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I am running blender on GPU. I remark that there is no high difference between CPU and GPU as not expected. What is the problem?

CPU information:

*

>     Architecture :        x86_64
>     Mode(s) opératoire(s) des processeurs : 32-bit, 64-bit
>     Boutisme :            Little Endian
>     Processeur(s) :       8
>     Liste de processeur(s) en ligne : 0-7
>     Thread(s) par cœur : 2                                                                             
>     Cœur(s) par socket : 4                                                                             
>     Socket(s) :           1                                                                            
>     Nœud(s) NUMA :       1                                                                             
>     Identifiant constructeur : GenuineIntel                                                            
>     Famille de processeur : 6                                                                          
>     Modèle :             26                                                                            
>     Nom de modèle :      Intel(R) Xeon(R) CPU           W3520  @ 2.67GHz                               
>     Révision :           5                                                                             
>     Vitesse du processeur en MHz : 1596.000                                                            
>     Vitesse maximale du processeur en MHz : 2661,0000                                                  
>     Vitesse minimale du processeur en MHz : 1596,0000                                                  
>     BogoMIPS :            5320.06                                                                      
>     Virtualisation :      VT-x                                                                         
>     Cache L1d :           32K                                                                          
>     Cache L1i :           32K                                                                          
>     Cache L2 :            256K                                                                         
>     Cache L3 :            8192K                                                                        
>     Nœud NUMA 0 de processeur(s) : 0-7

*
**GPU information:**



> *02:00.0 VGA compatible controller [0300]: NVIDIA Corporation GF104 [GeForce GTX 460] [10de:0e22] (rev a1) (prog-if 00 [VGA controller])
>            Subsystem: Gigabyte Technology Co., Ltd Device [1458:34fa]
>            Flags: bus master, fast devsel, latency 0, IRQ 53
>            Memory at bc000000 (32-bit, non-prefetchable) [size=32M]
>            Memory at c0000000 (64-bit, prefetchable) [size=128M]
>            Memory at c8000000 (64-bit, prefetchable) [size=64M]
>            I/O ports at 2000 [size=128]
>            [virtual] Expansion ROM at be000000 [disabled] [size=512K]
>            Capabilities: <access denied>
>            Kernel driver in use: nvidia
>     
>     02:00.1 Audio device [0403]: NVIDIA Corporation GF104 High Definition Audio Controller [10de:0beb] (rev a1)
>            Subsystem: Gigabyte Technology Co., Ltd Device [1458:34fa]
>     --
>     03:00.0 VGA compatible controller [0300]: NVIDIA Corporation GT218 [GeForce 210] [10de:0a65] (rev a2) (prog-if 00 [VGA controller])
>            Subsystem: ASUSTeK Computer Inc. Device [1043:8354]
>            Flags: bus master, fast devsel, latency 0, IRQ 54
>            Memory at b8000000 (32-bit, non-prefetchable) [size=16M]
>            Memory at d0000000 (64-bit, prefetchable) [size=256M]
>            Memory at ce000000 (64-bit, prefetchable) [size=32M]
>            I/O ports at 3000 [size=128]
>            [virtual] Expansion ROM at b9000000 [disabled] [size=512K]
>            Capabilities: <access denied>
>            Kernel driver in use: nvidia
>     
>     03:00.1 Audio device [0403]: NVIDIA Corporation High Definition Audio Controller [10de:0be3] (rev a1)
>            Subsystem: ASUSTeK Computer Inc. Device [1043:8354]*

Path tracing sample is 1000.

I tried the GPU with tile size=256, 512, 1024 and with 500, 250, 150 samples but I remark that for 2hours or 3 hours, it rendered only 66 frames. It is very slow!!!

BetterEnglish
  • 2,000
  • 4
  • 29
  • 53
  • 2
    What GPU and what CPU? – gandalf3 Mar 23 '15 at 19:47
  • 1
    what GPU do you have? – Denis Mar 23 '15 at 19:47
  • 4
    What is the size of the rendering tiles? how big are your textures? what kind of GPU are we talking about? what kind of CPU? how much RAM?, does the scene involve physics or particles? It's hard to guess what you are doing and what your expectations are. Please add more info to your question. –  Mar 23 '15 at 19:53
  • That is almost the same GPU/CPU that I have, and my GPU is definitely faster. What tile size are you using then? GPU's generally go faster on larger tiles and slower and smaller tiles. CPU's tend to do the reverse. – gandalf3 Mar 23 '15 at 20:05
  • @gandalf3, path tracing sample is 1000. – BetterEnglish Mar 23 '15 at 20:11
  • @gandalf3, How can I specify the path tracing tile in blender 2.72 – BetterEnglish Mar 23 '15 at 20:15
  • @startingBlender The tile size can be set in Render settings > Performance. Try setting it to something like 128 or 256 and see if the GPU render times decrease. – gandalf3 Mar 23 '15 at 20:16
  • @gandalf3, it is necessary to check the progressive refine option ? What is the utility of this option – BetterEnglish Mar 23 '15 at 20:31
  • related: http://blender.stackexchange.com/questions/24167/why-are-there-scenes-that-will-not-render-on-gpu-but-will-render-fine-on-cpu –  Mar 23 '15 at 20:54
  • @startingBlender No. See http://blender.stackexchange.com/a/4981/599 for an explanation of that option. – gandalf3 Mar 23 '15 at 21:28
  • @gandalf3, I tried the GPU with tile size=256, 512, 1024 and with 500, 250, 150 samples but I remark that for 2hours or 3 hours, it rendered only 66 frames. It is very slow!!! – BetterEnglish Mar 30 '15 at 21:59
  • Well, to be honest problem is that you have a nicely powerful CPU and low price GPU. I wouldn't wonder why it's same time, have in mind that GTX 460 is NOT the best CUDA performance. To get decent speedup, you need to go for something that costs at least same as your CPU. – Migol Mar 30 '15 at 22:09
  • @Migol, I have not exactly understood what you said. You mean that I have that GTX 460 is not the best graphics card? What the best GPU then? – BetterEnglish Mar 30 '15 at 22:14
  • @startingBlender you should take a look at specifications of different NVIDIA GPU's. your GTX 460 (http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-460/specifications) has 336 CUDA cores. These are like cores in a CPU, only many many more. Top 4 series GPU - GTX 480, had 448 cores (50% more). And GTX 780 which I use has 2304 CUDA cores, hence why I get a lot of speed up. Remember also that CPU core is A LOT more powerful than CUDA core. – Migol Mar 30 '15 at 22:20
  • @startingBlender one more thing, to get a bit of performance, experiment with tile size in rendr options. – Migol Mar 30 '15 at 22:24
  • On my CPU, I have 8 cores each one has a speed of 2.67GHZ. But GPU has 336 cores but I do not know what 's their speed? What do you mean size in render options (size of what?). If I fix a low samples, I will have a lot of noise. – BetterEnglish Mar 30 '15 at 22:42
  • What kind of scene are you trying to render? 66 frames might be pretty good.. – gandalf3 Mar 31 '15 at 03:05
  • @gandalf3, here is my work .blend http://www.pasteall.org/blend/35315 . Can you try it on your computer and tell me about the result. – BetterEnglish Mar 31 '15 at 03:12

0 Answers0