[Reduce CPU usage! Very heavy on computation. Algorithm inefficiency?]

Windows' built-in defragger tends to not produce good results when dealing with mechanical drives mostly filled with multiGB files. And refuses to defrag an SSD.

[Reduce CPU usage! Very heavy on computation. Algorithm inefficiency?]

Very small effect on the life of the SSD. I do it only a few times a year. Reduces CPU overhead when accessing fragmented files. And performing this eliminates I/O bottleneck for this experiment so it is clear the process is CPU constrained.

Ridiculous CPU usage when defragging mechanical drives as well.

[Reduce CPU usage! Very heavy on computation. Algorithm inefficiency?]

Thanks for the reply! 3 years later, I am running Defraggler 2.21.993 64-bit on Windows 8.1 on the same machine in the OP. This time on my 250GB SSD. 13% fragmentation. Started it about 4 hours ago. Over 3 hours of 1 core CPU usage now, 29% done on a complete defrag cycle (not quick). Over 350MB of RAM used.

Very CPU constrained. If this was running on a new Intel Ice Lake (10th gen) or AMD Ryzen 2 CPU at 5GHZ I would guesstimate it would be about 4x faster but would still be CPU bottlenecked some times. 

I did just now stop the defrag and select around the top 25 most fragmented files and it successfully completed that in about 15 minutes. Now I am doing a Full defrag (12% fragmented) again. I'll edit or reply again when it finishes.

Is there a way to utilize SSE instructions to optimize the computation?

 

EDIT: First impressions, still going to take 'forever' to complete.

EDIT: Took about 5-6 hours to complete with 3+ hours of CPU time in task manager.

 

 

[Parallel defragmenting?]

I would like this feature as well. Why not.

[Reduce CPU usage! Very heavy on computation. Algorithm inefficiency?]

Hello,

I have used Defraggler off and on for years. I have version 2.17 or so but I doubt 2.2 is any different. The CPU utilization is huge. Monstrous. In comparison to the Windows 7+ built in defragger. 

Often it uses a full core of my CPU, a 3.45GHZ Core 2 Duo in order to defrag a 2TB bittorrent / storage drive. In other words, the algorithms used cannot keep up with the IO constraints of a laptop storage drive (Samsung M9T). 

Also when analyzing, the CPU is often the bottleneck. 

I have notice a lot of aftermarket defrag/optimization programs are very CPU heavy. It is quite obnoxious and should be a priority. But since you are not the only ones, I think O&O used to (haven't test the later versions) have this issue too, and I know Ultimat Defrag is CPU heavy, though the optimization techniques are more complex (sorting by name).

 

Please try to reduce it. It'll save time and power.