Blower-style RTX 4090 48GB teardown reveals dual-sided memory configuration — PCB design echoes the RTX 3090

Since the US imposition of sanctions prohibiting the sale of high-performance GPUs to China, indigenous manufacturers have taken it upon themselves to mitigate these limitations by modifying existing solutions. One of the results of these modding endeavors is an RTX 4090 with 48GB of GDDR6X memory, which is now becoming commonplace among local circles. Russian YouTuber Мой Компьютер (My Computer) obtained a blower-style edition RTX 4090 48GB, later taking it apart to examine the PCB among other design features.

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Both the RTX 4090 and RTX 3090 Ti's PCBs carry 12 available memory slots, which equate to 24GB of VRAM with one 16Gb IC populating each slot, and that's not the configuration we're looking for. The base RTX 3090, on the other hand, offers 24 memory slots (12 on each side of the PCB), suggesting a modified version of it could be used as a foundation here. It's hard to be certain, however. Either way, the RTX 4090 48GB we're examining today features a board design that strongly resembles RTX 30 series PCBs.

Matching the cooler's design, the YouTuber links this card to Peladin, a Chinese mini-PC/GPU manufacturer. The reviewer asserts the GPU's PCB is well-designed, with robust VRMs, and the added memory on the backside is covered with high-quality thermal pads and a backplate to keep temperatures in check. Unlike workstation-grade RTX 6000/5880 Ada GPUs, which stick with GDDR6, this RTX 4090 is equipped with GDDR6X memory, which is faster but also runs hotter.

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Surprisingly, the GPU was recognized in Windows, and you can even use traditional GeForce drivers instead of relying on potentially risky third-party options. The YouTuber mentions a breach at Nvidia where hackers obtained internal tools, including MATS and MODS. Modders can employ these utilities to modify VRAM, disable non-working channels, and even flash new volumes on the GPU's firmware without violating any checksums or digital signatures.

The test bench used for the handful of benchmarks conducted featured the Ryzen 5 7600X3D, and 48GB of DDR5-6000 memory, on the Maxsun Challenger B650M motherboard. Under load, the GPU is quite loud, defined as "sounding like an airplane" at 65dB with fan speeds exceeding 5,000 RPM. That's one of the key drawbacks of blower-style coolers, but it was a necessary tradeoff to enable higher compatibility in servers. Even so, during a half-hour test in Superposition at 8K, the card maintained a relatively stable 2.7 GHz clock speed at 70 degrees Celsius with the memory at 86 degrees Celsius.

After extensively testing the GPU in synthetic benchmarks, LLMs, and games, the YouTuber revealed they were provided the GPU by XON, a local store specializing in workstations and servers. At the time of recording, the GPU was listed at $4,400 (370,000 Rubles). While expensive, this might still be one of the most affordable 48GB options on the market, at least until we see Nvidia's Blackwell workstation in action.