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Tuesday, November 1, 2022

Nvidia GeForce RTX 3090 Ti Specifications

Last generation's ultimate GPU, the GeForce RTX 3090 Ti only launched in late March of 2022 — to see how performance stacks up, check our extensive list of GPU benchmarks and the best graphics cards. It was also a product of the cryptocurrency era, which meant GPU supply still hadn't caught up with demand and Nvidia felt it could get away with an exorbitant launch price of $1,999.

A few months later, demand plummeted and Nvidia dropped the 3090 Ti Founders Edition price to $1,099 at Best Buy, which in turn pissed off some of its add-in card (AIC) partners like EVGA, who ultimately decided to stop making graphics cards altogether — and who probably has a shload of RTX 30-series parts still in stock that it's trying to offload as quickly as possible. But don't feel bad for EVGA or the other AIC partners, because they made out like bandits throughout all of 2020 and 2021!

As far as the RTX 3090 Ti specifications, this is the fully enabled GA102 chip, the top of the Ampere architecture. It's interesting to compare this chip with the RTX 4090 specifications, to see how much things have changed. Note that the die size on GA102 is slightly larger than the new AD102, and yet AD102 packs nearly three times as many transistors. That's all thanks to the move from Samsung 8N ("8nm Nvidia") that was really just a tweaked version of Samsung's 10nm process, over to TSMC 4N ("4nm Nvidia") that's a tweaked variant of TSMC's 5nm N5 process. Obviously, the latter offers significantly higher transistor density.

Nvidia GeForce RTX 3090 Ti Specifications
Process TechnologySamsung 8N
Transistors (Billion)28.3
Die size (mm^2)628.4
Streaming Multiprocessors84
GPU Cores (Shaders)10752
Tensor Cores336
RT Cores84
Boost Clock (MHz)1860
VRAM Speed (Gbps)21
VRAM Bus Width384
L2 Cache6
Render Outputs112
Texture Mapping Units336
FP32 TFLOPS (Single-Precision)40.0
FP16 TFLOPS (Sparsity)160 (320)
Bandwidth (GB/s)1008
Total Board Power (Watts)450
Launch DateMarch 29, 2022
Launch Price$1,999

The maxed out Ampere chip in the RTX 3090 Ti has 84 SMs and 10,752 CUDA cores, along with 336 Tensor cores. Combined with clocks, the 3090 Ti offers up to 40 teraflops of FP32, or 320 teraflops of FP16. Unlike the new Ada Lovelace Tensor cores, there's no FP8 support, which means theoretical compute for AI workloads is about one-fourth of what the RTX 4090 can offer — not accounting for other architectural differences.

In order to try and differentiate the RTX 3090 Ti from the existing RTX 3090, Nvidia also bumped up the TBP (Total Board Power) by 100W, which allows the GPU to sustain substantially higher clocks compared to the 3090. It also allowed Nvidia and its partners a chance to test the waters for a 450W graphics card and pave the way for the 4090. Ironically, where the 12-pin and 16-pin adapters that came with RTX 3090 Ti cards all seemed to work fine, the new 4090 16-pin adapters appear to have used poor soldering that's prone to cracking and can cause a fire hazard. Oops.

The RTX 3090 Ti also uses new 2GB (16Gb) 21 Gbps GDDR6X memory, where the original RTX 3090 used 1GB (8Gb) 21 Gbps chips — this is the same 21 Gbps GDDR6X memory as the new RTX 4090, which means they have the same memory bandwidth. However, Ada cards have significantly larger L2 caches — 12X larger for the 4090 versus 3090 Ti — and that in turn means effective memory bandwidth is substantially improved. If the L2 cache hit rate on a 4090 for example is 60% at 4K, that means only 40% of memory accesses actually hit the GDDR6X memory, which means 2.5X more effective bandwidth. Nvidia has not detailed the actual L2 hit rates, which will vary by workload, but 50–70 percent seems likely.

At present, RTX 3090 Ti cards can be found starting at around $1,290 on Amazon. Considering the pending arrival of the GeForce RTX 4080, I can't help but think the RTX 3090 Ti represents a terrible value at this time — or actually any time since launch. At first it was far too expensive, but by the time Nvidia slashed prices and forced the AIC partners to do the same, Ada Lovelace was right around the corner and there was no reason to even consider buying a 3090 Ti. It's generally the fastest graphics card from the Nvidia Ampere and AMD RDNA 2 era — at least at 4K and in professional workloads — but it arrived too late, provided too little of a performance uplift (only about 10% faster than the 3090), and also required substantially more power.

If you're even thinking about buying an RTX 3090 Ti card, used or otherwise, you should instead look at the RTX 4090. Well, unless you can pick one up for under $700. And don't forget that RTX 4070 is also on the way.

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