Process multiple volumes at once, switch visibility

[Thaliur]

Hi Jeroen,
I know this might be a bit early to ask for this, but since I installed Windows 7, one of my most favourite new functions in it was the ability to silently (invisibly) defragment all hard disks at once, using the internal defragmentation program.
I know MyDefrag can run silently when using "WindowSize(invisible)", but would it also be possible to process all volumes the current script applies to at once, like with the windows defragmenter? I guess that might save a lot of time, although it would require more memory and CPU time.

Also, is it possible to implement a way to switch between invisible and visible during runtime, again, like in Windows 7 defragmenter?

[jonib]

but would it also be possible to process all volumes the current script applies to at once, like with the windows defragmenter? I guess that might save a lot of time, although it would require more memory and CPU time.

You can run several MyDefrags at the same time to defrag different disks, by changing the OtherInstances setting to allow. But it will use more memory and you need to make sure to defrag different harddisks and not just different volumes.

Also, is it possible to implement a way to switch between invisible and visible during runtime, again, like in Windows 7 defragmenter?

If you want this now my MyDefrag Tray Tools has a function to (un)hide the MyDefrag window, jeroen has it on the wishlist for MyDefrag.

jonib

[jeroen]

Also, is it possible to implement a way to switch between invisible and visible during runtime, again, like in Windows 7 defragmenter?

Use the WindowSize(minimized) setting. The program will then minimize itself to the task bar, and you can maximize it at will.

[Thaliur]

Also, is it possible to implement a way to switch between invisible and visible during runtime, again, like in Windows 7 defragmenter?

Use the WindowSize(minimized) setting. The program will then minimize itself to the task bar, and you can maximize it at will.

That's what I've been doing so far. I will keep on doing that then, it's no problem.
And thanks to jonib, too, I didn't dare try that because I thought MyDefrag required sequential processing.

[jonib]

And thanks to jonib, too, I didn't dare try that because I thought MyDefrag required sequential processing.

As far as I know MyDefrag does not require sequential processing it's just the default, as defragmenting multiple disks puts more strain to the hardware resources, increasing harddisk and CPU temperature and of course uses more memory. I have defragmented 4 harddisks at the same time with MyDefrag without problems, I do have a quad core processor that might help.

jonib

[Kasuha]

defragmenting multiple disks puts more strain to the hardware resources, increasing harddisk and CPU temperature and of course uses more memory.

I'd not recommend to try to defragment two partitions of the same disk at once, but defragmenting two different physical disks at once using two instances of MyDefrag should be OK as long as you have enough system memory.

If CPU or disk temperature seems to be a problem I recommend to consider adding some better cooling to your PC as it might overheat during normal usage too.

[jeroen]

defragmenting two different physical disks at once using two instances of MyDefrag should be OK

Also the two disks should be on different controllers. Most PC's have only a single controller to which all disks are connected, and these controllers will process only 1 disk command at a time. Net result is zero speed gain, but the multiple MyDefrag instances will still eat a lot of memory.

[jonib]

Also the two disks should be on different controllers. Most PC's have only a single controller to which all disks are connected, and these controllers will process only 1 disk command at a time. Net result is zero speed gain

I'm wondering if this is still the case with SATA HDDs? I had 4 disks connected to one SATA controller on my mainboard and defragging all 4 at the same time and all seemed to to be defragged full speed and was done much faster.

jonib

[jeroen]

I'm wondering if this is still the case with SATA HDDs?

Yes. But if your mainboard has a special SATA raid controller chip then chances are it contains a separate controller per disk. There can still be issues with bus bandwidth and things like that.

[Kasuha]

defragmenting two different physical disks at once using two instances of MyDefrag should be OK

Also the two disks should be on different controllers. Most PC's have only a single controller to which all disks are connected, and these controllers will process only 1 disk command at a time. Net result is zero speed gain, but the multiple MyDefrag instances will still eat a lot of memory.

I don't agree with that. Yes, the speed gain is lower than with two controllers, but you don't lose time on head seeks and while one disk is communicating, the other disk can be emptying its cache and the other instance of MyDefrag can use CPU to calculate, so you still gain some speed compared to processing these disks sequentially.

[poutnik]

I'm wondering if this is still the case with SATA HDDs?

Yes. But if your mainboard has a special SATA raid controller chip then chances are it contains a separate controller per disk. There can still be issues with bus bandwidth and things like that.

I think disk bus communication speed, even with the single controller,
is much higher, than physical data read write into/from disk. 
The bottleneck is Disk cache <-> Disk plate transfer.

Maximum steady data transfer for my SATA II seems to be about 80 MB/s, i.e. 640Mb/s.
SATA II bus speed allows 3 Gb/s, effective data throuput to be said about 300 MB/s.

According to small files and disk head movings, real data transfer demand is much lower.
Such 80 MB/s steady data transfer speed goes down
to about 30MB/s for multiple 512kB files transfer,
and to 0.3-0.4 MB/s for 4kB filesizes. ( all speed benchmark measured )

BTW, that seems to confirm my ideas
about 512kB border of file access vs file transfer bottleneck.

[Thaliur]

I just ran two defragmentations, once using windows defragger, once using MyDefrag, and I, too, would not recommend defragmenting multiple volumes with MyDefrag.
Windows defragger can get it done using little resources because it - more or less - only defragments and does little or no optimization, while MyDefrag uses a lot of memory and CPU time to execute all its advanced functions like sorting and zone defragmentation. At least that's what I think.
It might be something that can be run while the computer is absolutely not in use for some time, maybe combined with a .bat file that automatically shuts down the computer when both defragmentations are done (I wouldn't trust the "WhenFinished(shutdown)" command in this case, because you can never be sure which defragmentation ends first).