Slower Processor, but not an issue with RTX 3000 video card and x13?

[aslan-Ryan]

Hello power users,

 

I have a fairly old Intel i7-6700 CPU (4 cores, 3.4 GHz) that struggles with physical based rendering times...and from what I understand the speed bottleneck in running x12 is the processor.  Up to today I was thinking that it would be best to shell out several grand to get a new PC with an RTX30xx graphics card to handle the new live ray tracing feature when we upgrade...

 

However, I remembered that the new version supposedly handles these rendering tasks on the graphics card in x13, and RTX 30xx cards are compatible with my motherboard.  Wondering what your thoughts are on simply shelling out the $1000+ on an RTX30xx card with my existing motherboard/processor and the rendering speeds with x13?  

 

Where I see the biggest lag is in physically based rendering with improve lighting enabled in x12, or if I have a 3D perspective open and make changes in the plan on a secondary monitor.

 

Thanks,

Ryan 

[MarkMc]

Be a good idea to fill out your signature with complete system info.

Until recently I'd been running 17" laptop with a 6700k, GTX980m 8GB Vram, 32 GB ram, fast M2 Nvme, with two 27" 2k external monitors. Was pretty good in 12 and tested in 13 and also ran ok. I'd already planned on getting a new machine. Laptop end of the summer is just a little snappier than that was, desktop this spring is faster. Both do real time ray trace which was the purpose.

What to do depends on your total system now? then budget, type of work, and future plans. One issue is that the next gen of AMD and Intel CPUs are changing sockets so won't be upgradeable. Other thing is coming generation of GPUs are supposed to be a big leap in performance, third is that current GPU market is not great but improving.

 I normally look at 4-5 years for a system but might be changing the desktop sooner depending on what happens in the next year or two. I knew that before purchasing though but felt I needed RTRT.

For reference- PBR in both 12 and 13 will peg GPU at 100% (all 3 machines), x12 usually uses 6GB Vram; 13 is 4-5. CPU use is not as much of an issue with PBR but was a bit higher with the 6700K

Standard views with 6700 would see CPU peg briefly, not so with 13.

Multiple views, other programs see ram usage though 16GB is fine. A fast C drive makes a big difference.

 

At this point if it were me and I could tolerate waiting to mid winter I would prefer that but a lot depends on the complete system you have now.

 

[Kbird1]

3 hours ago, aslan-Ryan said:

I have a fairly old Intel i7-6700 CPU (4 cores, 3.4 GHz) that struggles with physical based rendering times...and from what I understand the speed bottleneck in running x12 is the processor. 

 

PBR ( and the new PBR-RT or RTRT )  do not use the CPU , only the old style Raytracing ( Addon) is CPU based , in Preferences you can even set the number of cores for it to use, the New Lighting Engine is GPU based ( DirectX12U) and it is best to handled by the 3000 series, even more so than the 2000 Series.

 

The pricing of 3000 Series cards is come down, not 100% sure you'll still find anything at MSRP though due to supply issues, so you could try the Card 1st in the current system but you are at the point of a new system so it is definitely a reason to think on a whole new system which includes a 3000 eg the system Mark has in his sig. above from AVA.

 

M.

[puntloos]

How can I tell if rendering is using my 3080 GPU? It certainly is raytracing (the telltale speckle with ever smaller graininess) but whenever I move my 1920x1200(ish) viewport it takes about 10 seconds to go from the start until 'acceptable'.

Shouldn't that be less? Could it be it is using my fairly powerful CPU instead?

 

In the task manager neither CPU nor GPU seem to be breaking a sweat but if anything I *want* them to break a sweat to be faster...

[Kbird1]

All sounds about normal to me .....

 

check Preferences > Render Tab for GPU info

 

Looks like you need to update your Signature too.....3080 vs 2080

[puntloos]

Ah thanks indeed it shows it's enabled. Yes upgraded to 3080 recently!