Why so many ups and downs in speed transfer from SSD to HDD

Started 5 months ago | Questions
Nas from the Valley Regular Member • Posts: 133
Why so many ups and downs in speed transfer from SSD to HDD

Hi all, I was moving some RAW+JPG images from internal SSD to internal HDD (7200 RPM) while noticed that there were so many ups and downs in sthe speed transfer rate (from 170 MB/s to 10 MB/s), it was very anoying and slow. What could possibly be the problem or is it normal? I am not sure but I think I didn't have such issue with the speed transfer few weeks ago when I did the same operation.

ANSWER:
This question has not been answered yet.
bmoag Senior Member • Posts: 2,971
Re: Why so many ups and downs in speed transfer from SSD to HDD

Normal.

The drive heads have to find the place to write to which is often not contiguous. There could also be issues with over-filling the buffer in the hard drive. Hard drive writes tend to top out at 150 bit per second while the read times off the SSD are up to ten times that speed.

 bmoag's gear list:bmoag's gear list
Nikon D70 Nikon D3300 Panasonic Lumix DMC-GX8 Nikon Z6
Robert Zanatta Senior Member • Posts: 2,153
Re: Why so many ups and downs in speed transfer from SSD to HDD

Do you have write caching or write-through enabled on the hard drive?  If not, turning it on might help.

 Robert Zanatta's gear list:Robert Zanatta's gear list
Canon EOS 5D Mark IV
tkbslc Forum Pro • Posts: 16,658
Re: Why so many ups and downs in speed transfer from SSD to HDD
1

bmoag wrote:

Normal.

The drive heads have to find the place to write to which is often not contiguous. There could also be issues with over-filling the buffer in the hard drive. Hard drive writes tend to top out at 150 bit per second while the read times off the SSD are up to ten times that speed.

It is not normal for a healthy hard drive.   When I copy from HDD to HDD or SSD to HDD, I get a steady 140MB+ with only +/-10% variance.    Just tried it again to confirm.   OP is dropping down to 10MB/s with short bursts to normal speeds.  That's not normal.

The only time I've seen this is if Virus Scan is getting in the way, or you have compression enabled, or your hard drive is nearly full.   Fragmentation is only an issue for writes on a full hard drive.  If there is contiguous space, it will not try to fill in fragments.

Sean Nelson
Sean Nelson Forum Pro • Posts: 14,861
Re: Why so many ups and downs in speed transfer from SSD to HDD
1

tkbslc wrote:

bmoag wrote:

Normal.

It is not normal for a healthy hard drive. When I copy from HDD to HDD or SSD to HDD, I get a steady 140MB+ with only +/-10% variance.

Yeah, I've never seen a pattern like that either - but the variation in speed is very regular and it really doesn't look like something I'd expect to see with a fragmented drive.

I'm wondering if it's an SMR (Shingled Magnetic Recording) drive.  Those kinds of drives need to rewrite a set of cylinders on the disk all at once, so the drive might accept a bunch of data into its cache and then wait while it writes that data one of it's shingled regions.

I've never used an SMR drive myself, but it seems like a possibility to me.

NickZ2016 Senior Member • Posts: 2,757
Re: Why so many ups and downs in speed transfer from SSD to HDD

To me that looks like the OS is sending out some files. Waiting. Sending some more. The question is why is it waiting?

Maybe open task manager and look at both drives.

What are the speeds with one large file versus a folder of smaller ones?

 NickZ2016's gear list:NickZ2016's gear list
Nikon D800 Nikon AF-S Nikkor 50mm F1.4G Nikon AF Nikkor 35mm f/2D Nikon AF-S Nikkor 50mm F1.8G Nikon 85mm F1.8G +4 more
Tom_N Forum Pro • Posts: 19,168
Re: Why so many ups and downs in speed transfer from SSD to HDD
2

Sean Nelson wrote:

I'm wondering if it's an SMR (Shingled Magnetic Recording) drive. Those kinds of drives need to rewrite a set of cylinders on the disk all at once, so the drive might accept a bunch of data into its cache and then wait while it writes that data one of it's shingled regions.

SMR = Bringing the rewrite penalty disadvantages of flash / SSDs to hard drives.

I've never used an SMR drive myself, but it seems like a possibility to me.

toomanycanons Forum Pro • Posts: 13,613
Re: Why so many ups and downs in speed transfer from SSD to HDD

Normal.  That kind of pattern can happen with any of my three desktops with any combination of SSD/HD transfer.  Or HD/SSD transfer.  Where I've found I can do something about it is when I finally chose to only plug in external SSD or hard drives in a USB dock to the 3.2 ports in the back of my computers.  The higher power (or whatever) using those ports seemed to smooth things out.

tkbslc Forum Pro • Posts: 16,658
Re: Why so many ups and downs in speed transfer from SSD to HDD

If it was normal for me, I’d throw all my drives away and start over!

sludge21017
sludge21017 Senior Member • Posts: 2,966
Re: Why so many ups and downs in speed transfer from SSD to HDD

Many small files do this.

If you copy a 30GB video file, it will be fast.

Jeff Wahaus Contributing Member • Posts: 576
Re: Why so many ups and downs in speed transfer from SSD to HDD

Nas from the Valley wrote:

Hi all, I was moving some RAW+JPG images from internal SSD to internal HDD (7200 RPM) while noticed that there were so many ups and downs in sthe speed transfer rate (from 170 MB/s to 10 MB/s), it was very anoying and slow. What could possibly be the problem or is it normal? I am not sure but I think I didn't have such issue with the speed transfer few weeks ago when I did the same operation.

Open Resource Monitor and see if anything else is using either HDD when you're doing the copy.  Windows 10 has a really bad habit of scanning your drives every time you boot up.

I just installed a WD Gold 6TB 7200 RPM 256MB-cache HDD and I get a consistent 150-200MB/Sec write speed to this drive when coping from SSD.  (as long as the files are fairly large like 10-20MB image files)

 Jeff Wahaus's gear list:Jeff Wahaus's gear list
Olympus E-M1 III Olympus OM-D E-M10 IV Olympus Zuiko Digital ED 12-60mm 1:2.8-4.0 SWD Olympus Zuiko Digital ED 70-300mm 1:4.0-5.6 Olympus Zuiko Digital ED 50-200mm 1:2.8-3.5 SWD +11 more
toomanycanons Forum Pro • Posts: 13,613
Re: Why so many ups and downs in speed transfer from SSD to HDD
1

tkbslc wrote:

If it was normal for me, I’d throw all my drives away and start over!

Yeah, well, your workflow isn't my workflow.

Sean Nelson
Sean Nelson Forum Pro • Posts: 14,861
Re: Why so many ups and downs in speed transfer from SSD to HDD

Nas from the Valley wrote:

Hi all, I was moving some RAW+JPG images from internal SSD to internal HDD (7200 RPM) while noticed that there were so many ups and downs in sthe speed transfer rate (from 170 MB/s to 10 MB/s), it was very anoying and slow.

I just noticed your user name - is the drive you're copying to a RAID drive by any chance?   RAID-5 perhaps?

tkbslc Forum Pro • Posts: 16,658
Re: Why so many ups and downs in speed transfer from SSD to HDD

toomanycanons wrote:

tkbslc wrote:

If it was normal for me, I’d throw all my drives away and start over!

Yeah, well, your workflow isn't my workflow.

I can't imagine a workflow where I'd accept defective hardware or interfering software, but keep using them if they work for your needs.

OP Nas from the Valley Regular Member • Posts: 133
Re: Why so many ups and downs in speed transfer from SSD to HDD

Sean Nelson wrote:

I just noticed your user name - is the drive you're copying to a RAID drive by any chance? RAID-5 perhaps?

No actually, it says - Type: Basic (NTFS) in the Disk Management

toomanycanons Forum Pro • Posts: 13,613
Re: Why so many ups and downs in speed transfer from SSD to HDD
1

tkbslc wrote:

toomanycanons wrote:

tkbslc wrote:

If it was normal for me, I’d throw all my drives away and start over!

Yeah, well, your workflow isn't my workflow.

I can't imagine a workflow where I'd accept defective hardware or interfering software, but keep using them if they work for your needs.

I agree, I couldn't imagine that scenario either.  But that's not my scenario.   Defective hardware?  Nope.  Interfering software?  Nope.

OP Nas from the Valley Regular Member • Posts: 133
Re: Why so many ups and downs in speed transfer from SSD to HDD

Thank you all for advices! Today I tried the exact same copying of the same files and it was steady all the way to the end! I don't know what was the issue to be honest I didn't change anything since the other day but maybe as someone suggested there were some heavy background Windows processes running at the same time of copying.

skyglider Veteran Member • Posts: 5,987
Re: Why so many ups and downs in speed transfer from SSD to HDD
2

Nas from the Valley wrote:

Thank you all for advices! Today I tried the exact same copying of the same files and it was steady all the way to the end! I don't know what was the issue to be honest I didn't change anything since the other day but maybe as someone suggested there were some heavy background Windows processes running at the same time of copying.

If you haven't already, consider disabling Windows Search.

How to disable search in windows howtogeek

"Windows search" indexes your drives in the background so will have a direct effect on drive operation. Maybe search was indexing when you had the slow copying but was inactive when copying was steady.

I never want anything running in the background that can affect the use of my PCs at maximum speed. I always disable windows search on my two PCs and on my friend's PCs that I support.

I use the "Agent Ransack" search program that only runs when I open it. I never liked windows search since the time I searched for something I knew was on my hard drive but windows search didn't find it. I installed the "Agent Ransack" search program and it found it.  If the windows search index gets corrupt, then windows searches are not reliable.

Sky

WryCuda Forum Pro • Posts: 10,894
Re: Why so many ups and downs in speed transfer from SSD to HDD

skyglider wrote:

Nas from the Valley wrote:

Thank you all for advices! Today I tried the exact same copying of the same files and it was steady all the way to the end! I don't know what was the issue to be honest I didn't change anything since the other day but maybe as someone suggested there were some heavy background Windows processes running at the same time of copying.

If you haven't already, consider disabling Windows Search.

Generally this doesn't improve copy performance.

Better to use Robocopy, particularly if regularly backing up data folders, when incremental backup can happen in a flash.

 WryCuda's gear list:WryCuda's gear list
Nikon D7100 Sony a6000 Sony a7
Timur Born
Timur Born Veteran Member • Posts: 4,972
Re: Why so many ups and downs in speed transfer from SSD to HDD
  • The higher the number of files and the smaller the files the longer it takes. Try to copy the same files from SDD to SDD (can be same drive) to see how that behaves in comparison.

This is copying only 580 mb of files for a second time (all data already in cache) on a PCIe 3.0 M.2 drive. The drive can sustain over 3000 mb/s for single large files.

  • Windows cache might be disabled for one of the drives.

https://www.tenforums.com/tutorials/21904-enable-disable-disk-write-caching-windows-10-a.html

  • With several GB of data Windows cache could be full every time you see a drop, so it has to catch up and wait for former writes to be finished.
  • The HDD could be fragmented, albeit that would usually not lead to such periodic waves.
-- hide signature --

Red flash eyes save lives and eye-sight!
http://en.wikipedia.org/wiki/Retinoblastoma

 Timur Born's gear list:Timur Born's gear list
Panasonic Lumix DMC-LF1 Olympus OM-D E-M5 Nikon D750 Nikon AF-S Nikkor 50mm F1.4G Olympus M.Zuiko Digital 45mm F1.8 +3 more
Keyboard shortcuts:
FForum MMy threads