OCC has published a review on the Asus GT240 1GB
A quote from the article:
>> Asus GT240 1GB Review
I am amazed by how far the ASUS GT 240 was willing to overclock! All testing was completely stable at the speeds 650 MHz core, 1745 MHz Shader, and 1850 MHz memory, equating to approximate gains of 18%, 30%, and 9% respectively. I managed to hit the wall for MSI Afterburner and other overclocking software for shader speed, while the core and memory were at their own inherent speed limitations. At stock idle, the GPU core was running at low to mid 20's 0C and load overclocked somewhere in the mid to high 40's depending on the test.
>> Asus GT240 1GB Review