Should I get the GTX 580 My current specs are Graphics card ATI Radeon HD 4350 RAM 8GB CPU 750GB Now down to 340-400GB 64-bit operating system Windows 7 Home Premium Intel R Core TM?

Upgrading to the GTX 580 would provide a significant boost in graphics performance compared to your current ATI Radeon HD 4350, especially for gaming and demanding applications. However, ensure your power supply can handle the GTX 580's requirements and that your CPU won't bottleneck performance. Given your 8GB of RAM, you should be in a decent position, but consider whether your overall system can support the upgrade effectively. If you're looking for better performance and can meet the requirements, it could be a worthwhile investment.