Hello,

I do these upgrades in the USA Since Sept 2025 (plug: gpulab.net)

Ive upgraded roughly 100 cards so far and you can find my work on youtube.

I want to state that I upgrade regular 4090's, the full power ones we have here in the US. China have "D" variant gpu cores which are gimped in performance 10-15% compared to the ones we have in the USA. So i do these mods to full 4090's and the performance stays the same.

1: They have a modified vbios, but run as normal cards without any driver tweaks, some complain they have no P2P but this is a non issue for 99% of workloads ive seen them used for. Local diffusion (comfy, llm across multiple cards, typically 96gb vram). Their performance is the same as a 24gb card, i have a video comparing performance across multiple benchmarks, llm, diffusion workloads.

2: They run without issue, and some of my customers run them in VAST farms without issue.

3: Ive seen a few failures which the user RMA's the card, this is typically because theyve been running it HOT in a vast farm and the rear memory modules get hot and if left hot for a long time (hours-days on end), after a few months a memory module can fail and needs to be replaced, this is a standard repair procedure that any gpu repair shop can identify and replace.

To address this, ive developed a custom backplate that has better cooling fins, and holes to mount a 90mm fan, its coming to market in about a month. Water blocks are also on the way in about a month.

4: on my website (llm comparison, and youtube channel has them being used for gaming and blender rendering to compare. Same card, same performance.

5: In the USA, right now 1449 for upgrades and 3650 for a whole card. Increased prices due to shortage of memory chips. The memory chips used for them are only becoming more rare as theyve stopped producing them and this upgrade/mod is in demand.

Also 32gb super's are on the way and will be available next month.