cpu power encoding speed/quality

[Z!ppo]

I was reading the xvid faq when I noticed this :


B3. Any hardware recommendations for encoding?

Yes. Get a fast machine. How fast? As fast as your money can buy. Easy eh? Encoding speed depends on raw CPU power, CPU-to-Memory busspeed, Memory speed, and Harddisk speed, in that particular order. You can have a fancy Graphics card that cost you $500 but it won't help you encode one bit faster.
Concerning other parts of your machine, it should be noted that every extra component requires at least some CPU power, even if it's not used. Especially sound and network cards (including 'on-board' ones) can depend heavily on the CPU to do much of their processing. And while Creative soundcards tend to have a lower CPU usage, there are many other reasons not to use them. Another thing is historical: XviD tends to be slightly more optimized for AMD CPU's than for Intel CPU's. But that can change any time.

ok, so you need as many cpu power as possible, but does that improve encoding speed or quality ?

[foxyshadis]

I'd expect speed increases would be obvious. Quality increases won't happen, but what you do get is the ability to turn on higher quality options at less speed penalty, ie, highest quality finishes as quickly as low quality did on your old machine.

[HardwareGeek]

A bigger, badder CPU can execute more instructions in a given period of time. Similarly, it can execute the same number of instructions in a shorter time period. Hence the faster the CPU, the faster the encoding.

As foxyshadis remarks, the final result (i.e. quality) should be the same. Encoding should only take longer with a wimpy central processor.

As the passage that you quoted noted, encoding tends to be more CPU-intensive than anything else. So by adding more memory, you probably will not improve your encoding times by much, but by upgrading your CPU you probably will.

The link below shows a CPU being hammered to 95% of its potential, while encoding. You'll notice, tho', that the memory is not maxed out and probably has more to do with the large number of programs that are open.

http://askaboutcomputers.com/cpu_usage.gif

[Z!ppo]

Ok, Thanks for the nice answers :thanks:
I understand now :p