Author Topic: Apple iMac  (Read 3919 times)

ivanilmatto

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Apple iMac
« on: August 29, 2011, 12:02:27 am »
August 29, 2011, 12:02:27 am
Hello Everybody,
has anyone of you ever tried Lumion with an iMac (started as Widows with BootCamp)?
I saw some benchmarks about the video card mounted in new iMac 27" (Ati Radeon HD 6970M 2GB GDDR5) and they seem quite impressive. What do you think about? Could it be a good deal with Lumion?
At the moment I have a standard PC using two Nvidia 460 gtx in SLI; what would be the performance difference... more or less?

Ciao!
Paolo

Re: Apple iMac
« Reply #1 on: August 29, 2011, 10:42:32 am »
August 29, 2011, 10:42:32 am
Hi Paolo,
M-series cards will obviously never be as fast as "full-size" graphics cards.

Notebookcheck.net have carried out a series of benchmark tests, e.g. 3D Mark 11 etc, just click on the "Show comparison chart" options to compare this card to your 460s:
http://www.notebookcheck.net/AMD-Radeon-HD-6970M.43077.0.html

The performance in some benchmark tests seem pretty close to a single 460 GTX...

Also, the 6970M is a bit slower (11-21% depending on the benchmark) than my ATI Radeon HD 5850, and in my experience, fillrate tends to be a problem for cards in this price/performance range. The 'fill rate' describes the amount of pixels that a graphics card can render in a given amount of time. In other words, the higher the screen resolution, the lower your frame rate is going to be, so running complex scenes in Lumion in full screen (2560x1440) on the 27" iMac is going to be tricky, unless you're happy with lower star quality in the editor.

You can of course also run Lumion in lower resolutions (in a window), or reduce the Resolution slider in the Lumion settings menu, but that's not ideal if you're expecting better performance when upgrading to an iMac. For comparison, the ATI Radeon HD 5850 performs at 30-45 fps when I fly around the Alpine Dwelling demo scene in 3-star quality at 1920x1200 (in Build 7).

ivanilmatto

    Reputation: 2
Re: Apple iMac
« Reply #2 on: August 29, 2011, 11:49:08 am »
August 29, 2011, 11:49:08 am
Thanks for the reply... another question, just to understand more the way Lumion works: at the moment, Lumion uses SLI or not?  I remember I read somewhere (time ago) Lumion doesn't use SLI video card but only one card. Is this correct? this way if I move to an iMac system I won't gain but neither lose performance compared to my actual pc. Is this correct?

thanks,
Paolo

Re: Apple iMac
« Reply #3 on: August 29, 2011, 12:50:06 pm »
August 29, 2011, 12:50:06 pm
I remember I read somewhere (time ago) Lumion doesn't use SLI video card but only one card. Is this correct?

From one of Remko's posts:
Lumion can do SLI but the performance increase is not as big as I hoped. Why this is the case is a mystery because we follow the guidelines for SLI programming quite well. I guess we have to do more testing. It might be something very simple like a flag that has to be set when we create a texture or something like that.

ivanilmatto

    Reputation: 2
Re: Apple iMac
« Reply #4 on: August 29, 2011, 04:06:54 pm »
August 29, 2011, 04:06:54 pm
Thanks;
so at the moment using my geforce 460 gtx ora the video card provided qith the new iMac is pretty similar, doesn't it?

bye,
Paolo

Re: Apple iMac
« Reply #5 on: August 29, 2011, 05:20:44 pm »
August 29, 2011, 05:20:44 pm
If you run Lumion at the same resolution on 2 x GTX 460 or 1 x 6970M, the benchmarks seem to suggest that it might be a close race. However, Remko says that Lumion does run a little faster in SLI than on a single card, so the GTX 460 might have a slight edge in this example.