Brian

Seagate Promotes SmartAlign Software

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The hard drive industry is currently transitioning from a traditional 512-byte sector to a new Advanced Format with a 4kb sector. Seagate Technology will be introducing its SmartAlign technology to its new Advanced Format hard drives to help customers with the transition.

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The truly amazing thing to me about Seagate's magical SmartAlign Technology is how many times they can mention it without ever saying a bloody thing of any consequence.

Has anyone anywhere said anything about how SmartAlign works? What does it actually do? If so, will you please step forward and share? wink.gif

It as though all tech reporting boils down to now is rewording press releases. Sheesh.

-irrational john

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We've talked about this some around the Western Digital 4K drive, but it basically makes sure the sectors are properly aligned for 4K writes. Misalignment problems can result in slow write times, inefficient disk operation and generally poor performance. We see this in our tests of 4K physical and 4K logical drives. This also applies to SSDs where poor alignment can lead to extra read/write activity. Alignment software properly realigns partitions to 4k sector boundaries.

I'm fairly certain the tools are made by Paragon, so you can actually buy this yourself through their disk management software if you want to play around with it.

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it basically makes sure the sectors are properly aligned for 4K writes.

Yes, of course. But again the question I would like asked is how does Seagate's SmartAlign do this?

I'm familiar with the utilities that Western Digital makes available and in that case I understand that they essentially relocate partitions so that they are properly aligned. However, Seagate appears to claim that this separate step does not need to be done with their SmartAlign thingee. For example,

Seagate's SmartAlign technology automatically manages misaligned partitions in real-time inside the hard drive
without the need for any software utilities
.

So, what's up with that? Nobody seems to bother to ask ... sad.gif

What exactly is Seagate claiming? Just plug one of their 4K drives into a Windows XP system, format it, and it "just works"? blink.gif

-irrational john

Edited by irrational John

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Yes, I see your point. With the WD Align tool you have to run that manually. We'll dive more into how the Seagate tool works when the drive is released.

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So, what's up with that? Nobody seems to bother to ask ... sad.gif

What exactly is Seagate claiming?

Completely agreed. Uncritically reprinting Seagate's press release without asking this question reflects poorly on SR.

A rather evil, but effective way to do this would be to parse the partition table and rotate the partition by the number of sectors required to align it.

I.e. if a partition occupies LBAs 63 through 1,000,062, then offset it by 1 sector to apply the following mapping:

  • LBA 63..70 → Block 64..71 (4K sector 8)
  • LBA 71..78 → Block 72..79 (4K sector 10)
  • LBA 1,000,047..1,000,054 → Block 1,000,048..1,000,055 (4K sector 125006)
  • LBA 1,000,055..1,000,061 → Block 1,000,056..1,000,062 (7/8 of 4K sector 125007)
  • LBA 1,000,062 → 63 (1/8 of 4K sector 7)

You wouldn't lose any capacity, just trade efficient access to the partition for very inefficient access to the last (probably unused) sector in it.

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A rather evil, but effective way to do this would be to parse the partition table and rotate the partition by the number of sectors required to align it.

I doubt that Seagate would want to do anything as implementation dependent as reading a partition table. That requires too many assumptions about how the drive might be used. I think Seagate would want to keep SmartAlign as dumb as they could. :rolleyes:

My guess ... and since I can't find any info anywhere guessing is all I've got ... is that Seagate just added extra smarts to their caching algorithms to ensure that they do as few "read & modify & rewrite" writes as possible. But I have to wonder if it were so "easy" to "fix" things why wouldn't Western Digital have also done that? So I'm probably missing something ...

-irrational john

Edited by irrational John

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