Pretty sure it has to do with benchmarks and the cut-throat competitive environment GPU-manufacturers exist in where you cut all corners to proclaim &quot;We&#x27;re the fastest!&quot;<p>Not zeroing a buffer cuts a big constant out of overhead. If you know which of the benchmarks will fail if you don&#x27;t zero the buffer, you code in an &quot;exception&quot; so the benchmark doesn&#x27;t fail and other applications act wonky. This isn&#x27;t the &quot;first time&quot; nVidia has been caught doing this, see:<p><a href="http:&#x2F;&#x2F;www.geek.com&#x2F;games&#x2F;is-nvidia-cheating-on-benchmarks-553389&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.geek.com&#x2F;games&#x2F;is-nvidia-cheating-on-benchmarks-5...</a>