NOTE: This is my very first blog :P
The Radeon R5 230 is the direct competitor of the GeForce GT 610 - but which GPU is the fastest?
The Radeon R5 GPUs (220 and 230) belong to the entry-level Radeon R-200 GPUs (mid-end: R7, high-end: R9) and the GeForce GT 610 is the weakest GPU of the GeForce 600 Series. Both GPUs use very little power (only 15-30 watts), which make them excellent GPUs for a HTPC setup. Many low-end GPUs have "passive" and "active" versions. Passive cooling means that the GPU does NOT have any fan cooling: the entire GPU is cooled by a heatsink. While passive cooling is preferable for HTPC (due to very low noise levels), it also causes more heat production, as heatsinks are often inadequate for cooling. Active cooling means that the GPU has any form of fan cooling. This produces much more noise than passive cooling, but it keeps the temperatures noticeably lower. Active cooling also makes overclocking easier.
Now, we're comparing the technical specifications of both GPUs directly (by reference model!).
The GeForce GT 610 has a 810MHz core speed compared to just 625MHz on the Radeon R5 230 (30% better GPU clock). This does not really matter, as low-end GPUs aren't designed for overclocking anyway.
The GeForce GT 610 and Radeon R5 230 both have 1GB of slow DDR3 memory (reference model!). They both access the frame buffer (= VRAM) through a craptastic 64-bit memory bus. However, the GeForce GT 610 has a 367MHz faster memory clock than the Radeon R5 230 (900 vs. 533MHz = 69% better memory clock). This allows the GeForce GT 610 to render textures faster. A higher memory clock also increases the memory bandwidth slightly. The GeForce GT 610 has a memory bandwidth of 14.4GB/sec, compared to 8.5GB/sec of the Radeon R5 230 (70% better memory bandwidth). Both GPUs have a terrible memory bandwidth - even the reference model of the GeForce 6600 GT (2004) has a higher memory bandwidth (16GB/sec).
The Radeon R5 230 has a very high amount of shader processing units for a low-end GPU: 160! Compared to the GeForce GT 610, the Radeon R5 230 has 333% more shader processing units (160 vs. 48). However, the actual shader performance of the Radeon R5 230 is a mediocre 50, compared to 78 of the GeForce GT 610. As a result, the GeForce GT 610 has 56% faster shader performance. Both GPUs have 8 TMUs (Texture Mapping Units) and 4 ROUs (Render Output Units). The texture and pixel rate of the GeForce GT 610 are 6.5 GTexel/s and 3.2 GPixel/s compared to 5.0 and 2.5 on the Radeon R5 230, respectively. This means that the GeForce GT 610 has a 30% higher texture rate and 28% higher pixel rate.
Both GPUs support DirectX 11.0 (hardware default), Pixel Shader 5.0, OpenGL 4.x (GeForce GT 610 supports OpenGL 4.2 while Radeon R5 230 only supports 4.1), a maximum resolution support of just 2560x1600, and 1x VGA + 1x DVI + 1x HDMI (this depends on the model: for example, some may have 2x HDMI, 2x DVI, and so on).
And finally, we're comparing the power usage of both GPUs. The Radeon R5 230 has a maximum power usage of 19 Watts, while the GeForce GT 610 requires 29 Watts. In conclusion, the Radeon R5 230 uses 35% less power. Again, as both GPUs have a very low power consumption, this doesn't matter at all.
As we can see, the GeForce GT 610 is quite better than the Radeon R5 230. But still, do NOT purchase them if you want to play games either way. Even worse, non-demanding games like CS:GO require to be run on medium settings (no AA, no shadow, no texture filtering) at a resolution of 1024x768 (ancient for today's gaming standards), if you want to achieve 60+ fps.
Since integrated graphics becomes better over time, budget cards like the GeForce 210/GT 610 and Radeon HD 6450/R5 230 become more and more useless. Integrated graphics also save even more power. In my opinion, using integrated graphics for a basic HTPC/barebone setup is more viable than purchasing a dedicated HTPC-designed GPU instead. If you are planning on buying one of these GPUs for a budget/barebone builld, only do so when your CPU doesn't have integrated graphics.
Thanks for reading my very first blog :)
TL;DR - GeForce GT 610 is better and cheaper ($39 vs. $45) than Radeon R5 230, both are bad for gaming anyway, and IGP is nowadays better for HTPC/budget PCs.