\[ \boxed { 2\, \left ( {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) \right ) y \left ( x \right ) - \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}-8\, \left ( y \left ( x \right ) \right ) ^{3}=0} \]
Mathematica: cpu = 0.483061 (sec), leaf count = 127 \[ \left \{\left \{y(x)\to -\frac {1}{2} i \sqrt {c_1} \text {ns}\left (\left .\frac {1}{2} \left (-(-1)^{3/4} \sqrt {2} \sqrt [4]{c_1} x-(-1)^{3/4} \sqrt {2} \sqrt [4]{c_1} c_2\right )\right |-1\right ){}^2\right \},\left \{y(x)\to -\frac {1}{2} i \sqrt {c_1} \text {ns}\left (\left .\frac {1}{2} \left ((-1)^{3/4} \sqrt {2} \sqrt [4]{c_1} x+(-1)^{3/4} \sqrt {2} \sqrt [4]{c_1} c_2\right )\right |-1\right ){}^2\right \}\right \} \]
Maple: cpu = 1.669 (sec), leaf count = 53 \[ \left \{ \int ^{y \left ( x \right ) }\!{\frac {1}{\sqrt {4\,{{\it \_a}} ^{3}+{\it \_C1}\,{\it \_a}}}}{d{\it \_a}}-x-{\it \_C2}=0,\int ^{y \left ( x \right ) }\!-{\frac {1}{\sqrt {4\,{{\it \_a}}^{3}+{\it \_C1} \,{\it \_a}}}}{d{\it \_a}}-x-{\it \_C2}=0 \right \} \]