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**pseudonym** · (This post was last modified: 07-21-2012, 01:23 AM by pseudonym.)

I made a new version which shows how the issue manifests as you approach 0.5. It looks like newer ATI cards fail when the title bar reads 511/1024.

Press A and Z to move closer to 0.5 and 0. (Just try it and you'll understand. NVidia users still probably never fail.)

.exe

atifail.exe (Size: 18 KB / Downloads: 473)

andutrache · 07-21-2012, 01:31 AM

ATI 6870
Catalyst 12.6
From 511/1024 FAIL

willkuer · 07-21-2012, 01:31 AM

(07-21-2012, 01:19 AM)pseudonym Wrote: (Just try it and you'll understand. NVidia users still probably never fail.)

actually:
starting at 33554431/67108864 to the end
I get a 'fail'...

Geforce 8600M GS

rounding error?

**pseudonym** · (This post was last modified: 07-21-2012, 01:43 AM by pseudonym.)

33554431/67108864 wasn't meant to be allowed (single precision floats run out of bits at that point), I forgot that I removed the upper limit temporary. Attachment updated already, I hoped nobody would see it first.

**gigaherz** · 07-21-2012, 01:44 AM

For reference, the integrated GPU in my Sandy Bridge laptop fails on 127/256 already, only works up to 63/128. So... they are sacrificing THAT much precision and it's still horribly slow? XD