In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce 8600 GT 512MB GDDR3 are very slightly better than the Nvidia GeForce GT 620 Zotac Synergy 2GB Edition.

The GT 620 has a 160 MHz higher core clock speed and the same number of Texture Mapping Units as the 8600 GT. This results in the GT 620 providing 2.6 GTexel/s better texturing performance. This still holds weight but shader performance is generally more relevant, particularly since both of these GPUs support at least DirectX 10.

The GT 620 has a 160 MHz higher core clock speed than the 8600 GT, but the 8600 GT has 4 more Render Output Units than the GT 620. As a result, the 8600 GT exhibits a 1.5 GPixel/s better Pixel Fill Rate than the GT 620. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

The GT 620 was released over three years more recently than the 8600 GT, and so the GT 620 is likely to have far better driver support, meaning it will be much more optimized and ultimately superior to the 8600 GT when running the latest games.

The GT 620 has 1536 MB more video memory than the 8600 GT, so is likely to be much better at displaying game textures at higher resolutions. However, overall, the 8600 GT has superior memory performance.

The 8600 GT has 13.9 GB/sec greater memory bandwidth than the GT 620, which means that the memory performance of the 8600 GT is slightly better than the GT 620.

The GeForce GT 620 Zotac Synergy 2GB Edition has 96 Shader Processing Units and the GeForce 8600 GT 512MB GDDR3 has 32. However, the actual shader performance of the GT 620 is 134 and the actual shader performance of the 8600 GT is 43. The GT 620 having 91 better shader performance is not particularly notable, as altogether the 8600 GT performs better when taking into account other relevant data.

The GT 620 transistor size technology is 40 nm (nanometers) smaller than the 8600 GT. This means that the GT 620 is expected to run much cooler and achieve higher clock frequencies than the 8600 GT. While they exhibit similar graphical performance, the GT 620 should consume less power than the 8600 GT.

The GeForce GT 620 Zotac Synergy 2GB Edition requires 49 Watts to run and the GeForce 8600 GT 512MB GDDR3 requires 46 Watts. We would recommend a PSU with at least 300 Watts for the GT 620 and a PSU with at least 350 Watts for the 8600 GT. The GT 620 requires 3 Watts more than the 8600 GT to run. The difference is not significant enough for the GT 620 to have a noticeably larger impact on your yearly electricity bills than the 8600 GT.