Question Can SSDs write 2 different partitions simultaneously?

ThomasHoey

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Hi Forum,

I wonder if anyone can help with my question.

can SSD's write to 2 separate partitions simultaneously?

When the CT is in use it writes its data to the images folder in D partition. The CT is erroring out when there is any extra load on the C partition.

for instance

when I use Heavy load to write a temp file to the C partition wile I run the CT, the CT errors. A full cycle on the CT takes 720 images and when I increase the load on using Heavy load on the drive it fails anything over %49 disk usage.

the higher the usage on the drive the quicker it fails

49% disk usage = 710 of 720 images error
70% disk usage = 650 0f 720 images error
98% disk usage = 620 of 720 images error

When I point Heavy load to save temp file to the D partition (same as CT) everything works fine an no errors occur.

I have a backup running from the C partition that I believe is causing the error.
 

ThomasHoey

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Yes.


That backup may have the files locked. Hence an error.


What is "the CT"?
No files locked on the Backup

CT is Computed Tomography used for xrays

Its not the backup that I'm having issues with but when the drive is over 49% usage I'm getting a failure on the CT as it saves files to the D partition.

I have tested the network between CT and PC for and there is no connection drops or Packet loss.

The error only happens when there is another application writing to the C partition on the drive.

I am just going to rebuild system and have one partition . The point in the two partitions was to keep x-ray images separate
 

kanewolf

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No files locked on the Backup

CT is Computed Tomography used for xrays

Its not the backup that I'm having issues with but when the drive is over 49% usage I'm getting a failure on the CT as it saves files to the D partition.

I have tested the network between CT and PC for and there is no connection drops or Packet loss.

The error only happens when there is another application writing to the C partition on the drive.

I am just going to rebuild system and have one partition . The point in the two partitions was to keep x-ray images separate
Since the CT is effectively streaming the images, if it fills its buffer (the PC is slow) then I would expect it to fail.
Total data written on both partitions is more important.
What is the model and size of the SSD in question ?
Write performance on some SSDs slows after 50% full. For a performance critical situation, you definitely need to keep it below 80% full.
 
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Your plan to change to a single partition is a good one.
A ssd needs to have available nand blocks available to do an update.
When the space approaches full, this becomes more difficult, resulting in lower performance and rapid deterioration of endurance.

You would probably find upgrading to a good performing 1tb ssd a worthwhile thing to do.
What is the make/model of your motherboard?

If your motherboard is pcie m.2 capable, look into the samsung m.2 pcie 980 pro
Or, a pcie adapter may also be an option.
 
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ThomasHoey

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Since the CT is effectively streaming the images, if it fills its buffer (the PC is slow) then I would expect it to fail.
Total data written on both partitions is more important.
What is the model and size of the SSD in question ?
Write performance on some SSDs slows after 50% full. For a performance critical situation, you definitely need to keep it below 80% full.
yes that makes sense, never considered it like streaming but thats exactly what the CT does essentially streams it to a temp folder as individual images then stitches it together into the images folder.

the SSD is a Samsung 850 512GB and it is about 85% percent full.
 

USAFRet

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yes that makes sense, never considered it like streaming but thats exactly what the CT does essentially streams it to a temp folder as individual images then stitches it together into the images folder.

the SSD is a Samsung 850 512GB and it is about 85% percent full.
--------------
C partition has 120GB space
D partition has 65GB
--------------

What is in the rest of the drive?
 

ThomasHoey

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Ah, OK.
I read it the other way around.

" C partition size is 120GB, etc..."


Still, a single partition is best. OS and applications.
And the CT files possibly off on a whole other physical drive.
Yeah this is my thinking.

just strange that when I have the CT running and another application writing to the C partition it fails

but if I have the same application writing to the D partition and the CT running, it works fine with no errors
 

USAFRet

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Yeah this is my thinking.

just strange that when I have the CT running and another application writing to the C partition it fails

but if I have the same application writing to the D partition and the CT running, it works fine with no errors
Thats weird, because 'partitions' on an SSD aren't really physical delineations, like they would be on an HDD.

On an SSD, they are merely logical, visual representations that the OS shows you.
The drive firmware shuffles data around behind the scenes.
You can't point to a particular chip or cell and say "That is in the D partition".

On an HDD, partitions are actually different portions of the platter(s)
 

ThomasHoey

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Thats weird, because 'partitions' on an SSD aren't really physical delineations, like they would be on an HDD.

On an SSD, they are merely logical, visual representations that the OS shows you.
The drive firmware shuffles data around behind the scenes.
You can't point to a particular chip or cell and say "That is in the D partition".

On an HDD, partitions are actually different portions of the platter(s)
so with this in mind then I assume that SSD is in fact just one drive which the OS has theoretically partitioned.

I think what I will do is rebuild the system and add two separate SSD's one for OS and one for the Ct to save its images.
 
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USAFRet

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so with this in mind then I assume that SSD is in fact just one drive which the OS has theoretically partitioned.

I think what I will do is rebuild the system and add two separate SSD's one for OS and one for the Ct to save its images.
Correct.

Windows knows about partitions, allows you to create them, and shows it to you.

But the drives internal firmware controls where the actual data lives.
And a particular byte that is here today may be in some other physical location tomorrow.


And your plan for the drives is a good one.
 

ThomasHoey

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Correct.

Windows knows about partitions, allows you to create them, and shows it to you.

But the drives internal firmware controls where the actual data lives.
And a particular byte that is here today may be in some other physical location tomorrow.


And your plan for the drives is a good one.
Yeah that makes sense.

Does that also mean there is no need to de-fragment an SSD as it will keep everything optimized?

I have to do some research on SSDs and their differences
 

kanewolf

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Yeah that makes sense.

Does that also mean there is no need to de-fragment an SSD as it will keep everything optimized?

I have to do some research on SSDs and their differences
DO NOT defragment an SSD. Many tools recognize SSDs and won't even allow it. The write leveling alg on the SSD puts data where it is best. Let it do what it wants to.
 

USAFRet

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Yeah that makes sense.

Does that also mean there is no need to de-fragment an SSD as it will keep everything optimized?

I have to do some research on SSDs and their differences
As above, do NOT defrag an SSD.
Serves no purpose other than to create additional write cycles on the drive.

Windows knows the difference, and treats SSDs accordingly.

As long as TRIM is enabled (it is by default), you need do no manual maintenance like that.
 

ThomasHoey

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As above, do NOT defrag an SSD.
Serves no purpose other than to create additional write cycles on the drive.

Windows knows the difference, and treats SSDs accordingly.

As long as TRIM is enabled (it is by default), you need do no manual maintenance like that.
No I wasnt planning on doing nor have I ever done a de-fregment on an SSD.

Thanks everyone for there help.
 

TommyTwoTone66

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I think this is software related and is likely an incompatibility with the backup software and the firmware of your SSD. In theory an SSD could be partitioned into 20 different drives and should be able to both read and write to them all simultaneously without any errors. Does the issue still occur with the backup disabled?

You might find updating the firmware on the SSD and / or updating your system BIOS resolves the issue. Then again they might not have addressed this yet updating might do nothing. Going to a solution with two separate drives will surely be a fix in that case.

Updated firmware is available here
 
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hang-the-9

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Set the anti-virus software to not scan the folders for the program and where it writes to. I have had issues with real-time recording of data in computers using medical instruments (before SSD days though) and the issue was the anti-virus. Once I set an exclusion list for the folders the program was using it worked properly.
 

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