This is a bit more complicated issue. Performance on GPU is not only depends on number of tiles, but also on particular size of tile. Making tiles size aligned to 16 pixels made much sense when i was doing tests during Mango. SO i could think using tile size of 1024x1024 could end up in faster render than using single tile for HD frame.<div>
<br></div><div>Also, as Daniel already mentioned, you could easier run out of memory with single tile and to make it more control over performance in such cases pixel-based tile size makes more sense.</div><div><br></div>
<div>If you want to force single tile being used always, why don't set tile size to 10K by 10K pixels -- it'll be clamped to actual image internally in render engine :)</div><div class="gmail_extra"><br><br><div class="gmail_quote">
On Thu, Nov 8, 2012 at 6:37 AM, Daniel Salazar - 3Developer.com <span dir="ltr"><<a href="mailto:zanqdo@gmail.com" target="_blank">zanqdo@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Speed is only half of the issue here. An HD (or higher) render will take a lot of memory and can very well crash your GPU rendering if not using tiles. What works for a couple models is not what works for a complete scene!<div>
<br clear="all">Daniel Salazar<br><a href="http://patazstudio.com" target="_blank">patazstudio.com</a><div><div class="h5"><br>
<br><br><div class="gmail_quote">On Wed, Nov 7, 2012 at 6:15 PM, Cal McGaugh <span dir="ltr"><<a href="mailto:cal@cal3d.com" target="_blank">cal@cal3d.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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Hi Adriano,
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very interesting..........no wonder I'm seeing longer renders with 2.64 vs 2.63.
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Will do more tests with different versions. Just got a new (used) Zotac GTX580
<br>and will test different tile settings.
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Thanks,
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Cal
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<br>On November 7, 2012 at 7:02 PM Adriano Oliveira <<a href="mailto:adriano.ufrb@gmail.com" target="_blank">adriano.ufrb@gmail.com</a>> wrote:
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<p style="margin-bottom:0.0001pt"><span style="font-size:12pt;font-family:Arial,sans-serif">Hi,</span></p>
<p style="margin-bottom:0.0001pt"><span style="font-family:Arial,sans-serif;font-size:12pt">Subdividing render image in tiles has very inconsistent behavior in CPU and GPU: more tiles are good for CPU, BUT less are better for GPU.</span></p>
<p style="margin-bottom:0.0001pt"><span style="font-family:Arial,sans-serif;font-size:12pt">With my i7, 8x8 is ok. With my GTX 560 Ti, 1x1 is the best. With another dual GTX 590 system, I've found 3x3 to be fastest...</span></p>
<p style="margin-bottom:0.0001pt"><span style="font-family:Arial,sans-serif;font-size:12pt">Problem: with 8x8 as default, non-advised GPU users are experiencing longer render times.</span></p>
<p style="margin-bottom:0.0001pt"><span style="font-family:Arial,sans-serif;font-size:12pt">In last builds, tiles became pixel based, what is not good for GPU users, as long as we should now set it up for equal image size and this can change a lot for preview. And as strange as it gets, I’ve found that tile size of 1920x1080 is fast even for a 960x540 render…</span></p>
<p style="margin-bottom:0.0001pt"><span style="font-size:12pt;font-family:Arial,sans-serif"> </span></p>
<p style="margin-bottom:0.0001pt"><span style="font-size:12pt;font-family:Arial,sans-serif">I think this is getting messy.</span></p>
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Adriano A. Oliveira
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div><span style="color:rgb(102,102,102)">With best regards, Sergey Sharybin</span></div><br>
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