Computer Hope
Microsoft => Microsoft Windows => Windows Vista and 7 => Topic started by: cincyshirm61 on September 03, 2013, 06:43:13 PM
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Hi,
I have a Windows 7 64-bit machine with an AMD Phenom II x4 965 processor, ASRock 890GX Pro3 motherboard, 8gigs ram, a 64gig ssd OS drive, and a Storm Scout SGC-2000 case.
Every time I go to transfer a large file (500+mb) to a flash drive (multiple drives ranging from 1gb - 32gb) it will go extremely fast, as expected, until about the last 5%, then it will hang for 2-4 minutes. Is there a reason this is so inaccurate? Should it be going faster? This has been the same even after I reformatted and resinstalled win7.
Any help would be great, thanks in advance!
[recovering disk space, attachment deleted by admin]
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Actually a normal occorence since the file header and end are both written at the end of the process...perfectly normal.
P.S...try TeraCopy if you want to speed things up.
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Completely normal. Your flash drive isn't transferring at 152MB/sec - it's basically caching the write, so you see a high transfer speed as the file is written to cache, then it has to catch up with itself and actually do the write to the drive.
As patio says, Teracopy or other alternatives will copy a little faster than Windows Explorer, but you won't get anything to write faster than your flash drive can manage.
The above should be disregarded if you do actually have a fast USB3 flash drive capable of writing at 152MB/sec, but there aren't many out there.
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Thanks a lot for the quick, accurate responses guys. I assume there is no way to change this to display a more accurate representation of overall time to complete the entire task? I will look into Teracopy, although most likely just live with windows. At least I now know there is nothing wrong with my system!
Thanks again!
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Basically it boils down to Calum's explanation, somewhat. Data from that file already in the file cache will mean that data is read in much faster than if it was to hit the disk.
The Write, however, is more deterministic. Windows Vista was well known for it's wildly inaccurate predictions. Those predictions and problems were a result of the copy being changed to use a write cache; meaning that the operation would go really fast until, as Calum noted, it had to actually start performing the write operations and hitting the disk. People got pissed because when the dialog was gone, data was still being copied in the background.
Windows 7 (and presumably 8) change this, however. Now, the dialog will stay until the copy is completed in it's entirety- thus why the progress bar stops near the end. As far as the User-level software is concerned- the copy has completed. It's done. All the data is transferred. However, in reality, that data is still waiting in The write buffer to actually be written. Win 7 will finish copying everything, But what it does is also acquire a handle to the operation, and then it waits on it. What this means is that it will stick around until the copy is actually finished, and tries to flush write operations.
For the ProgressBar, this is a bit of a tricky thing to represent- there is no way to really know how much of the data is actually transferred to disk and how much is still waiting to be written. So it just sorta sits there, waiting. For the copy to actually complete.
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Thanks for the detailed reply, BC_Programmer. This makes much more sense now!
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Add thanks from me too. This is one of the best threads tees month!