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I recently upgraded My computer from a EVGA 780 and an EVGA 970 to 2 ZOTAZ 780ti's and a single EVGA 780. And I've only noticed a slight decrease with render times. I was kind of hoping for more than a 10%-15% difference with 3 times the power. Other build specs: AMD 8350, 32GB Corsair Dominator DDR3, 500GB Samsung EVO SSD, Ultra 850W PSU.

I've watched Understanding Octane For C4D and know how to adjust render settings accordingly. And I'm currently rendering out a pretty simple scene.

Just wondering if anyone had any insight.

Thank You

Did you have good air between the two cards and now you have three cards close to each other?
(If the cards have less airsace they perform less because they get hot quicker.)

Unfortunately I had to sacrifice airflow between 2 of the cards. But they don't go over 70....even while rendering. which is about the same the 780 always sat at before during renders. But still....there should be a lot more difference in render times.

You should watch gpu usages and do some math to calculate expected performance. Octane linearly scales the gpu power if there is not any other factor.

that PSU is likely BARELY supporting all 3 cards.

Download techpowerup gpu-z or a similar program to watch the gpu usage (like stated by aoktar)
https://www.techpowerup.com/gpuz/ - seems like something is throttling the cards (might be PSU) - the cards should go over 70° with this setup, I think.

When I looked up what PSU would be best for this setup, I found that a 1000W should have been sufficient and a 1300W would be plenty. I was running the 2 780ti's and a 960 on a 850W with no problems. I just ran the Octane bench and got a 280. Which is around the same as 3 Titan Blacks.

What do I need to look for when running GPU-Z?

CCIDgfx wrote:When I looked up what PSU would be best for this setup, I found that a 1000W should have been sufficient and a 1300W would be plenty. I was running the 2 780ti's and a 960 on a 850W with no problems. I just ran the Octane bench and got a 280. Which is around the same as 3 Titan Blacks.

What do I need to look for when running GPU-Z?

Check gpu usage percentages. You should see how much is used on rendering. If they are near to %100 it's ok.

All 3 GPU's at 99% when rendering.

CCIDgfx wrote:All 3 GPU's at 99% when rendering.

Just check priority of your cards .