Half CPU usage about waifu2x-caffe

[lltcggie]

CPUの使用率が約50%に見えるのは表示だけで、実際の使用率は約100%近くだと思います。

CaffeやOpenBLASの内部を詳しく見たわけではないので推測ですが、計算の並列化は論理コア数ではなく物理コア数に対応するように行っていると思われます。（Hyper Threadingを有効にすると計算速度が遅くなるらしいので）
Core i7-4770Kは物理コア数4、 論理コア数8なので、プログラム実行時に「リソース　モニター」で各CPUの使用率を見ると、4つのCPUの使用率が約100%、残り4つのCPUの使用率が約0%になっていると思います。(プログラムのCPU使用率はこれらの平均の約50%と表示される)

[ffleader1]

I think Task Manager read the CPU usage correctly. When running 1x Waifu x2, I was able to do various task easily, and the fan is not loud, due to 50% CPU not being used. Also, I was able to get CPU usage to 75% by running 2x Waifu x2 at the same time. 😄 Anyway, nice program. Much better in upscaling than Photoshop. 👍

[lltcggie]

すいません、CPUを使い切れていないのはCaffeの仕様か、僕の使い方が悪いせいのようですね…
現状では仕様ということにしておいてください。

[ffleader1]

Ok. I will provide an update if I can buy an i7 6900k (not even out yet) later :D

[Jadelor]

@ffleader1 it's a hyperthreading quirk. The CPU of your friend doesn't support hyperthreading at all (I checked the specs) so the Windows task manager shows all of his 4 CPU cores in use (100%). On your hyperthreading-capable CPU, however, it doesn't differentiate between the 4 cores and the 4 ht extensions (8 in total) when displaying CPU stats, so it looks like you're only using 50­% whereas the app is probably giving it all it's got.

[ffleader1]

Ok. After using the program for a while, I have some feedback.

1. The %CPU use for *_Hyper Threading *_depends on the number of Window of Waifu x2.

• 1 Wifefu x2 Running: 50% CPU usage
• 2 Wifefu X2 Running at the same time: 75% CPU usage (37.5% each)
• 3 Wifefu X2 Running at the same tine: 87.5% CPU usage (29.2% each)
  So I guess there is a formula to this. Check below.
  And I think this is not a mistake in reading, because the render time is effected. Rendering 3 image using 1 Waifu x2 would be slower than rendering 3 images using 3 Waifu x2, with 1 each.

2. The program works well with common resolution image like 480p, 720p, 1080p; however, for big images, it seems to keep to lots of artificial detail. Denoise still leaves artifact and Magnify is not very sharp, compared to upscaling from lower resolution.
   So if I have a 4K image:

• If I Denoise it, I get picture A.
• If I downscale it 3 times to 720p, then Magnify 3 times and Denoise it, I get picture B.
  Picture B looks much better than A.
  Weird...Cool, but weird :D 👍

Formula:

Pic A:

Pic B:

[YukiSakuma]

^Looks good I might try your method of upscaling then downscaling and then upscaling again to look better but you said that the sharpness decreases as you upscale so what I do is go increase the (upscaled image) sharpness in Photoshop btw what constants are you using to downscale an image in waifu2x? like 4k to 1080p?