Problem:
Using DOpus to copy files from Win7 box to/from a Windows Home Server (WHS) share is slow (~30 MB/s). Switching to Windows File Explorer for the same copy, the performance jumps to 85-95 MB/s. My test case file is ~3 GB, large enough for repeatable results. For reference, between 2 Win7 computers I can sustain 110 MB/s with Windows File Explorer.
Background:
I have a number of computers attached to a gigabit switch including multiple Win7 boxes and a Windows Home Server (WHS). I only use DOpus on 2 of my computers. I've been trying to track down a file copy performance issue. I am regularly moving files that are 0.5 to 8 GB in size to/from my WHS box. In the process of trying to determine the performance issue I stumbled on the solution (don't use DOpus) when I was testing combinations of source/destinations between all my computers for moving large files.
I've played with Jumbo Ethernet frames (FAIL for my mix of equipment), changing settings in Win7 related to network (IPV6 turned off, disabled "Remote Differential Compression", toggled TCP/IP window auto-tuning), and other potential issues. I do expect my WHS network performance to be a bit lower because I had to use a PCI gigabit ethernet card instead of the onboard gigabit port (driver issures) and that is matched by Win7->WHS being ~15% slower.
I'm pretty confident the issue is DOpus. The question is why is DOpus so much slower than native Windows File Explorer? I much prefer to stay in DOpus but going from 30MB/s to 90 MB/s is a HUGE improvement for NOT using DOpus.
The performance problem is happening on both of the Win7-64 machines that have DOpus installed with very little hardware in common (one is an old Core2 Quad Q9550 and the other is an Core i7-875k). Even my dual-core atom box hits >110MB/s on file transfers if I avoid DOpus.
[ul][li]See if increasing the copy buffer size helps. (Settings -> Preferences -> File Operations -> Copying Files.) You should cancel any file transfers before changing it, then start new ones after changing it.
Try setting it to 640 KB, for example. (The default is 64 KB.)
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[li]What speeds do you get in other tools? e.g. Copying from a command prompt, or using TeraCopy?
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[li]Is the same anti-virus tool used on both Win7 computers? If so it may be worth disabling it in case it is involved, e.g. because it inspects Opus's file or network access differently to Explorer's. (Although, unfortunately, disabling some a/v tools doesn't properly disable them and only uninstalling them does... But that's only worth trying if nothing else seems to help.)
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[li]Make sure you don't have anything active in Opus which would cause Opus to open the files to display information. For example, the Description column or thumbnails. If Opus is trying to get information out of files it could be slowing things down, especially if something is going wrong in the process. For example, some buggy video codecs can go into an endless loop when Opus asks them to provide information on an AVI file. Worth ruling out in case it's happening.
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[li]Are file transfers between the two Win7 machines fast? i.e. Does this happen for all network file copies or only ones involving the WHS machine?
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[li]Where are the source files that you are copying from? Are they always local to the computer you are testing from or are they on a network share somewhere? (If Opus is having to read the file over the network, then send it over the network, while Explorer has some way to tell the WHS to fetch the data directly, that might explain the difference.)
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[li]I'm assuming you have timed the file copies using a clock, in case the reported speed in Explorer and/or Opus is incorrect.[/li][/ul]
I have verified that A/V scanner isn't affecting the results.
Your suggestion to increase cache size has definitely helped. I increased it to 8,192 KB since I have oodles of RAM. I jumped from 30MB/s to 70MB/s transferring to WHS share.
Transfers between the Win7 machines are fast if I avoid DOpus. The only combination that is slow is DOpus to any other machine. I mentioned WHS since that is my mega-storage machine with 9 TB of space.
The files are always coming from a local drive.
You raise a valid point about using wall clock time. I will repeat my tests with even larger files and use a stopwatch.
Daroc, I guess someone with more knowledge of the internal of Directory Opus will answer you but something I didn't mention: this computer is used for 3D work and it has 24 GB of memory (dual xeon W3690). Maybe on a more standard computer, something like 512 or 1024 kb would be more appropriate.
I see. I set 256 KB and it seems to be the best option on my notebook with Dual Core and 3 GB of RAM. But there is slight difference between 64 and 256. I just wanted to test something new.
It makes sense. I haven't really noticed a difference in speed when copying from disk to disk (roughly 100 - 110 mb/s with two 2TB Caviar Green, a lot slower when copying from one partition to another on the same disk of course). Roughly the same speed when copying on an external in USB3 and around 20 mb/s in USB2.
The only place where changing the buffer makes a huge difference is over the network. Then the speed is about twice greater with a big buffer (I probably go over the top with 8 mo though )
