I have an old i7 860 with a very mild over clock. I consider myself a heavy HandBrake user. I have put about 3000 feature films and 4000 documentaries on my NAS in mp4 format from DVDs and Blue Ray disks, all in original quality. I have been trying to learn as much as I can about building a PC for handbrake use, I don't know much but I'd like to share what I think I know and perhaps get a discussion going.
I've been planning a HEDT build for several months now but the delay of Haswell-E and x99 motherboards has given me time to research.
1) in a general way handbrake performs in a linear way with respect to clock speed and number of cores. So the more of either the better.
2) Apple folk report that the improvement is non-linear with threads greater than 9. Again precise details are sketchy.
3) I found this motherboard review
One might note under the table titled "Handbrake v0.9.9 Film CPU Only" that the difference between the 6 core i7-4960x and the 4 core i7-4770k is trivial, less than 1%. That test is at 640x266 not quite DVD quality; where the extra cores just do not help.
in contrast look at the chart labeled "Handbrake v0.9.9 2x4k CPU only" where the resolution was double UHD (3840x4320) where the table indicates that more cores do have at least
a linear effect on encoding speed.
The author provides this enlightening thought: "The reasoning here is simple – when frames are small enough to fit into memory, the algorithm has more chance to apply work between threads and process the video quicker. Results shown are in seconds and time taken to encode."
Now we have two data points with no information in the middle. OK for DVD quality more than 8 cores helps very little. At resolutions double that of 4k more cores do have at least
a linear contribution and all this is also tied into the quantity of memory, goal being to at least one frame in memory at one time.
This could be greatly simplified because I see only a few cases and only one of which is really interesting.
1) Handbrake for less than DVD quality - more than 4 core/ 8 thread is not helpful.
2) DVD quality (720x480) - more than 4 core/ 8 thread is not helpful.
3) Blue-Ray quality - missing data.
4) UHD (3840x2160) - data missing
5) double UHD (3840x4320) - get all the cores you can.
As I encode more and more Blue Ray disks to my NAS more information on case 3) would be very useful. I don't know the future of 4k (UHD) but I know I I do not expect to be using any 4k original content soon so it is not germane to my hardware choices right now.
But the reference "when frames are small enough to fit into memory" has encouraged me to build my next PC with 2x8GB memory, A total of 16GB system memory with empty slots to double system memory to 32GB.
I will cc Ian Cutress, because no other place anywhere on the internet as a information on the relationship between the number of useful cores and resolution, (clock speed being held constant) and perhaps the effect of memory space on different resolutions for handbrake, and I consider handbrake the driving force for HEDT with more than 4 cores on the desktop. What other popular consumer applications multithread as well as HandBrake?
The sub DVD quality case is trivial. What ever most folks have now is ample.
The DVD quality case is interesting mostly as data point, and because most of the video content (at least most of the 7000 videos on my NAS) are DVD quality. As I see it the most popular 4 core CPU manage DVD quality well enough.
Here is where it become very critical to me personalty, should I hold out for a 6/8 cores CPU to encode Blue ray quality content? That is the million dollar question because I see that as the bulk of my work for the next five years.
And I assume with UHD and Double UHD content we all need all the help we can get.
Any more research especially at the blue-ray quality level would be a great service to the PC community.Edited by Eddie Felson - 6/6/14 at 2:58pm