Encoding PC - which CPU

[duffbeer]

I have an i7 3770k system which is now 7 years old and starting to show it's age. It's becoming a little flakey and too slow to encode UHD files with x265.
I am considering a 9700k or a 9900k. I don't mind the extra cost providing the encoding speed benefit is decent.
I believe my 3770k has lasted this long because I spent good money at the time and bought good components to go with the top of the range i7.

During my research I have not found any relevant information comparing the 3770k to the 9700k/9900k. I assume this is because the age gap is so large! Most reviews seem to be talking gaming performance which is not what I need to know.

I have a couple of questions about the latest Intel CPUs:

1. I'm hoping that either if the new CPUs would at least double my encoding speed. Does that sound realistic?
2. I've read that too many threads can degrade image quality. Is 16 threads on the 9900k too many?
3. I really want to know about any real world comparisons between the 9700k and the 9900k with regard to x264 and x265 encoding. Is the difference noticeable?

Thanks in advance for any advice - I really need it!

 

[Alexrose1uk]

If this is anything to go buy, there are decent gains to be had in encoding! Either AMD or Intel will do you well here:
https://www.anandtech.com/show/13400/intel-9th-gen-core-i9-9900k-i7-9700k-i5-9600k-review/8

Look at the 6700k for an idea, that is essentially a slightly faster per clock, higher clocked version of your chip; it still features the same 4c8th and similar core design to your current chip.

Now...judging by HERE:
https://www.anandtech.com/show/9483/intel-skylake-review-6700k-6600k-ddr4-ddr3-ipc-6th-generation/11
(X264 benchmark) the 6700k is about 30% faster than your 3770K, so if you then extrapolate that to the first link...

If you are drawing the same conclusions as me, twice as fast maybe even a bit more seems possible!

The AMD Chips are not as strong here at Intel, but also worth considering given the value proposition with the upcoming Zen 3000 (Zen 2 release) and rumoured performance per core and core count improvements (and if you bought a 2600 now, and a decent motherboard, you should be able to throw a Zen 3000 into the same motherboard with a firmware update)

 

[duffbeer]

Thanks for posting. Sounds like my guess at the speed increase may be about right.
I can't convince myself to go down the AMD route. If I was gaming it would be a good choice but for video encoding I think the Intel is a better option as they have higher clock speeds and less threads.
Any idea about the image quality? I'm not sure if I would be better off with a 9700k as that doesn't have HT.

 

[z10m]

I can't convince myself to go down the AMD route. If I was gaming it would be a good choice but for video encoding I think the Intel is a better option as they have higher clock speeds and less threads.
.

not sure about the quality degradation with more threads but usually it's the other way around.
For gaming you are better off with less threads and higher clocks and for video encoding more threads with lower clock.
it will be software dependent obviously.

 

[DragonQ]

What kind of encoding are you doing? AFAIK using more threads only hurts quality in CBR modes, which are useful for streaming and the like. Offline encoding should always be done using constant quality modes, which should not be affected. As a totally made-up example, let's say you need to use the "slower" preset with 16 threads to match the quality of the "slow" preset with 4 threads. Why does that matter when the former will be way faster anyway?

 

[duffbeer]

All my encoding is offline using constant quality - some x264 and some x265.
It looks like the 9900k beats the 9700k by a decent amount but I have read a couple of forum posts that suggest you shouldn't have threads in double digits. I'm confused but probably over thinking it.

 

[Avalon]

Curve ball - have you considered GPU based encoding? Quality is subjective, if you screen dump/zoom in/compare then you may notice a difference, in real terms that may or may not be noticeable or relevant to you, given your usage/viewing.

 

[duffbeer]

Thanks for the suggestion. Quality is obviously very subjective but every test I have ever seen suggests that GPU encoding is still a long way behind software encoding. The file sizes are also much bigger with GPU encoding.

Still confused to be honest. I can't find anyone who has real world experience with encoding on these processors.

 

[HRL]

I'm sure someone will be along shortly with direct experience but I can't imagine you could go far wrong with a 9900K, or even a 9900X if the price doesn't put you off.

The next Ryzen CPU's out in a couple of months may out perform both but if you need to upgrade now I'd go for one of the above. Currently, on a reasonable budget, the 9900K is king.

 

[duffbeer]

I think the 9900x is a little too pricey. Tempted to check out the new Ryzen CPUs but there's always something better round the corner!

 

[MartinPrince]

...but for video encoding I think the Intel is a better option as they have higher clock speeds and less threads...

Hi, actually your logic here is the wrong way around. For x264 encoding generally speaking the more cores/threads the faster things will be. Clock speed is normally a secondary consideration once you get above decent Mhz.

To give yourself a rough idea of the speed increase then use Cinebench R15 etc as a guide to the x264/x265 encoding performance. Your stock 3770K scores about 700 from what I can see. A 9900K scores ~2000 and the AMD 2700X ~1800.

Either of these will more than double the encoding performance you are getting now. I would opt for the Ryzen system purely from bang for buck. It will be also much easier to upgrade just the CPU in a couple years should you want more performance then.

 

[duffbeer]

I like the idea of going for Ryzen but I have a couple of worries.
1. Some reviews show the 2700x beating a 9700k in x264 and some show exactly the opposite.
2. Lack of iGPU means I need to buy a GFX card and that means there is no real saving.
3. I don't know much about AMD quirks - I've read about memory problems etc.

Being able to upgrade the CPU in a couple of years seems like a VERY good idea.

 

[HRL]

I think the 9900x is a little too pricey. Tempted to check out the new Ryzen CPUs but there's always something better round the corner!

Need to buy now, get the 9900K. Can afford to wait a few more months, take a look at the new Ryzen CPU's once they're out.

That's all you need to think about right now.

 

[DragonQ]

By the way, what OS are you using? If Windows, you might see a nice performance bump by moving to a Linux distro regardless of what CPU you end up going with. Worth comparing using a live DVD or something.

 

[Rainmaker]

I like the idea of going for Ryzen but I have a couple of worries.
1. Some reviews show the 2700x beating a 9700k in x264 and some show exactly the opposite.
2. Lack of iGPU means I need to buy a GFX card and that means there is no real saving.
3. I don't know much about AMD quirks - I've read about memory problems etc.

Being able to upgrade the CPU in a couple of years seems like a VERY good idea.

Are you encoding in software or using hardware acceleration? Given you talk about relying on the iGPU, you're currently either encoding in software (best quality) or using Intel QuickSync. How are you encoding? FFMPEG? Libva? MPV? Handbrake? Other?

If you're insisting on software encoding for ultimate quality (Scene rips etc) then a £10 graphics card just to push your desktop to the screen will do you fine. If you're wanting hardware assisted encoding, not only does that make the Ryzen v Intel question somewhat moot (you'll be relying on the card's acceleration engine rather than the CPU per se) but it also means you'd need to buy a decent card anyway.

What's your budget? It's difficult to make recommendations without one. In your boat I'd probably be looking at Threadripper and moving the task to a Linux OS.

 

[Unseul]

You could get a 2nd hand graphics card, it doesn't need to be anything flash does it? Some online 2nd hand retailers out there sell with decent length warranties. Sure you could find something cheap and cheerful?

 

[MartinPrince]

As Rainmaker has stated, a budget would be good so your replies can be more tailored. As you mentioned 9700K I assumed you might want to save a little cash though if you're really serious about encoding and have the cash to spare then you would look to go Threadripper for a massive improvement in encoding/transcoding speeds.

One important thing to note, the amount of threads does not adversely impact quality. I have a 48 thread encoding rig and I see no difference in quality. Another important point is that I disable HT for my encodes. In my tests my overall encodes were faster when using only actual cores. This is why I would get the 9700K over the 9900K if the choice were between those two.

 

[Orcvader]

I moved from a 2600K overclocked to 4.4GHz to a 1600 at stock speeds, in terms of encoding with Handbrake there's a good boost with x264 files, while x265 while there is some improvements, is much smaller. In terms of quality I haven't noticed any difference from the extra threads.

Generally I would be tempted to go Threadripper instead due to the extra core count at a similar budget, but I find x265 does seem to prefer stronger cores over more threads. I would say if you can, wait for the Ryzen 3000 series to appear and see what it offers and at what price. Whether it does better or not, it should prompt Intel to react with something which will end up being better for you price wise.

 

[Avalon]

If you aren’t going to use a GPU for anything significant, anything with compatible drivers will do the job, you can buy a £10 GPU. The difference between a 2700x and any of the 9 series mentioned is going to buy you more GPU’s than you can physically use. Memory issues were a launch/1st gen issues, unless people are running relatively ancient BIOS versions then it’s largely a non event at this stage. I run a mix of x99 based Xeon’s and 1st gen Ryzen chips at present, I personally had zero issues, at worst i’d have had to set manual timings. Ryzen today is a different prospect to launch day, even then the issues were largely down to completely new platform/architecture which was expected to need time to mature and gain OOTB support.

 

[duffbeer]

As Rainmaker has stated, a budget would be good so your replies can be more tailored. As you mentioned 9700K I assumed you might want to save a little cash though if you're really serious about encoding and have the cash to spare then you would look to go Threadripper for a massive improvement in encoding/transcoding speeds.

One important thing to note, the amount of threads does not adversely impact quality. I have a 48 thread encoding rig and I see no difference in quality. Another important point is that I disable HT for my encodes. In my tests my overall encodes were faster when using only actual cores. This is why I would get the 9700K over the 9900K if the choice were between those two.

I don't have a specific budget. I am willing to spend more if the performance is significantly better. I realise that sounds a little vague but that's my train of thought at the moment.

Interesting to read your comment about extra threads not affecting quality but your point about disabling HT is what concerns me. Some reviews put the 9900k x264/x265 speeds way above the 9700k and some only slightly above.
I'm tempted by the upgrade possibilities with Ryzen but from what I can see the threadripper doesn't have any advantages (for my usage) over the 9900k.