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  Previous versions of Bifurcator's message #11286702 « External HD crashed »

  

Bifurcator
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Upload & Sell: On
Re: External HD crashed


15Bit wrote:
I don't think i'd choose to boot from an external drive, but if it works well for you who am i to criticise?

I've figured out why your RAID seems oddly fast to me - average sequential transfer rates on those drives is around 150-160MB/sec, but peak (outer sectors i expect) is close to 200MB/sec. I guess that you are using the outer sectors for that test. Even 150MB/sec is pretty damn fast mind

There are a couple of advantages to SSD's not related to performance - in a laptop they are more tolerant to being thrown around than spinning disks, and they use less power. Comparing my SSD-equipped laptop with my colleague's equivalent with a spinning disk i get about an extra 45-60 mins battery life. Not to be sniffed at...


Of course, HDDs are only used to 60% (to 75% max) capacity unless you're in a pinch for the space or something. So always outer cylinders! Also when your drives start getting up around 75% full and past that's when trouble starts happening. I dunno why and the trouble are various but that's fairly well known common info I think.

Yup! SSDs are awesome in laptops and notebooks!! No arguments there. Still, I think I would rater go with 72000 SSHD in a laptop myself.








Bifurcator wrote:


Here's what the 2-drive 6TB RAID0 stripes profile like. This is with lots of data already on too.
With a 3-drive RAID0 stripe I get about 750MB/s and with four drives I get close to 1GB/s.
And of course with 4 of these drives we are talking about 12TB of storage space for $400.




Aaron D wrote:
Holy crap! 500+ MB/s write on a 2 drive RAID0?

I have a question for you sir. I have been toying with the idea of building something to capture uncompressed 1080 video. We're talking close to 200MB/s of bandwidth at 24bits of color depth. What kind of write speed are you getting on files in excessive size? Say 500MB and up? Have you tested sizes this large Bif? These are 'cudas, correct?

How are you getting 200+MB/s out of a single, rotary type, HDD What kind of controller are you using if I may ask?


I get the same for large files; about 4000MB/s when I drag and drop files over 5GB and time it. The controller isn't important here I think. I guess any decent on-board controller from 2010 onward will do the job fine. Most of them are 6Gb per SATA port and that works out to a max of about 560MB/s real-world with probably a system bandwidth limit of around 1.6GB/s. The controller in this particular box is 3Gb and the real-world limits are 285MB/s per drive port with a system limit of about 880 to 900MB/s and even that is enough for uncompressed 2K 4:4:4 12bit. With just these two drives I can almost get there now. I can do about 20fps at that and achieve the fell 24fps if I drop it down to 10bit - still within most professional editing standards (see below).

I think the drives are maybe the most critical factor these days. As mentioned I's using the Seagate Barracuda ST3000DM001 drives. I had just finished reading a tech write-up on these which praised them for for their near workstation grade specs when I saw a pile of them at a regular department store for 9,000 (about $100) each so I bought the lot of them. I think those prices are reproducible with a little mouse-work tho. Here's what the system reports on one of them:

      ST3000DM001-1CH166:

      Capacity: 3 TB (3,000,592,982,016 bytes)
      Model: ST3000DM001-1CH166
      Revision: CC43
      Serial Number: Z1F0VHVT
      Native Command Queuing: Yes
      Queue Depth: 32
      Removable Media: No
      Detachable Drive: No
      BSD Name: disk5
      Rotational Rate: 7200
      Medium Type: Rotational
      Bay Name: Bay 2
      Partition Map Type: GPT (GUID Partition Table)
      S.M.A.R.T. status: Verified

      Volumes:
      disk5s1:
      Capacity: 209.7 MB (209,715,200 bytes)
      BSD Name: disk5s1
      Content: EFI
      disk5s2:
      Capacity: 3 TB (3,000,249,008,128 bytes)
      BSD Name: disk5s2
      Content: Apple_RAID
      Boot OS X:
      Capacity: 134.2 MB (134,217,728 bytes)
      BSD Name: disk5s3
      Content: Apple_Boot



Jan 21, 2013 at 05:31 AM
Bifurcator
Offline
Upload & Sell: On
Re: External HD crashed


15Bit wrote:
I don't think i'd choose to boot from an external drive, but if it works well for you who am i to criticise?

I've figured out why your RAID seems oddly fast to me - average sequential transfer rates on those drives is around 150-160MB/sec, but peak (outer sectors i expect) is close to 200MB/sec. I guess that you are using the outer sectors for that test. Even 150MB/sec is pretty damn fast mind

There are a couple of advantages to SSD's not related to performance - in a laptop they are more tolerant to being thrown around than spinning disks, and they use less power. Comparing my SSD-equipped laptop with my colleague's equivalent with a spinning disk i get about an extra 45-60 mins battery life. Not to be sniffed at...


Of course, HDDs are only used to 60% (to 75% max) capacity unless you're in a pinch for the space or something. So always outer cylinders! Also when your drives start getting up around 75% full and past that's when trouble starts happening. I dunno why and the trouble are various but that's fairly well known common info I think.

Yup! SSDs are awesome in laptops and notebooks!! No arguments there. Still, I think I would rater go with 72000 SSHD in a laptop myself.


Aaron D wrote:
Bifurcator wrote:


Here's what the 2-drive 6TB RAID0 stripes profile like. This is with lots of data already on too.
With a 3-drive RAID0 stripe I get about 750MB/s and with four drives I get close to 1GB/s.
And of course with 4 of these drives we are talking about 12TB of storage space for $400.





Holy crap! 500+ MB/s write on a 2 drive RAID0?

I have a question for you sir. I have been toying with the idea of building something to capture uncompressed 1080 video. We're talking close to 200MB/s of bandwidth at 24bits of color depth. What kind of write speed are you getting on files in excessive size? Say 500MB and up? Have you tested sizes this large Bif? These are 'cudas, correct?

How are you getting 200+MB/s out of a single, rotary type, HDD What kind of controller are you using if I may ask?


I get the same for large files; about 4000MB/s when I drag and drop files over 5GB and time it. The controller isn't important here I think. I guess any decent on-board controller from 2010 onward will do the job fine. Most of them or 6Gb per SATA port and that works out to a max of about 500MB/s real-world with probably a system bandwidth limit of around 1.5GB. The controller in this particular box is 3Gb and the real-world limits are 285MB/s per drive port with a system limit of about 880 to 900MB/s and even that is enough for uncompressed 2K 4:4:4 12bit. With just these two drives I can almost get there now. I can do about 20fps at that and achieve the fell 24fps if I drop it down to 10bit - still within most professional editing standards (see below).

I think the drives are maybe the most critical factor these days. As mentioned I's using the Seagate Barracuda ST3000DM001 drives. I had just finished reading a tech write-up on these which praised them for for their near workstation grade specs when I saw a pile of them at a regular department store for 9,000 (about $100) each so I bought the lot of them. I think those prices are reproducible with a little mouse-work tho. Here's what the system reports on one of them:

      ST3000DM001-1CH166:

      Capacity: 3 TB (3,000,592,982,016 bytes)
      Model: ST3000DM001-1CH166
      Revision: CC43
      Serial Number: Z1F0VHVT
      Native Command Queuing: Yes
      Queue Depth: 32
      Removable Media: No
      Detachable Drive: No
      BSD Name: disk5
      Rotational Rate: 7200
      Medium Type: Rotational
      Bay Name: Bay 2
      Partition Map Type: GPT (GUID Partition Table)
      S.M.A.R.T. status: Verified

      Volumes:
      disk5s1:
      Capacity: 209.7 MB (209,715,200 bytes)
      BSD Name: disk5s1
      Content: EFI
      disk5s2:
      Capacity: 3 TB (3,000,249,008,128 bytes)
      BSD Name: disk5s2
      Content: Apple_RAID
      Boot OS X:
      Capacity: 134.2 MB (134,217,728 bytes)
      BSD Name: disk5s3
      Content: Apple_Boot



Jan 21, 2013 at 05:28 AM
Bifurcator
Offline
Upload & Sell: On
Re: External HD crashed


15Bit wrote:
I don't think i'd choose to boot from an external drive, but if it works well for you who am i to criticise?

I've figured out why your RAID seems oddly fast to me - average sequential transfer rates on those drives is around 150-160MB/sec, but peak (outer sectors i expect) is close to 200MB/sec. I guess that you are using the outer sectors for that test. Even 150MB/sec is pretty damn fast mind

There are a couple of advantages to SSD's not related to performance - in a laptop they are more tolerant to being thrown around than spinning disks, and they use less power. Comparing my SSD-equipped laptop with my colleague's equivalent with a spinning disk i get about an extra 45-60 mins battery life. Not to be sniffed at...


Of course, HDDs are only used to 60% (to 75% max) capacity unless you're in a pinch for the space or something. So always outer cylinders! Also when your drives start getting up around 75% full and past that's when trouble starts happening. I dunno why and the trouble are various but that's fairly well known common info I think.

Yup! SSDs are awesome in laptops and notebooks!! No arguments there. Still, I think I would rater go with 72000 SSHD in a laptop myself.



Jan 21, 2013 at 04:06 AM



  Previous versions of Bifurcator's message #11286702 « External HD crashed »