Platter HDD is SLOW, but bursts fast

Z

zzz

Gawd
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Oct 9, 2006
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On a fresh bootup to Windows, if I transfer several MP3s from my SSD to my 640GB WD, the first ~7 files instantly transfer, while the rest take forever, taking maybe 30 seconds per file. And on future attempts, the first file might instantly transfer, while the rest are slow. It used to run way faster.

I just switched the motherboard SATA port it's plugged into, and that seems to have sped it up quite a bit, but it's still dog slow and <1MB/s.

What the heck could be causing this? It's not the boot drive and there's nothing running in the background; CPU usage sits at 0% if you don't do anything. Recent WinXP install, 3GHz C2D, using 0.2GB/2GB.
 
Not sure what you are asking, But wndows caches disk reads and writes. Once the memory buffer gets full, it will only write as fast as the drive can write to the disk itself. So even after explorer comes back and says done, the drive would still be going. Use windows task manager and look at the performance tab and memory used, it will go up and down as files are read and written. I the drive has NCQ it goes much faster. Without NCQ it slows it way down as windows has to update the MFT all the time as well as write the data and it sort of locks itself. SSD's all have NCQ so it dont lock itself like HDD's do. many HD's do have NCQ as well but not all. Try using teracopy without windows cache enabled option. That way you can find out the write speed without NCQ getting in the way of things. Windows itself has no way of doing it as it is a multitasking system. Eg.. From my testing for a drive with NCQ write speeds of 120MB or higher.. Without NCQ that is around 110MB and using windows that speed drops to under 50MB.. I think windows assumes that all drives will come with NCQ. It came out decades ago but "some" companies decided to purposely disable such advanced functions to sell higher priced enterprise drives.
 
Hey thanks for the detailed response. I guess the caching part fooled me into thinking the disk was writing fast. At any rate though, performance is insanely slow at <1MB/s, and it didn't use to be like that. I'm wondering why that is and how to fix it. I did try disabling write caching in Device Manager but it didn't make much difference.
 
Backup important data ASAP and check your SMART values with something like crystaldiskinfo.

Alien's explanation about the cache is correct and points to the media itself being in a very bad state.Also check the windows system log. Now, please ;). Don't experiment any further.
 
Oh are all these a problem? ;) http://s12.postimg.org/xg39d8t31/pic.png

I'm not sure why they're all dated 6/7 though, since I was also doing transfers 6/8 and today. I also noticed that when I run MP3 Tag Studio, which is a batch-processing ID3 writer, it completely hangs on the platter drive and causes the MP3 it ends on to have a file size of zero and destroys that file. I have it backed up of course.

But other everyday operations seem to run ok. I guess maybe the disk is just going bad.

I'll do a new build once Skylake comes out but that's gonna be at least several months!
 
Check the SMART data with CrystalDiskInfo. The drive could to be at the verge to death.
 
but it's just not apparent in software.
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The SMART status are values the drive collects itself. The software is just asking the drive for these attributes and printing them.

Edit:

You have most likely a bad sata cable or connection. Look at the RAW value of C7 Ultra DMA ECC Error Count. This value indicates the # of sata packets that needed to be resent. Normally this should be 0 or a very small number.
 
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This is going to sound ridiculous ... Make sure none of your SATA cables are bent or crimped tightly at 90 degrees or more. I had one drive that wouldnt detect correctly and another SSD that would only transfer at 250 MB/sec. Once I removed the tight bends they both started behaving properly..

Also, any chance your drive is super fragmented and low on space?
 
dre and TGK, you guys know your stuff! I swapped the cable with a new one and transfers are lightning fast. With writing 30 MP3s, the dialog box appears for about 1 second.

I guess the cable just degraded over time. I hadn't touched it in a long time. It does have some bends as you'd expect, but nothing drastic. Each 90 degree turn is done across 1cm. I should change the SSD cable while I'm at it. This was only 3Gbps SATA across a 22" (~0.5m) cable. 6Gbps SATA would be even more sensitive.

I still don't know how to read the Crystal report; they didn't exactly make it the most intuitive. And I'm not sure why my SSD has no "C7 Ultra DMA CRC" category. Is there a way to reset the values so that the Current column goes to default values, while Worst is always static? Why is the Temperature's Worst value lower than Current, and why doesn't the current value change if I reload the program or hit F5?

At any rate thanks!!!
 
Is there a way to reset the values so that the Current column goes to default values, while Worst is always static?
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Not really. This is what the drive reports Crystal Disk Info is just printing a table from the drive itself.


Why is the Temperature's Worst value lower than Current, and why doesn't the current value change if I reload the program or hit F5?
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The current and worst are scaled values where 100% is good and as the numbers go down they indicate a problem. The threshold is the value that if the drive is below that # the drive maker indicates this is a problem.

The raw values are the actual data for most drives. Convert the hexadecimal to a decimal number for the current readings. When I monitor drives ( I have 100 to 200 for 10+ years) I ignore the Current and Worst and look only at the raw.
 
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zzz said:
Now it's back to taking 30 seconds per file!
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Could be the electronics of the hard drive going bad or having a loose connection.

I assume the raw value of C7 Ultra DMA CRC has increased from 000A0969 (which is 657,769)
 
Yeah, now I swapped the motherboard SATA port and also re-inserted the connection to the HDD, and it's fast again now.
 
And now just 10 minutes later, without even rebooting, it's back to being slow. It doesn't appear to be related to the physical connection/continuity.
 
zzz said:
And now just 10 minutes later, without even rebooting, it's back to being slow. It doesn't appear to be related to the physical connection/continuity.
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Have another PC you can try the drives out in? Time to eliminate either the drive or MB as the cause.
 
Also make sure that there isnt anything else hitting the drives; in performance monitor you can view the overall reads and writes being directed toward the drives. Could be antivirus trying to scan and causing contention.
 
Sorry for the delay. Yes, C7 now has a raw value of A16B9.

TGK, since my SSD works fine, and I've tried 2 motherboard ports on the HDD, it seems it's most likely the HDD with the problem. There's definitely no other software trying to write to the HDD and I don't use antivirus.
 
zzz said:
Sorry for the delay. Yes, C7 now has a raw value of A16B9.

TGK, since my SSD works fine, and I've tried 2 motherboard ports on the HDD, it seems it's most likely the HDD with the problem. There's definitely no other software trying to write to the HDD and I don't use antivirus.
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Last step to try is plugging the data cable connected to the ssd into the hard drive. Don't change the port or cable. If the DMA errors continue time to RMA the drive.
 
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