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View Full Version : PC build - advice welcomed...



Darthpistachio
02-21-2018, 03:30 PM
Hi all

that time has come round again where I'm in need of a hardware upgrade as the software has outgrown my current rig..

I'm having trouble deciding between processors though and would appreciate any input..

I 'm trying to decide between an i7-8700K - with 6 cores and 12 threads
OR
an i7-7820X with 8 cores and 16 threads..

benchmarks rate the latter as slightly slower than the former and the cost difference is substantial as the latter is nearly twice the price - needs an X299 Mobo and Quad channel ram

The question is would I notice any real world difference between the two in lightwave when rendering to make the additional cost worth it?


bear in mind i'm also upgrading from an aging AMD FX6200 - 6core

advice appreciated

marchermitte
03-02-2018, 04:31 AM
amd threadriper 1950x. Watercooled.

Snosrap
03-02-2018, 03:01 PM
Is it better to go with more cores/threads over Ghz speed for rendering?

paulk
03-03-2018, 08:19 AM
What about one or more high-end nVidia cards and Octane?

Snosrap
03-03-2018, 09:04 PM
What about one or more high-end nVidia cards and Octane?

Can't afford. :)

rsfd
03-04-2018, 03:08 AM
Is it better to go with more cores/threads over Ghz speed for rendering?
No, not necessarily.
It depends on the relationship between these two variables.

A lower clocked CPU with more cores can outperform a higher clocked CPU with lesser cores on multithreaded tasks like rendering.
But it can be the other way round too: i.e. an 8-core with higher clock speed can outperform a 10- or even 12 core-CPU with lower clock speed.

So one needs to carefully research what CPU suits ones personal needs the best.
If you also need performance for other applications that aren't that good multithreaded, a higher clocked CPU with lesser cores might be the best compromise.
But it really depends on the personal needs.

If budget comes into play, you got a 3rd variable to consider.
Under these circumstances, the AMD Threadripper actually seems to be one of the most interesting CPU.

rsfd
03-04-2018, 03:29 AM


benchmarks rate the latter as slightly slower than the former and the cost difference is substantial as the latter is nearly twice the price - needs an X299 Mobo and Quad channel ram

The question is would I notice any real world difference between the two in lightwave when rendering to make the additional cost worth it?
From what I gathered, performance in applications (not Games!) is better on the 7820X (7820X=100%; 8700K=85%).
This would make it the more interesting CPU. (Games performance is closer together, but I don't care about these benchmarks).
If you can afford that CPU, I would go with it.

But: as marchermitte already noted, I also would suggest to consider the AMD Threadripper (if this could be an option price wise).

vncnt
03-04-2018, 04:07 AM
If you use it a lot for rendering you could do some research for a multi pc setup, incl. the old pc.
You don't need an expensive GPU when rendering native LW.

rsfd
03-04-2018, 08:08 AM
^ but network rendering with 2 or more machines on mixed performance levels (old/new CPUs), can slow down the process instead of speeding it up (>task management).

papou
03-06-2018, 04:41 PM
I have a 56 cores machine. Yes that's great for rendering. But lot apps aren't multithreaded well.
So my advice is get the highest clock Cpu, if it is your main workstation for modeling and compositing too.
It is a pain in the *** to see your Cpu's average at 2%...