Hello,

I am planing to update my pc.
Getting totally new one or updating existing one.
Wanted t know what is most important?
CPU
GPU
or
DDR4

Also if CPU is hypherthreading important and more threads more helpful regaring boosting mantra rendering for example?

I do time to time Play also PC games.
This means that need pc that can handle verry well simulations and rendering but same time can play latest games on max settings with no problems.

Trying to find out is the i7 good idea (note cant spent 1500 on cpu as then i have only 500 euros left for motherboard)

I currently have old PC
Motherboard Name Asus Rampage III Extreme (1 PCI, 1 PCI-E x4, 4 PCI-E x16, 6 DDR3 DIMM, Audio, Gigabit LAN, IEEE-1394)
Motherboard Chipset Intel Tylersburg X58, Intel Westmere
DIMM1: Corsair Dominator CM3X2G1866C9D 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (6-6-6-16 @ 444 MHz)
CPU Type HexaCore Intel Core i7-970, 3200 MHz (24 x 133)
Video Adapter NVIDIA GeForce GTX 780 (3 GB)
Disk Drive OCZ-VERTEX2 ATA Device (SATA-II)
Disk Drive WDC WD1002FAEX-00Z3A0 ATA Device (1 TB, 7200 RPM, SATA-III)

got also SSD and 7200 rpm velocy raptor hdd

Later planed to max pc to 128 gb ram (ddr4)
and as i understand this means getting x99 motherboard

Planing also to use Mari for texturing
zbrush for sculpting and after effects for some stuff
And dont want to tie myself only wiht one rendering engine

Hello,

i just bought a new PC myself(mostly for Houdini Dynamics/Compositing/VFX like stuff )
Have you thought about buying the i7-5820k? Matter of budget, but price/value for this one seems to be really nice to me.
Multithreading Hexacore - for me, used to work with an i5-2400, its just fancy stuff!

I'd say CPU would be the most critical part for most of the Rendering/3D/VFX/Compositing stuff. As far as you do now want to use GPU renderer like Octane. (But tbh, i am no specialist here!)
Since i would have had to upgrade all major parts anyway, i decided to buy a new one.
I added Nvidia 1060 GTX and 16GB of RAM for now. As soon as prices are dropping, i want to upgrade to 32GB, but at the moment prices are just too high.

At least for now, i did not run in any issues with the amount of RAM.
Sadly i'm not familiar with Mari/texturing or zbrush. So i can't help you here.

Hope, this might help you a bit

Cheers

You'll want a minimum of 32GB of RAM, and an 8-core GPU would be a good choice (I would consider a 6-core CPU a minimum for rendering and sims). The GPU doesn't matter for rendering at this point, unless you use the OpenGL ROP.

The Intel i7 6900K would be a good choice. If you're looking at more of a budget build, you may consider a AMD Ryzen 1800X, at nearly half the price of the Intel CPU but with most of its performance.