Performance issues

[liquidengine]

I have tried posting in the general discussion, however I am not allowed?!?! I have also unsuccessfully tried to get support for my question. SO apologies in advance if this is the wrong place to ask a question, but I have little choice.
I recently bought an iMac with a 640M Nvidia card after doing research on Otoy website gave it a rating of 3.0 https://developer.nvidia.com/cuda-gpus (one of the highest).
Octane is so slow it's un-useable. I have the simplest of scenes created in Blender (a cube and a ball).

I have looked for a solution to see where I could improve the performance, or some other reason. I sincerely hope my graphic card is not the issue, as I bought this mac specifically for Octane. I have used in the past with no issue on a much older machine.

Any advice would be much appreciated.

Thanks all.

[riggles]

It's possible that the 640M just isn't powerful enough. Octane really runs best on graphics cards with lots of CUDA cores. If you look at the 640M specs page, you'll see it has 384 CUDA cores. The 27" iMac of the same year with a 680MX card has almost 5x as many: 1536 cores. Unfortunately, NVIDIA giving them the same '3.0' score was quite misleading, as they do not have the same CUDA performance at all.

[liquidengine]

Surely it is the responsibility of Otoy/Octane to ensure any info they link to on their website is NOT misleading, or at least have a big disclaimer stating that the information is probably flawed.
£900 for a machine that cannot useably run Octane - Not happy.
Perhaps someone out there could point me in the direction to configure Octane so I can at least work, then leave things to render over night.
Any assistance appreciated.

Thanks.

[stratified]

Hi there,

Those numbers aren't scores. They are the compute capability of the card. It says what the card is "capable" of and it translates to the architecture of the card as well (tesla (1.x), fermi (2.x), kepler (3.x), maxwell (5.x)).

You can't buy any tesla's or fermi's anymore and you have great cards and rubbish cards for each compute capability. I guess your 640M card would be classified as a low end card. It's hard to get descent performance on a laptop with Octane. Most people here use desktops specially built for Octane.

cheers,
Thomas

[mib2berlin]

Hi, I am awfully sorry but the GT 640m is not powerful for GPU rendering.
The 3.0 meant Compute Capability, this has nothing to do with performance, it is a feature set.
"m" is for mobile device and you get only 50% performance as the GT 640 desktop card.
The GT 640 cost 70 €, it is a low end card.
In my opinion there are two ways:
Give iMac back and buy other system.
Buy cheap PC, put GTX 750/760 2-4GB in, run Windows or Linux and work remote from your iMac.

Cheers, mib.

[liquidengine]

When someone goes about investing in a piece of software, those responsible users check the hardware requirements... In your FAQ there is a link right at the top that say's ' you guessed it' - Hardware requirements.
You then go on to show us a little table where you state (and I quote) - 3.0 & 3.5 = NO LIMITATIONS.
There is no mention of the amount of cores required.
What I am now hearing is that contrary to what we (Otoy) state, some cards don't apply to these rules and, oh. best not run it on a laptop (I am using a 1 year old Apple iMac)
Some advice... At the top of you Hardware requirements, I think it might be sensible (and responsible to your new users) to state - This software will not work very well on laptops and the majority of Apple iMacs.

[liquidengine]

Hi, I am awfully sorry but the GT 640m is not powerful for GPU rendering.
The 3.0 meant Compute Capability, this has nothing to do with performance, it is a feature set.
"m" is for mobile device and you get only 50% performance as the GT 640 desktop card.
The GT 640 cost 70 €, it is a low end card.
In my opinion there are two ways:
Give iMac back and buy other system.
Buy cheap PC, put GTX 750/760 2-4GB in, run Windows or Linux and work remote from your iMac.

Cheers, mib.

Thanks. Appreciate your comments and time.

[stratified]

When someone goes about investing in a piece of software, those responsible users check the hardware requirements... In your FAQ there is a link right at the top that say's ' you guessed it' - Hardware requirements.
You then go on to show us a little table where you state (and I quote) - 3.0 & 3.5 = NO LIMITATIONS.
There is no mention of the amount of cores required.
What I am now hearing is that contrary to what we (Otoy) state, some cards don't apply to these rules and, oh. best not run it on a laptop (I am using a 1 year old Apple iMac)
Some advice... At the top of you Hardware requirements, I think it might be sensible (and responsible to your new users) to state - This software will not work very well on laptops and the majority of Apple iMacs.

That FAQ isn't misleading. There are indeed no limitations in Octane for 3.0 & 3.5. We don't state anywhere how fast it's supposed to work.

You can perfectly run Octane on your laptop and everything works. Not all GPUs are created equal. Otherwise NVIDIA would just sell 1 fits all card...

cheers,
Thomas

[glimpse]

..This software will not work very well on laptops and the majority of Apple iMacs.

liquidengine (& other mac lovers)..consider the fact that macs are not the most powerful computers on earth..- their focus is on asthetics & ease of use. - it doesn't matter from what standpoint You're going to look at it..it's the same. Take the pill & swallow it & start to think..

why do You even consider that nice computer (iMac) with Mobile parts to be fast? it's not the power tool..it's nice decoration. (I'm not MAC hater, do have some Apple devices, but hey..) diferent purpose that's all & noOne to blame here.

Any advice would be much appreciated.

The best option would be build a box dedicated for work..not a piece of decoration.

[prehabitat]

//.

I Have a dell laptop, running windows 8 with a GT650M 2gb. it shouldn't be MUCH more powerful than your iMac - and its quite usable. (although that said; I'm sure the gt640M in an apple is down-clocked further to reduce heat & power consumption)

I would also investigate alternative drivers/resolutions/etc. before I would rule it out... don't expect it to smoke an enthusiast / professional level card: but I would certainly expect it to be faster than CPU ray tracing - My laptop is faster by a large factor.