Why did my 4k write score drop?

[death_samurai]

I ran crystal disk mark and AS SSD benchmark and this was after i had internally erased my ssd and restored it again and updated the firmware to 4.2


Previously i used to score around 70ish in my 4k write score but i now only score around 50ish.

Does anyone know why?

I'm using the gskill phoenix pro 120GB ssd.

[Darren Hodgson]

Is TRIM working correctly? There's an easy way to check it from the command prompt (just Google it).

More importantly, does SSD seem noticeably slower in general use? If not then I really wouldn't worry about the results from artificial benchmarks.

[death_samurai]

yes trim is enabled.

[Virtue]

Make sure your drive is also properly aligned. Follow this to be sure about everything http://www.overclock.net/t/1156654/s...-for-ssds-hdds

but other than that you should probably ask this on the gskill forum

[IcE]

Originally Posted by Darren Hodgson

Is TRIM working correctly? There's an easy way to check it from the command prompt (just Google it).

More importantly, does SSD seem noticeably slower in general use? If not then I really wouldn't worry about the results from artificial benchmarks.

TRIM isn't used on Sandforce, just garbage collection. So whether it's enabled or not is irrelevant.


As for the reason behind the drop, could be a ton of things. 4K performance IIRC goes down when there's less free space/freespace fragmentation.

[Agent-A01]

Originally Posted by ice445

TRIM isn't used on Sandforce, just garbage collection. So whether it's enabled or not is irrelevant.


As for the reason behind the drop, could be a ton of things. 4K performance IIRC goes down when there's less free space/freespace fragmentation.

Trim is used when all the drive's nand is not fresh.

OP let your pc sit in the bios after you do a clean. ie ccleaner/disk cleanup for an hour or two. my gskill needed it after a while. speed it up nicely because GC never does work for me while im in the OS. i only notice a difference if i let it do it in bios.

[death_samurai]

to agent how do u let ccleaner do it in the bios? I only know how to operate it on windows.

[Agent-A01]

lol no i didnt mean do it in bios. i meant let it clean up some space in windows, delete your old restore points, and empty out the windows/softwaredistribution/downloads folder. i also would do this batch file that clears out all logs in event viewer(in a old os ive seen it stack up to hundreds of MB, they are useless logs). http://forums.windowsforum.org/index...howtopic=46107

after all that, let your system idle in the bios for an hour or two and let garbage collection do its work.

[death_samurai]

my installation is kind of new i suppose. I don't have restore pts. I use 3rd party ghost software to backup and then restore.

[scheherazade]

4K @ what queue depth?

qd0 shouldn't be affected by anything... as IIRC it generally only writes to one chip at a time - so load-balancing is a non-issue.

-scheherazade

[Agent-A01]

Originally Posted by death_samurai

my installation is kind of new i suppose. I don't have restore pts. I use 3rd party ghost software to backup and then restore.

doing ghost is bad.. causes mis alignment of the os on the drive causing reduced performance..

[IcE]

Originally Posted by Agent-A01

doing ghost is bad.. causes mis alignment of the os on the drive causing reduced performance..

Not if it's aligned when you ghost it. Source for this?

[PhazeDelta1]

Originally Posted by Agent-A01

doing ghost is bad.. causes mis alignment of the os on the drive causing reduced performance..

If you align it before hand, your fine. If you use Clonezilla or Windows Image, those 2 programs will copy the alignment to the new drive automatically.

[Agent-A01]

Originally Posted by ice445

Not if it's aligned when you ghost it. Source for this?

First hand Experience. had a bunch of dell 760s at a place i did some work, so i decided to do one OS and copy all the drives. one publisher wanted it as fast as it could so i put in an agility 3 from ghost copy and it was acting kinda slow. so i checked the alignment of the drive, and it wasnt aligned. reinstalled and it fixed the speed. If you need hard evidence, use google.

Also, SSD nand have 512kb block sizes and by defualt windows 7 uses 4096kb cluster sizes(which is fine for regular drives) if its set higher than 512kb the SSDs have to atleast double their writes which reduces lifespan overtime and loses write performance.

[death_samurai]

Guys i'm using acronis which i read is one of the best to create image of your HDD. My HDD is partitioned into 2 drives. How do i check if it's misaligned?

[death_samurai]

Guys i have paragon alignment partion tool cos once i had to change the size of one my drives and i used it to correctly align the drive. That was done months ago. I ran it today again and it says my SSD drives are perfectly ok so i suppose it's not the alignment that's causing the drop in 4k.

[IcE]

Originally Posted by Agent-A01

First hand Experience. had a bunch of dell 760s at a place i did some work, so i decided to do one OS and copy all the drives. one publisher wanted it as fast as it could so i put in an agility 3 from ghost copy and it was acting kinda slow. so i checked the alignment of the drive, and it wasnt aligned. reinstalled and it fixed the speed. If you need hard evidence, use google.

Also, SSD nand have 512kb block sizes and by defualt windows 7 uses 4096kb cluster sizes(which is fine for regular drives) if its set higher than 512kb the SSDs have to atleast double their writes which reduces lifespan overtime and loses write performance.

I'm going to test this myself with Windows Backup and see what I find. As for your second point, there's no need whatsoever to change the cluster size from the default 4096 BYTES (Not Kilobytes). 4KB is the optimal balance between available space and file system performance with ANY modern drive.
Check them units dawg, they matter.

[IcE]

I just tested the first point and it turns out that if you use Windows built in system image creator, it preserves alignment after a restore. I can't speak for other utilities, but the built in one definitely works. Also I accidentally hit quote instead of edit...

[---TK---]

did you just quote yourself? lol edit fixed

[Agent-A01]

Originally Posted by ice445

I'm going to test this myself with Windows Backup and see what I find. As for your second point, there's no need whatsoever to change the cluster size from the default 4096 BYTES (Not Kilobytes). 4KB is the optimal balance between available space and file system performance with ANY modern drive.
Check them units dawg, they matter.

Yes there is a point. If its not 512bytes then there will have to be multiple writes across several blocks of data when there should only be one write because 4096 will not fit inside the nands 512byte block size. which =s reduced nand lifespan and performance

Also not exactly why i said kb lol. must have been tired or something
Btw, i am talking from first hand experience, ive had a total of 7 SSD drives. Done lots of tests and 512bytes is by far the optimal cluster size. Write speed is reduced by half for me when using 4k cluster size. For my main OS drive(2 agility 3s) i hit 1200mb/s sequential read and 1000~ write using 256 cluster size. by default windows 4k my write was not even hitting 600mb/s. same story for my 2nd raid array for games, significantly reduced write speeds.

[scheherazade]

Writing larger blocks than SSD block will not cause extra writes.

Writing SMALLER blocks than SSD block will cause extra writes.


eg.

if SSD block size is 512, and you write 4096 data as one 1 4096 chunk, then you write 8 complete 512 block.
OK

if SSD block size is 4096, and you write 4096 data as 8 512 chunks, then you write 8 complete 4096 block(smallest write = block size, so 512 becomes 4096).
32768 written in total, for only 4096 data, BAD

You want :
1) your file system's blocks to be aligned with SSD blocks,
2) file system's blocks are whole multiples of SSD blocks (preferably increasing in powers of two).


Drive internal cache will mask a lot of this, since what you write isn't written all at once anyways, but a moment later. So a bunch of wasteful writes are conglomerated into a few less wasteful writes.





All that said, for example, the Crucial M4 uses 4k blocks) for 64gig/128gig, and 8k blocks for 256gig/512gig.
(although I may be mis-remembering, and it could be 64/128/256gig=4k, and 512+gig=8k)

Although the interface still exposes the M4s as having [virtual] 512 blocks, to be maximally compatible (since the new "advanced format" 4k exposed drives are less compatible with older bios').

-scheherazade

[IcE]

I was under the impression that block sizes were 512KB and not 512 bytes from the casual googling I did.

[Darren Hodgson]

Originally Posted by death_samurai

Guys i'm using acronis which i read is one of the best to create image of your HDD. My HDD is partitioned into 2 drives. How do i check if it's misaligned?

AS SSD Benchmark will show the offset in green with a polite 'OK' if the alignment is correct so try that.

http://alex-is.de/PHP/fusion/downloads.php?cat_id=4

[scheherazade]

Originally Posted by ice445

I was under the impression that block sizes were 512KB and not 512 bytes from the casual googling I did.

Yes. recent SSDs are 4096 bytes (4k) (and some are 8192 (8k)).

-scheherazade

[Agent-A01]

Originally Posted by scheherazade

Yes. recent SSDs are 4096 bytes (4k) (and some are 8192 (8k)).

-scheherazade

like what? all sandforce drives use 512bytes, the new indilix based drive from ocz uses 512bytes, the samsung 830s use 512bytes.. those are the only recent ones i can think of.