Best Hardware for GPU Rendering in Octane – Redshift – Vray (Updated)

22 March 2017

Graphics Card (GPU) based render engines such as Redhift3D, Octane or VRAY-RT have matured quite a bit over the last years and are starting to overtake CPU-based Render-Engines.

But what hardware gives the best-bang-for-the-buck and what do you have to keep in mind when building your GPU-Workstation? What is the best Hardware and best GPU for rendering with Octane, Redhsift3D or VRAY-RT, that is affordable?

Processor

Since GPU-Render Engines use the GPU to render, technically you should go for a max-core-clock CPU like the Intel i7 7700K that clocks at 4,2GHz (4,5Ghz Turbo) or the Intel i7 8700K that clocks at 3,7Ghz (4,7Ghz Turbo).

That said though, there is another factor to consider when choosing a CPU: PCIE-Lanes.

GPUs are attached to the CPU via PCIE-Lanes on the motherboard. Different CPUs support different amounts of PCIE-Lanes and Top-tier GPUs usually need 16x PCIE 3.0 Lanes to run at full performance.

The i7 7700K/8700K has 16 PCIE-Lanes meaning you could use only one GPU at full speed with these type of CPUs. If you want more than one GPU at full speed you would need a different CPU that supports more PCIE-Lanes like the AMD Threadripper CPUs, that have 64 PCIE-Lanes, the i9 7800X (28 PCIE-Lanes) or the i9 7900X Series CPUs that support 44 PCIE-Lanes.

GPUs, though, can also run in lower speed modes such as 8x PCIE 3.0 Speeds and then also use up less PCIE-Lanes (8x). Usually there is a negligible difference in Rendering Speed when having GPUs run in 8x mode instead of 16x mode.

This would mean you could run 2x GPUs on an i7 8700K in 8x PCIE mode, 3x GPUs on an i9 7800X and 5x GPUs on an i9 7900X. (Given the Mainboard supports this configuration)

PCIE_Lanes Compariosn

When actively rendering and your scene has been loaded into the GPU VRAM, it fits nicely in there and nothing has to be swapped out of core, GPU renderers are of course mainly dependent on GPU performance.

Some processes though that happen before and during rendering rely heavily on the performance of the CPU, Hard-Drive and network.

For example extracting and preparing Mesh Data to be used by the GPU, loading textures from your Hard-Drive and preparing the scene data.

In very complex scenes, these processing stages will take lots of time and can bottleneck the overall rendering speed, if a low-end CPU, Disk and RAM are employed.

If your scene is too large for your GPU memory, the GPU renderer will need to access your System RAM or even swap to disk, which will considerably slow down the rendering.

Best Graphics Card for Rendering

To use Octane and Redshift you will need a GPU that has CUDA-Cores, meaning you will need a NVIDIA GPU. VRAY-RT additionally supports openCL meaning you could use an AMD card here.

The best bang-for-the-buck NVIDIA cards are 1070 GTX (1920 Cuda Cores, 8GB VRAM), 1080 GTX (2560 Cuda Cores, 8GB VRAM) and the 1080 Ti (3584 Cuda Cores, 11GB VRAM).

On the high-end, the currently highest possible performance is offered by the NVIDIA Quadro P6000, that also comes with 24GB of Video RAM. This Card though has horrible Performance per Dollar (Check the tables further down).

NVIDIAs new Volta architecture, that is being released for consumers soon, will top this performance even more. Note though, that the Render Engines you are using will have to be updated in Order to use the New CUDA 9 Architecture these Volta Cards run on.

GPUs, that have 12GB Video RAM and more, can handle high-poly scenes with over 200 million unique objects best. Take a look at the performance per dollar tables below, though, to get an overview of how expensive some of these cards can get without offering that much more performance.

GPU Cooling

Founders Edition Blower Style Cooler

  • PRO: Better Cooling when stacking more than one card
  • CON: Louder than Custom Partner Card Cooling

Custom Partner Cooling

  • PRO: Quieter than Blower Style, Cheaper
  • CON: Worse Cooling when stacking cards

Hybrid Cooling

  • PRO: Best All-In-One Cooling for stacking cards
  • CON: More Expensive, needs room for radiators in Case

Watercooling

  • PRO: Best temps when stacking cards, Quiet
  • CON: Needs lots of extra room in the case for tank and radiators, More Expensive

Power Supply

Be sure to get a strong enough Power supply for your system. Most Cards have a TDP of around 180-250W. CPU of around 100W and any additional Hardware in your case.

I Recommend a 500W for a One-GPU-Build. Add 250W for every additional GPU. Good PSU manufacturers to look out for are beQuiet, Seasonic and Coolermaster (among others)

Mainboard & PCIE-Lanes

Make sure the Mainboard has the desired amount of PCIE-Lanes and does not share Lanes with Sata or M.2 slots. Also be careful what PCI-E Configurations the Motherboard supports. Some have 3 or 4 PCI-E Slots, but only support one x16 PCI-E Card.

This can get quite confusing. Check the Motherboard manufacturers Website to be sure the Card configuration you are aiming for is supported. Here is what you should be looking for in the Motherboard specifications:

Asus Rampage PCIE Lane Config

In the above example you would be able to use (with a 40 pcie Lane CPU) 1 GPU in x16 mode. OR 2 GPUs in both x16 mode OR 3 GPUs one in x16 mode and two of those in x8 mode and so on. Beware that 28 pcie Lanes CPUs in this example would support different GPU configurations than the 40 lane CPU.

Currently the AMD Threadripper CPUs will give you 64 PCIE Lanes to hook your GPUs up to, if you want more you will have to go the multi-CPU route with Intel Xeons.

To confuse things a bit more, some Mainboards do offer four x16 GPUs (needs 64 PCIE-Lanes) on CPUs with only 44 PCIELanes. How is this even possible?

Enter PLX Chips. On some motherboards these chips serve as a type of switch, managing your PCIE-Lanes and leads the CPU to believe fewer Lanes are being used. This way, you can use e.g. 32 PCIE-Lanes with a 16 PCIE-Lane CPU or 64 PCIE-Lanes on a 44 Lane CPU. Beware though, only a few Motherboards have these PLX Chips. The Asus WS X299 Sage is one of them, allowing up to 7 GPUs to be used at 8x speed with a 44 Lane CPU, or even 4 x16 GPUs on a 44 Lanes CPU.

This screenshot of the Asus WS X299 Sage Manual clearly states what type of GPU-Configurations are supported (Always check the manual before buying expensive stuff):

Asus WS X299 Sage

PCIE-Lane Conclusion: For Multi-Gpu Setups, having a CPU with lots of PCIE-Lanes is important, unless you have a Mainboard that comes with PLX chips. Having GPUs run in x8 Mode instead of x16, will only marginally slow down the performance. (Note though, the PLX Chips won’t increase your GPU bandwith to the CPU, just make it possible to have more cards run in higher modes)

Best GPU Performance / Dollar

Ok so here it is. The Lists everyone should be looking at when choosing the right GPU to buy. The best performing GPU per Dollar!

This List is based off of OctaneBench 3.

(It’s quite difficult to get an average Price for some of these cards, since crypto-currency mining is so popular right now, so I used MSRP)

GPU NameVRAMOctaneBenchPrice $ MSRPPerformance/Dollar
GTX 107081204000,300
GTX 1070 TI81304500,288
GTX 10608843000,280
GTX 1080 TI111867000,265
GTX 108081375500,249
TITAN XP1219113000,146
GTX TITAN Z1214429990,048
Quadro P60002417638490,045
Quadro GP1001623270000,033
Tesla P1001623075000,032

 

And here is a List based off of Redshift Bench, note how the cards scale (1080TI) [RedshiftBench Mark (Time [min], shorter is better)]:

GPU NameVRAMRedshiftBenchPrice $ MSRPPerformance/Dollar
GTX 1070817.114001,461
GTX 1080 TI1111.447001,248
4x GTX 1080 TI113.0728001,163
2x GTX 1080 TI116.1514001,161
8x GTX 1080 TI111.5756001,137
GTX 1080816.005501,136
TITAN XP1210.5413000,729
Quadro P60002411.3138490,229
Quadro GP100169.5770000,149

Source: Redshift Forum

 

And here is a List based off of VRAY-RT Bench. Note how the GTX 1080 interestingly seems to perform worse than the GTX 1070 in this benchmark:

GPU NameVRAMVRAY-BenchPrice $ MSRPPerformance/Dollar
GTX 107081:25 min4002,941
GTX 1080 TI111:00 min7002,380
2x GTX 1080 TI110:32 min14002,232
GTX 108081:27 min5502,089
4x GTX 1080 TI110:19 min28001,879
TITAN XP120:53 min13001,451
8x GTX 1080 TI110:16 min56001,116
TITAN V120:41 min30000,813
Quadro P6000241:04 min38490,405

Source: VRAY Benchmark List

Speed up your Multi-GPU Rendertimes

So unfortunately GPUs don’t scale linearly. 2 GPUs render an Image about 1,8 times faster. Having 4 GPUs will only render about 3x faster. This is quite a bummer, isn’t it? Having multiple GPUs communicate with each other to render the same task, costs so much performance, that one GPU in a 4-GPU rig is basically just managing decisions.

The solution is the following: When final rendering image sequences, use as few GPUs as possible per task. If you have to render 4 images and have 4 GPUs, let every GPU render one image instead of having 4 GPUs render on every image. This way you will not encounter any slow-down. Some 3D-Software might have this feature built-in, if not, it is best to use some kind of Render Manager, such as Thinkbox Deadline (Free for up to 2 Nodes/Computers).

Beware though, that you might have to increase your System RAM a bit and have a strong CPU, since every GPU-Task needs its amount of RAM and CPU performance.

 

What Hardware configurations are you eyeballing with, or have already been able to test? Share your thoughts in the comments!

 

Alex - post author

Hi, I am Alex, a passionate Director and 3D Generalist currently working in an Animation Studio.

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swaroop
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Hi, Aelx
Can i use 4 GPUs (my preference 1070) with 7700k? for octane.
If can, then which Motherboard to choose.
Thanks

ANDRES GARCIA CASTILLO
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ANDRES GARCIA CASTILLO

Hi, Aelx

Good Post!

A question if I want to have 4 gtx1080 in a corei7 6800k that would have lost for rendering with octane? Is insignificant? or it would be worth buying 6850k to be able to have the 4 gtx.

And what kind of cooling you recommend for these 4x gtx1080, thank you very much for your time!

Cheers,
Andres

Frank Gomez
Guest

Hi Alex,

Thank you for your posts, they are very helpful. Two questions:

1. Regarding the i7-7700K. If I use 1TB Samsung 960 EVO M.2 NVMe PCIe in my build. Would this affect the PCI lanes for the GPU? Or would the GPU still run x16?

2. If I want to run 4 GTX 1080ti at full speeds (x16), would i have to move to the Xenon processors? What mobo should I use?

Thanks Again.

Frank

Deb Pearl
Guest

My son has been looking for a new graphics card and I wanted to look up some information about them. That is great news that they have matured quite a fit over the last couple of years. That means my son could probably find exactly what he wants for his computer easier. Thank you for all the information! I will be sure to show my son.

Polystorm
Guest

Hi Alex. Your blog posts have really helped me understand pc builds for working in Cinema 4D. I’m trying to do a build with the i7 7700k and 4x1080ti cards on PCPartpicker. I can’t seem to find information on a motherboard that would support this configuration. Any advice? Thank you in advance!

Kurt jefferson macacando
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Kurt jefferson macacando

Hi sir.. im planning to have my first ever cpu.. im planning to have a i7 7700k processor and a gtx 1070 8gb gpu.. and a 16gb ram.. can i have a fast rendering time for vray 3.0 sketchup 2017? Or a ryzen 5 1600 processor due to its 6 cores and 12 thread.. im a bit confuse.
Due to tight budget.. i really need your help for this..

Thank you sir!

Tiago
Guest

Hi Alex

First of all, great post, congrats!
My concern is about GPU’s, i want to build a rendering workstation for 3ds max + Vray 3.6 and in terms of graphic cards i’m planning to use a gtx 1070 for viewport and a gtx 1080 ti for render and add 1 or 2 more gtx 1080 ti in the future.
My doubt is, it is possible to have different cards in the same build? i’m asking this, because all the people that i see building this kind of machines with multiple gpu’s, uses the same cards.

Thank you in advance.

Jay
Guest

Hi Alex, first off – thank you so much for all this useful knowledge on this site, learning a lot about how I should go about building my first PC for Octane for Cinema 4D and some Aftereffects motion design.

I am torn between the i7 7700K and the 8700K, I’m planning to buy one GTX 1080Ti and add another one in the near future. If I was to go up to 2, and maybe even 3 or 4 1080Ti’s in the future, which MoBo should I consider?

Druid
Guest

Alex,
Great info! Question: Have you noted the impact of overclocking (GPU and/or CPU) with respect to the results in your charts? When comparing my configuration results in VRAY Bench to the ones listed on the website, I score in the middle of similarly-configured systems. If I run everything at stock speeds, I’m out in left field. I’d be interested in your take on this, if any.

Eddy
Guest
Hi Alex, I’m upgrading my workspace by building up a new render station for Redshift and Octane. My issue is that im torn between wither going the Ryzen route or the new 79xx route. The reason being, I want to run either 3 1o8oti’s or 4 1080s at the best speed possible. Looking at the require PCIe lanes available, i need your advice or what could potentially work best and still be future proof. I know i will get more PCIe lanes on ryzen i just havent jumped on it before. Could you recommend some ideal compatible parts for a… Read more »
jeremy
Guest

Hi Alex, I was curious if you had seen any testing in regards to the new Titan V with redshift?

Cheers,

Silas
Guest
Hi Alex I recently built a 1950X machine for multiple purposes (VRay RT, AE, Premiere Pro, Audio): 1950X 1080Ti & 1080 64 GGB DDR4 The problem is that I found out now that the 1950X has some problems with the navigation in After Effects (and it has problems with an audio tool I often use). I really want to switch to a 8700K. The only thing that held me back was the thought of not being able to render at the same speed in 3D. But after reading your post, the 8700K would be the better solution for GPU renders… Read more »
Adam
Guest

Hi Alex,
I am looking for a workstation configuration for redshift and octane in combination with C4d. I am planning to go with 4 gtx1080ti’s or free with any other good option. Could you please guide me with the configuration of cpu and motherboard and Gpu’s also.
Thanks in advance
Adam.

Ziee
Guest

Hey Alex,

Thank you for the nice article.
As an architect I will use my computer for complex modeling plus rendering and I guess that needs a processor with max of cores (the more the better).
The problem is the more cores the less core-clock CPU.
What do you think and suggest dear Alex?

Best regards,
Zied

Marc
Guest
Hello Alex, Thank you very much for sharing your knowledge. Very usefull. I would like to ask you one thing, because I’m going crazy and I’m desperate with my computer problems. I’m recently using a new computer (I bought from a company specialized in 3d work), with x4 1080ti – Windows 10 – Intel Xeon E5-1650… . I’m using Cinema 4d and Octane and some weeks ago I’ve been experimenting a lot of blue screens, screen freezes, render crashes,etc.. I can’t render a scene by night because always crashes. I’ve noticed in Octane forums that a lot of people have… Read more »
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