Desktop form factor graphics cards packing mobile Nvidia GPUs appear to be readily available in China. Twitter's I_Leak_VN spotted multiple RTX 30 series designs available on China's Taobao online market place, and shared mining performance tables featuring these unofficial products. VideoCardz picked up on this story and unearthed an image which appears to show scores of these graphics cards being prepared for shipping.
From the Taobao listing images, the Nvidia GeForce RTX 3070 mobile GPU packing desktop graphics card appears to be the most popular of these unofficial mobile / desktop mashup products available now. They are priced at around 3,800 Yuan on average, which makes them roughly $560 as of this writing.
The asking price isn't exactly a bargain for the gaming power that an RTX 3070M offers. In the US you can buy a proper desktop RTX 3070 for around $600. If you have pondered over RTX 30 laptops and desktops you will also be well aware that the mobile and desktop GPUs aren't created equal. See this table for comparison:
| GeForce | RTX 3070 Mobile | RTX 3070 |
|---|---|---|
| GPU | GA104 | GA104 |
| Nvidia CUDA Cores | 5,120 | 5,888 |
| Boost Clock | 1.56 GHz | 1.73 GHz |
| Memory Size | 8 GB GDDR6 | 8 GB GDDR6 |
| Memory Clock | 1.75 GHz | 1.75 GHz |
| TDP | ~115W | 220W |
The most crucial differences between the two graphics solutions tabulated above is that the mobile version has its CUDA cores and GPU clock speeds pruned back significantly. Moreover, it runs with a lot less power on tap. The ~115W TDP quoted for the mobile GPU was how it was usually configured in the tight confines of a laptop. The Chinese hybrid solutions are mostly configured with twin fan coolers and have higher TDPs (single 8-pin power connector on the card).
So, what is the use of an RTX 3070M desktop graphics card if it isn't much cheaper, its content creator and gaming performance isn't going to be as good as the original desktop model, and the brand/build quality is suspect? It all comes down to cryptomining performance. Nvidia's laptop GPUs don't have an LHR technologies holding them back from working at their full potential down the silicon mines.
If you buy a new GeForce RTX 3070 graphics card from one of the big brands today, it will feature LHR technology, paring back ETH mining performance to about 30 MH/s. Nvidia recently struck back at a NiceHash workaround which effectively boosted the desktop RTX 3070 GPU ETH mining hash rate back to about 60 MH/s. However, buyers of the RTX 3070M desktop graphics cards won't need to worry about this whack-a-mole game, as they aren't buying LHR GPUs, and these lower power alternatives purportedly achieve up to approximately 65 MH/s. They might be more power efficient while mining, too, which could reduce costs involved in mining.
This isn't the first time we have reported on the repurposing of RTX 30 series mobile GPUs for desktop mining cards. In March we noted that the RTX 3060 Mobile was proving to be a popular choice for this kind of gray market activity.
If you are purely into PC gaming and content creation it is probably best to avoid these mashup mobile / desktop products. Desktop GPU pricing is slowly dropping to a more reasonable place. And with 'the merge' of Ethereum expected to actually happen in August, and next gen GPUs galloping along in Q3 and Q4, there will hopefully be plenty of nice GPU bargains over the summer.
