The benefits of this are, aside from tremendously impressive R/W speeds (sequentially), the large reduction in total moving parts which imparts a greater reliability as is inherent to any mechanical device, they run silently, they run extremely cool, they cost as little as $50 a piece...

I have quite a large number of them across a few systems, running single drives and arrays, and have run up to 6 of them in RAID0 in a single system. Throughput exceeded 1.2GB/sec sequentially on the outer third of the disks (about 1.6TB worth of data at that speed).

Newer revisions (anything you'll get nowadays) greatly improved upon the only real downside of the drive initially, which was the rather poor access times; originally they were around 19-21ms, but of all my drives, the range is from as little as 12.9ms to, at most, 14.2ms.


Running 4 in RAID0, you're best bet is to partition the array to have a ~1TB and a ~3TB (each) pair of partitions, with the 1TB partition being on the outer edge of the drives.
This is essentially short-stroking, but without losing the inner-platter area's capacity. You would want to use the smaller (outer) partition for games, common programs, etc due to the drives being within their "super-sweet-spot".

Here's an HDTune Pro run I JUST did of one of my single-drive WD10EZEX, short-stroked to 250GB to emulate the 1TB/3TB partitioning; you just multiply the numbers by about 3.6-3.8 to get 4x RAID0 speeds...
Oh, and this is with FOUR programs running constant I/O requests to and from the drive, while the benchmark was run, to show you "worst case scenario".....

26827


and from the log....

HD Tune Pro: WDC WD10EZEX-60ZF5A0 Benchmark

Test capacity: 250 gB

Read transfer rate
Transfer Rate Minimum : 148.0 MB/s
Transfer Rate Maximum : 201.7 MB/s
Transfer Rate Average : 183.3 MB/s
Access Time : 10.1 ms
Burst Rate : 374.2 MB/s
CPU Usage : 0.8%



(note: the minimum is not representative of real-world results; I goofed during the start of the run and it caused that initial big dip you see).


Un-loaded, the average is around 192MB/sec.... With four in RAID0, I get about 786MB/sec Read, 802MB/sec Write, and access times of 9.2ms running a fast outer and slower inner partition.

(Note that you also should use the internal platter space for static storage; you do not want to be accessing stuff from both partitions concurrently)

nleksan wrote:
I would like to make a suggestion, and that would be to not use the Reds for (local) RAID, and instead grab some of the Western Digital Blue 1TB WD10EZEX drives for local RAID.

The Reds are designed more for NAS/SAN storage, and have a lower spindle speed (5900rpm) than the Blues.

Most importantly, though, is that the Blues are the only 7200rpm drives from WD to use single 1TB platters, meaning only 1 platter per drive. The benefits of this are, aside from tremendously impressive R/W speeds (sequentially), the large reduction in total moving parts which imparts a greater reliability as is inherent to any mechanical device, they run silently, they run extremely cool, they cost as little as $50 a piece...

I have quite a large number of them across a few systems, running single drives and arrays, and have run up to 6 of them in RAID0 in a single system. Throughput exceeded 1.2GB/sec sequentially on the outer third of the disks (about 1.6TB worth of data at that speed).

Newer revisions (anything you'll get nowadays) greatly improved upon the only real downside of the drive initially, which was the rather poor access times; originally they were around 19-21ms, but of all my drives, the range is from as little as 12.9ms to, at most, 14.2ms.


Running 4 in RAID0, you're best bet is to partition the array to have a ~1TB and a ~3TB (each) pair of partitions, with the 1TB partition being on the outer edge of the drives.
This is essentially short-stroking, but without losing the inner-platter area's capacity. You would want to use the smaller (outer) partition for games, common programs, etc due to the drives being within their "super-sweet-spot".

Here's an HDTune Pro run I JUST did of one of my single-drive WD10EZEX, short-stroked to 250GB to emulate the 1TB/3TB partitioning; you just multiply the numbers by about 3.6-3.8 to get 4x RAID0 speeds...
Oh, and this is with FOUR programs running constant I/O requests to and from the drive, while the benchmark was run, to show you "worst case scenario".....

26827


and from the log....

HD Tune Pro: WDC WD10EZEX-60ZF5A0 Benchmark

Test capacity: 250 gB

Read transfer rate
Transfer Rate Minimum : 148.0 MB/s
Transfer Rate Maximum : 201.7 MB/s
Transfer Rate Average : 183.3 MB/s
Access Time : 10.1 ms
Burst Rate : 374.2 MB/s
CPU Usage : 0.8%



(note: the minimum is not representative of real-world results; I goofed during the start of the run and it caused that initial big dip you see).


Un-loaded, the average is around 192MB/sec.... With four in RAID0, I get about 786MB/sec Read, 802MB/sec Write, and access times of 9.2ms running a fast outer and slower inner partition.

(Note that you also should use the internal platter space for static storage; you do not want to be accessing stuff from both partitions concurrently)


Thanks nleksan for the quality of your reply and the tests you did! It really helped me a lot!

This WD Blue is very interesting by the price and the performance, is undoubtedly better than the WD Red. but..

In the Western Digital site, the WD Blue has a note that it is not recommended for RAID. You know why that is? Below is the link and the text from the site.

http://www.wdc.com/en/products/products.aspx?id=770

"WD Blue hard drives are tested and recommended for use in PCs, industrial applications, notebooks, netbooks and external enclosures.*
*Desktop drives are not recommended for use in RAID environments, please consider using WD Red hard drives for home and small office 1-5 bay NAS systems and WD Enterprise hard drives for rackmount and >5 bay NAS systems"

Thanks!

HiVizMan
Level 40
Real quality reply my friend. I have repped you.
To help us help you - please provide as much information about your system and the problem as possible.

HiVizMan
Level 40
For your mechanical hard drive you will or rather you can use all 4 SATA 3G ports for any of the supported RAID arrays. There would be no benefit in using a SATA6G port for a mechanical drive when no mechanical drive array will max out a 3G port.
To help us help you - please provide as much information about your system and the problem as possible.

nleksan
Level 10
The reason WD doesn't "recommend them for RAID" is that they no longer provide TLER support with any of their consumer drives barring the Reds ("Time Limited Error Recovery", essentially how long the drive will make a RAID controller "wait" before saying "nothing to see here, move along" when encountering an error).

I have never found this to be an issue with smaller arrays, much less those built knowing full-well that data loss was probable (which is the case for any RAID0 array; it WILL fail, the only question is how long).