Looking at the official spec sheet the GT 520 will have 48 CUDA processing cores, an 810MHz core clock speed, a 1620MHz shader speed, 1GB of 900MHz DDR3 memory, and a 64-bit memory interface providing a total bandwidth of just 14.4GB/s. The card features a low-profile design and a single-slot cooler that in all require only 29W of power. Like other Nvidia GeForce 500 series cards, the GT 520 will also support the company's PhysX and 3D Vision technologies.
Curiously, according to Nvidia's own performance charts, the card will be quite a bit slower that the $60 GeForce GT 430 and more on par with the old GT 220 and even the GeForce 9500 GT that was launched almost three years ago. Basically the improvement is in the power consumption front and smaller footprint.
The GeForce GT 520 is available now from Nvidia's add-in-board partners, which may make some tweaks to Nvidia's standard design like offering passive cooling. The card will also show up in pre-built systems from major manufacturers.