SSD Alignment Issue after clone - Must Read if you have cloned your SSD

charold

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So, I recently upgraded from an Intel 320 120GB SSD to an Intel 520 180GB SSD. Rather than reinstall (reinstall was done about 3 months ago) I decided to clone and resize partitions.

Long story short, when running benchmarks I noticed AS SSD said "160650 K -BAD". Upon research I found out this was a misalignment of partitions because I had cloned my SSDs. I came across the Paragon Alignment Tool 3.0, which I installed, it then found the issue, and fixed it upon a reboot (I let it run at work so I'm not sure how long it took). Once I came home I noticed immediate improvement in logging in even which I was surprised about.

I reran AS SSD and Crystal Mark Disk and was amazed at the differences! Here's a link to pre and post alignment benchmarks.

Imgur Album

Pre Alignment (notice the 160650 K- BAD on AS SSD)



Post Alignment


Anyone else have this issue? Very happy with the results myself.
 

mwroobel

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What app did you use to clone the drive? Most of the newer cloning apps are SSD aware, some of the older ones are not.
 

charold

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It was Clonezilla off a fairly old boot disc I had lying around (didn't have any spare CD-Rs). I wanna say it was around 4-5years old
 

ckryan

SSD Abuser
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It was Clonezilla off a fairly old boot disc I had lying around (didn't have any spare CD-Rs). I wanna say it was around 4-5years old

That would be the issue. Paragon's alignment tool is good though, and handy when migrating from a legacy XP system with recovery partitions etc.
 

charold

Limp Gawd
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I'll have to do some more research into how SSD's work because I still don't quite understand why the clone would have caused that issue.
 

af22

Gawd
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the most fail safe way is to use the windows backup and restore. i think the problem with the utilities is it doesn't put proper padding in front of your partition. i've cloned my drive quite a few times now after upgrading from an ocz agility -> crucial m4 -> samsung 830. with some of the 3rd party software, after you do the clone, i still need to boot from a windows disk to perform a startup repair. i found using the built in windows backup and restore is the fastest and easiest way.
 

Forceman

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Yeah, you need to use a SSD aware cloning tool to do it - that old version of clonezilla was your problem. A new program will take care of the alignment automatically.
 

Unknown-One

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Finally decided to be un-lazy and align my SSD. Results?

Before:


After:


Pretty much everything is faster, but my sequential read speeds actually went DOWN? What's the deal there? :confused:
 

mwroobel

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Finally decided to be un-lazy and align my SSD. Results?


Pretty much everything is faster, but my sequential read speeds actually went DOWN? What's the deal there? :confused:
Quite honestly, a 4% difference in STR is not statistically significant, and will have no real life difference. With the big gains from proper alignment you are better off even if there was a 5% decrease in STR. People put too much weight on benchmarks, which can vary up to 5% per run, which is why you should do 4 or 5 iterations and average them.
 

WillC310

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FWIW Acronis True Image Home 2012 is SSD friendly. I cloned from a 120G Vertex to a 240G Sandisk Extreme and it handled it fine.
 

Unknown-One

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Quite honestly, a 4% difference in STR is not statistically significant, and will have no real life difference. With the big gains from proper alignment you are better off even if there was a 5% decrease in STR. People put too much weight on benchmarks, which can vary up to 5% per run, which is why you should do 4 or 5 iterations and average them.
Erm... I wasn't actually all that concerned with the speed, the drive is now much faster overall.

I was more concerned with the technical reasons behind the change. By all accounts, speed should be higher across the board with a correctly aligned drive. Why would sequential speeds actually drop measurably?
 

af22

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Erm... I wasn't actually all that concerned with the speed, the drive is now much faster overall.

I was more concerned with the technical reasons behind the change. By all accounts, speed should be higher across the board with a correctly aligned drive. Why would sequential speeds actually drop measurably?
Because your not supposed to run AS SSD benchmark repeatedly! It puts unnecessary wear and tear. Did you run a sanity erase or zero out the space before you realigned?
 

Unknown-One

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Because your not supposed to run AS SSD benchmark repeatedly! It puts unnecessary wear and tear. Did you run a sanity erase or zero out the space before you realigned?
I didn't run it repeatedly... I ran it once, waited a few days, aligned the drive, then ran it again to check the changes. Perfectly reasonable usage.

TRIM has been active since day-one, so empty space was already nice and blank pre-alignment.

So yeah, my original question... what causes sequential reads to be slower on some drives vs. the same drive in an un-aligned state? Something to do with the controller now allocating more time to random I/O? The OP actually saw sequential speeds improve, so this effect seems to vary from drive-to-drive... I'm curious to know what's going on inside the SSD here.
 

Forceman

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I think you are reading too much into that one number. Possibly some other background task accessed the drive during that portion of the test, which made the score go down a little bit. Maybe the test itself has that much variation between runs. Did you try it again to see if you get the same numbers?

I'm not sure alignment has anything to do with reads at all - it puts a penalty on writes because you are writing to two blocks every time instead of one, but it really shouldn't matter for reads.
 

Unknown-One

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Did you try it again to see if you get the same numbers
Just ran it now. Post-alignment, sequential reads now consistently score around 338 MB/s every time I test.

Pre-alignment, sequential reads consistently scored around 353 MB/s (the rated speed of the drive is 355 MB/s)
 

af22

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Just ran it now. Post-alignment, sequential reads now consistently score around 338 MB/s every time I test.

Pre-alignment, sequential reads consistently scored around 353 MB/s (the rated speed of the drive is 355 MB/s)

When you realigned your drive, you essentially shifted every piece of data over. That is gonna be at least 40 gigs of write. How did you realign your drive?

I typically backup it up, sanity erase the entire drive, and restore it fresh.
 

Unknown-One

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When you realigned your drive, you essentially shifted every piece of data over. That is gonna be at least 40 gigs of write. How did you realign your drive?

I typically backup it up, sanity erase the entire drive, and restore it fresh.
I used exactly the same tool as the OP, Paragon Alignment Tool 3.0. The OP saw his sequential read speeds improve after using the tool, so I doubt it's the issue.

I went ahead and forced Windows to TRIM the empty space on the drive (just in case the alignment tool didn't bother with TRIM), and that bumped sequential writes up from 60 MB/s to 72 MB/s (rated sequential write speed of this drive is 75 MB/s). Sequential reads were unaffected, and scored 338 MB/s again.
 
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