Hi,
 
For SONAR, do I go for more cores or faster clock?
 
Which of the above CPUs do I choose?
 
Regards,

There are some pretty good tech papers on the net that analyze this very question, not necessarily relating to Sonar but to CPU-intensive operations. As I read it, in general with the current state of the art in multi-core, you can achieve greater through-put with fewer cores running at higher clock speeds. As always, YMMV.
 
That being said, since I'm an unabashed geek, more cores is always better, even if it's not. :)

Ideally, you want fast clock-speed *and* more cores.
You really don't want to sacrifice one for the other.
(If it's a large difference in clock-speed, I'd go with fewer cores running significantly faster.)
 
The 6700k is barely hitting the street.
I'd sit out the first gen motherboards... and let the issues settle.
 
You'd be very pleased with a six-core 5820k running at 4-4.5GHz.  
 

Depending on what you are doing it may not matter much. I have a 5930K running at 4GHz and nothing I do comes even close to making any real use of it. I think maybe 30-40% load is the max I've managed. My old 2600K wasn't having any issues either, I just wanted a new toy.
 
If you load things real heavy it can matter, but if not it isn't a big deal usually. Audio has really been getting "easy" these days, computers tend to have more power than is needed for most things.
 
If you are wanting to go for the 6 core option I'd think about overclocking it personally. They OC real easy and then you can have some good speed AND higher core count. Even a really bad sample will hit 4GHz no issue, and most will do 4.2-4.4GHz with a normal air cooler.

Funny, I got back from buying an I7-5820K at Microcenter like 10 mins ago. I did a lot of research on 5820 vs 4790 vs 6700. If you want a future upgrade path (no guarantees) go 6700 (1151 skt).
If you want a cheap but powerful system go with 4790 (1150 skt obsolete)
Since my new studio PC build will do nothing else but audio and the 5820 (2011 skt) may have one more  generation of upgrades with broadwell or the 8-core I7-5960X ($850+), I went that route. I intend to overclock the 5820 up to 4.5Mhz (@6 cores) if I can get that high.
For the 6700 or the 5820, you pay more for DDR4 RAM and maybe a bit more for the motherboard than with the 4790.
My 4790 build estimate was about $1100. (32GB DDR3 RAM, 2 SSDs/1TB HDD w/o video card, $60 cooler and $70 case).
My 5820 real build (32GB DDR3 RAM, 2 SSDs/1TB HDD w/o video card) is about $1550 of which $110 is the OC cooler and another $140 for the case. The DDR4 32GB was $259.
So $200-300 more for the 5820 vs 4790 depending on case and OC vs no OC. You could certainly put together a very respectable 4790 system for < $1000 even with video card.
I did not do a 6700 estimate since I cannot find one I can get my hands on.
 
If you are worried about a new motherboard supporting a future processor, no one really knows.
I would expect the Skylake 1151 socket to last a least a generation or two, but Intel has not told us what their plans are for future sockets past Skylake.
For Sonar or other multithreaded DAWs, I think more cores is slightly more important than raw clk speed but both is better still. Unless you are using multiple monster samplers or heavy duty multiple synths with tons of VST effects, the 4 core CPUs (4790, 6700) will be more than enough.
BTW, Microcenter has 5820 for $299, 4790 for $279 (I think).This is $90 off 5820, $60 off 4790. In store only. I could not find anyone with the 6700 yet but I read it will be ~$400.
The remaining parts for my build will arrive Thu, I will post how it goes.

Great posts with useful data, kudos to all!

Hey guys,
 
Thanks for the helpful information.  I think I'm going to go for the 5820 and get a proper cooler for when I push the CPU to 95% :)
 
Regards,
B

Not a bad plan. Personally the Arctic Cooling Freezer i30 is what I got for mine. Positively massive, but fits without blocking any components. Plenty of overhead for overclocking.

If over-clocking the 5820k to 4.5GHz, you want high-performance cooling.

Also check out Noctua's NH-D14 cooler......as you can see it's a real beast, and will probably need a full ATX case, but it's a fantastic cooler (OC'ing or not).