Nvidia Slowed RTX 4090 GPU By 11 Percent, To Make It 100 Percent Legal For Export In China

Nvidia has throttled the performance of its GeForce RTX 4090 GPU by roughly 11%, allowing it to comply with U.S. sanctions and be sold in China. The Register reports: Dubbed the RTX 4090D, the device appeared on Nvidia's Chinese-market website Thursday and boasts performance roughly 10.94 percent lower than the model Nvidia announced in late 2022. This shows up in the form of lower core count, 14,592 CUDA cores versus 16,384 on versions sold outside of China. Nvidia also told The Register today the card's tensor core count has also been been cut down by a similar margin from 512 to 456 on the 4090D variant. Beyond this the card is largely unchanged, with peak clock speeds rated at 2.52 GHz, 24 GB of GDDR6x memory, and a fat 384-bit memory bus.

As we reported at the time, the RTX 4090 was the only consumer graphics card barred from sale in the Middle Kingdom following the October publication of the Biden Administration's most restrictive set of export controls. The problem was the card narrowly exceeded the performance limits on consumer cards with a total processing performance (TPP) of more than 4,800. That number is calculated by doubling the max number of dense tera-operations per second -- floating point or integer -- and multiplying by the bit length of the operation.

The original 4090 clocked a TPP of 5,285 performance, which meant Nvidia needed a US government-issued license to sell the popular gaming card in China. Note, consumer cards aren't subject to the performance density metric that restricts the sale of much less powerful datacenter cards like the Nvidia L4. As it happens, cutting performance by 10.94 percent is enough to bring the card under the metrics that trigger the requirement for the USA's Bureau of Industry and Security (BIS) to consider an export license. Nvidia notes that the 4090D can be overclocked by end users, effectively allowing customers to recover some performance lost by the lower core count. 'In 4K gaming with ray tracing and deep-learning super sampling (DLSS), the GeForce RTX 4090D is about five percent slower than the GeForce RTX 4090 and it operates like every other GeForce GPU, which can be overclocked by end users,' an Nvidia spokesperson said in an email.

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