Modder Builds Working RTX 3070 Ti 16GB GDDR6 on RTX 3070 Board [2026]

By Indie Kings | September 19, 2026

Updated September 19, 2026: Brazilian modder Fmklab has built a working GeForce RTX 3070 Ti with 16GB GDDR6, per VideoCardz. The project swaps the retail card's GDDR6X for GDDR6 on a modified RTX 3070 board and passes MATS memory testing with full 16GB allocation.

Modded GeForce RTX 3070 Ti PCB with 16GB GDDR6 chips installed and GPU-Z showing 16GB detection

Image: The modified RTX 3070 Ti with 16GB GDDR6 installed and GPU-Z detection. Credit: Fmklab via VideoCardz.

What Fmklab built

Per VideoCardz on September 8, 2026, Brazilian creator Fmklab built a functional RTX 3070 Ti with 16GB of GDDR6. This is not a simple capacity doubling mod on a stock 3070 Ti board. The retail 3070 Ti uses GDDR6X at 19 Gbps, while this build uses conventional GDDR6.

GPU-Z reads the result as an RTX 3070 Ti with 16GB GDDR6, and the creator says workloads can allocate the full 16GB. The card boots into Windows and completes normal 3D workloads, per the coverage.

VideoCardz notes the card is not based on a stock RTX 3070 Ti PCB. It uses an ASUS TUF RTX 3070 board that already supports GDDR6, with a transplanted RTX 3070 Ti GPU and modified firmware and memory straps. Original HC14 chips were replaced with higher-capacity HC16 chips.

How the 16GB GDDR6 mod works

The mod has three major steps: board selection, GPU transplant, and memory and strap changes. The donor board is an RTX 3070 platform that is designed for GDDR6 signalling and power delivery, unlike the GDDR6X path on retail 3070 Ti boards.

The RTX 3070 Ti GPU is then mounted to that board. Firmware and straps are modified to map the larger capacity and to train the GDDR6 correctly. Fmklab documents memory reballing and soldering, strap edits, and firmware analysis tied to a Late Engineering Sample path that previously hinted at GDDR6.

Verification shown includes MATS memory testing passing, GPU-Z detection, and a UNIGINE Superposition run as proof of 3D functionality. VideoCardz says more gaming benchmarks and comparisons are planned by the creator.

Config	Memory	Bandwidth	Status
Retail RTX 3070 Ti June 2021	8GB GDDR6X 19 Gbps	608 GB/s	Official launch spec
Prototype RTX 3070 Ti 16GB December 2022	16GB GDDR6	512 GB/s per GPU-Z surface by VideoCardz	NVIDIA prototype, not released
Fmklab mod September 2026	16GB GDDR6 HC16 on RTX 3070 board	GDDR6 rate, board dependent	Working mod, GDDR6, Windows and MATS verified

History of the unreleased 16GB 3070 Ti

The 16GB idea first surfaced in September 2020 when a Lenovo Legion T7 spec sheet listed an RTX 3070 Ti 16GB GDDR6. Per VideoCardz, Lenovo later removed the listing and NVIDIA eventually launched the 3070 Ti in June 2021 with 8GB GDDR6X.

In late 2021 and early 2022, ASUS and Gigabyte registered RTX 3070 Ti 16GB models at 19 Gbps GDDR6X that never reached market. Then in December 2022 a real NVIDIA RTX 3070 Ti 16GB prototype surfaced. Per VideoCardz, GPU-Z on that prototype showed GDDR6 at 512 GB/s rather than 608 GB/s GDDR6X.

Fmklab says he studied Late Engineering Sample firmware tied to that unusual GDDR6 path, which informed his current strap work. That explains why his mod is GDDR6, not GDDR6X, and why it aligns with the prototype's memory type.

How it performs and verifies

The coverage so far focuses on correctness, not gaming gains. The card passes MATS, which tests memory integrity, and boots Windows, per VideoCardz. Superposition provides a smoke test that the graphics pipeline works end to end.

Capacity is the win. Workloads that need more than 8GB, such as high-resolution textures or creative apps, can allocate the full 16GB. Bandwidth is lower than retail GDDR6X, so raw speed is not the point. The project is about proving a working 16GB GDDR6 path exists for this GPU.

Fmklab plans more game benchmarks. Until those appear, treat this as a working proof of concept with documented rework, not a recommended upgrade path.

Board: ASUS TUF RTX 3070 donor for GDDR6 support.
GPU: RTX 3070 Ti GPU transplanted with strap and firmware mods.
Memory: HC14 replaced with HC16 for 16GB GDDR6.
Proof: MATS pass, GPU-Z 16GB detection, Superposition run shown.

Should you try this mod

This is expert rework with hot-air reballing, strap editing, and firmware handling. It is not a vBIOS toggle or a simple cooler swap. You can destroy a card and a donor board if any step goes wrong.

Even if successful, you will have a one-off card with no official driver profile for this exact configuration. Fmklab's documentation is detailed, but replicating it requires tools and experience far beyond normal PC building.

For most gamers, a modern 12GB or 16GB retail GPU remains cheaper and safer. The value here is historical and technical: it shows the 16GB GDDR6 path NVIDIA prototyped could be made to work in the wild.

FAQ

Is this the first RTX 3070 Ti 16GB GDDR6 ever made?
No. Per VideoCardz, NVIDIA built at least one GDDR6 prototype in December 2022, but Fmklab says his is the first publicly documented working mod that reproduces that specific configuration.

Does it use GDDR6X?
No. This build uses GDDR6. Retail 3070 Ti uses GDDR6X, while both the 2022 prototype and this mod use GDDR6.

Does it have 608 GB/s bandwidth?
No. Per the prototype data relayed by VideoCardz, the GDDR6 path is around 512 GB/s, below the retail 608 GB/s GDDR6X rate.

Can games use the full 16GB?
Yes, per Fmklab via VideoCardz, workloads can allocate the full 16GB on the modified card.

Is it faster than a retail 3070 Ti in games?
Not necessarily. Extra VRAM helps in VRAM-heavy scenes, but lower bandwidth can offset gains. More benchmarks are planned.

Can I buy this card?
No retail version exists. This is a one-off mod. NVIDIA never released a 3070 Ti 16GB product.

Bottom Line

Fmklab's 16GB GDDR6 RTX 3070 Ti is a careful restoration of a cancelled NVIDIA path that first leaked in 2020 and surfaced as a prototype in 2022. It boots, it passes memory testing, and it exposes 16GB to software, per VideoCardz. As a replicable mod it is expert-only, but as a piece of hardware history it closes a long loop on a card many assumed would never exist.