RAM Preview on Render. . .

WayneM wrote on 3/9/2015, 11:54 PM

I'm doing some benchmarks before upgrading my video card. Currently using ASUS P8 Z68-V-Pro MoBo's on-board Intel 3000 chipset. . .yes kinda stoneage. Obviously no GPU is available to enable. Windows 7 Pro 64-bit, 16 GB of DDR3 RAM, > 15 TB SATA 3 WD Black Caviar across 3 drives.

So I am rendering that project Sony put out with the Press Release for VP11, the one minute of views of the Red Mercedes.

I know that setting RAM Preview Memory in the Preferences to 0 can benefit some performance situations. I have .

In a series of tests, clean boots and all that good stuff, I rendered the project with all the setup as was documented for Sony's original tests. With RAM Preview Memory set to 1000, 2000, 5000, even 10000 I got (don't laugh too hard here) a render time of 4:38 to 4:44. With RAM Preview Memory set to 0 (zero) I get a render time of 7:33 to 7:35! Not what I would have expected.

With no GPU the CPU (Intel Core i7-2600K 3.4 GHz) is doing all the work.

Do the numbers make sense? Again, this is only a 'before' benchmark to see what I gain with the new card.

Thanks,

Wayne

Comments

astar wrote on 3/10/2015, 3:59 AM

Yeah that render preview thing is really old info. It might be relevant for VP11 if you are having crashing problems working with GPU enabled. With CPU only mode, preview ram at the default, or more if you use shift-B a frequently is best. I ran into your same conclusion back in 2010 or 11.

You do have AVX and Quicksync on that 2600k, does the Sony AVC/.mp4 have an option for quick sync under Encode mode? Do a couple tests with Quick sync enabled and Auto.

Run "Winsat mem" from an admin command line. Memory bandwidth should be 12GB - 20GB/s for a z68, if its lower than 12GB/s you might need faster memory to optimize.

If you get a discreet GPU, I would look at 5770, 7970, or 290x. Make sure USB 3.0 Turbo is off under bios, and that the x16 PCIe 2.0 slot is running x16 and not x8 with GPU-z. On my gigabyte MB, USB turbo mode caused the X16 slot to run at x8. PCIe 2.0 x16 is only about 6GB/s, halving that to x8 is pretty shy for a GPU with PCIe 3.0 interface. If you have PCIe add on cards make sure they are not installed in one of the x16 looking slots. If you crash a lot with GPU enabled under VP11, try converting all project media to XDCAM-ex, and see if that helps.

megabit wrote on 3/10/2015, 6:29 AM

The benefit of zero RAM buffer only shows in preview, especially full screen on Windows Secondary monitor (I'm getting full fps at Full/Best most of the time, when with RAM Preview at the default value of 200 MB can introduce a significant drop in preview fps).

For rendering, 200 or more will be much faster than 0 MB of the RAM Preview buffer. Sounds counterintuitive, but these are hard facts.

Piotr

OldSmoke wrote on 3/10/2015, 9:51 AM

Sorry, but there are no hard facts in this matter at all. What works on one system doesn't on another. Any deviation from the default 200 will slow down preview and rendering on my system.

A-Scott wrote on 3/10/2015, 12:17 PM

Preview RAM settings have been a black art for many years now. Strangely, setting it to 0 appears to really slow down renders even though it shouldn't matter.

I haven't tested the latest version 13, but I did it with my previous SVP 9 using the render test that gets posted here from time to time. With preview RAM set to 0, Vegas wasn't using much CPU for the render. With preview RAM set to 1 (yes, just *1*) Vegas nailed all 4 cores at about 100%.

As far as fine tuning your preview RAM setting, you'll just have to find out what works best for your system. However, the preview RAM=0 thing seems like a glitch to me.

rmack350 wrote on 3/10/2015, 2:59 PM

I think setting RAM Preview to zero really only solved some very specific problems when certain codecs were involved. As everyone else is saying, just test it. If it helps then use it but it's not a universal solution to all problems.

Vegas seems to do a couple of things with RAM that's been set aside for preview caching. First of all it caches uncompressed frames at whatever quality your preview window is set to, but it also seems to work as scratch space, probably when it's rendering anything with interframe comprerssion like AVC.

As for setting a RAM Preview at 10000... most of the RAM allocated to this is going to be unavailable to your render job. You really only need "just enough" allocated, then the rest can be used for the actual render.

WayneM wrote on 3/10/2015, 7:27 PM

"You do have AVX and Quicksync on that 2600k, does the Sony AVC/.mp4 have an option for quick sync under Encode mode? Do a couple tests with Quick sync enabled and Auto."

I'd never been aware there was any such functionality in the on-Mo-Bo video chipset. Never thought to look for it, but I did now. Didn't notice it in the feature set some 3 years ago. THANKS!

Looked for the settings and didn't see the Customize Template feature until I saw there were more controls when I scrolled the window down!

I found the Encode Mode option and it 'sees' Quick Sync. I tested all the options and Auto tested best. It did the render in 2:52. Best time with MainConcept AVC was 4:41.

For rendering to DVDs or for Internet HD is there any advantage of MC over Sony rendering?

Of course I get to start all over when the new ASUS card shows up in a few days :-)

Thanks again!

Wayne