RTX 4090 performance, thermals and power consumption

[Muhammed_Hamed]

Hello everyone,

I share my thoughts over the RTX 4090 performance, thermals and power consumption. It will be helpful for anyone planning on buying the new GPUs, I will update the thread with more testing once I receive my card next week. If you have questions let me know below

• The RTX 4090 performance exceeds expectations in all respects, GPU rendering, video encoding and gaming.
• The RTX 4090 is 125% faster than the 3090 in V-Ray's RTX Benchmark. The 4090 scores 5800 points in our RTX benchmark, while the RTX 3090 scores 2600 in the same test. In the Cuda Benchmark The RTX 4090 is 116% faster than the RTX 3090, the RTX 4090 scores 4350 points, and the 3090 scores around 2000
• The embargo on the 4090 Benchmarks are lifted yesterday for the Founders Edition cards, everything on the web now is specific to Founder's Edition cards. Today there will be more benchmarks on the 3rd party cards from Asus, MSI, Gigabyte and others.

This is important as many of our users buy 3rd party cards, usually FE cards are out of stock within weeks of release and we are only left with 3rd party cards. 3rd party cards use custom PCB and improved cooling, these cards use higher TDP than Founder Edition, so they will perform better out of box, they run at higher frequency and use aggressive voltages as they can handle more heat. Expect up to 10% faster performance in GPU rendering with the high end 3rd party 4090s. Namely The ROG Strix 4090 and MSI SuprimX 4090, these 2 GPUs are really good if you plan on buying 4090s

Techgage tested the RTX 4090 FE with V-Ray GPU, please take a look at their testing and conclusions here

• Power consumption

The 4090 Founder Edition runs below 400 Watts in games and GPU rendering, only a handful of synthetic benchmarks will push the 4090 to 450 Watts(which is the default TDP). So the 4090 is more efficient than the 3090Ti in power consumption, this has been verified in many reviews. 3rd party 4090s are exception, certain models use higher TDP and aggressive voltages. The ROG Strix 4090 will run at 500 watts for example(and will perform better than FE cards)

• Thermals

The 4090 Founders Edition has good enough cooling to run below 80 degrees at full load in a big case and good airflow. Without good airflow, the card will run hotter and will thermal throttle Thermal throttling for the RTX 4090 starts at 82 degrees for GPU Die and around 110 degrees for memory Keep in mind, the new cards produce a lot of heat inside the case, hence you need good airflow and big enough case. It is not recommended to use a CPU air cooler, it will perform badly with all the heat coming from the GPU backplate. On another note, 2 GPUs in a single machine is now a tougher task. Even if you find a board that could physically fit 2 cards, the cards will run hot and loud, most likely the top GPU will thermal throttle(without access to fresh air). The way around this is using riser cables in an open rack, or water-cooling. Undervolting could be helpful as well

• Memory pooling through NVlink

The RTX 4090 doesn't support NVlink, so memory pooling between multiple cards is not possible with the new generation. If NVlink is important in your workflow, please share your feedback in this thread, which we share directly with Nvidia

• Power Supply

The RTX 4090 uses a new 12 pin connector called 12VHPWR, it is able to draw up to 600 Watts. The box includes an adapter from 4x 8 pins to the new 12 pin connector. New ATX 3.0 power supplies will have native 12 pin connectors, but until this is released people will be using the conversion adapter included in the box. There is controversy now on how safe these adapters are, some are worried that it will cause issues on the long run. We will see about that The 4090 requires 850 Watts power supply minimum and 1000 watts for a Threadripper system

• Pricing

The 4090 is out of stock in many places now similar to Ampere's launch in 2020. MSRP is 1600$ but again it doesn't exist at the moment. Some 3rd party cards are available at 2400$ and higher which is not great.

• Gaming

For 4k gaming, the 4090 is 2x faster on average and up to 3x faster in some games, native 4k rendering(DLSS off). This is a big leap for 4k gaming, I think this is the first time 4k gaming on recent titles is possible at all(a good gaming experience) FYI, the 3090 falls short of running CyperPunk 2077 in 4k Ultra setting. I get around 25 FPS (Ultra settings, DlSS off) The 4090 is able to push FPS to nearly 3x in this game, and with DLSS 3.0, +120 FPS is possible, it is short of a miracle and will increase the demand for the new GPUs I think, now that we have many 4k monitors capable of 120 hz and higher. Talking about myself, a good gaming experience starts at 120 FPS. Anything lower might be playable but the experience is a lot worse. I have a 4k 120hz monitor at the moment, In CP 2077 I turn down the settings to get high frame rate rather than running 30-40 FPS at Ultra settings.

• Multi-GPU workstations

Most people will most like have a single GPU at this point of time, on one hand it is powerful enough, and other hand it is harder than ever to build and cool 2 GPUs(or more) in one workstation, but still possible.
If you plan on using 2x 4090s in your workstation there are multiple ways around this. I will list here starting from the easiest

First solution,
-Some boards have enough spacing between PCIe slots to physically fit 2 GPUs directly on the board, like the X670 GAMING E. You will need to use the first and third PCIe slots with 5 spacing between them. You will have 1 cm of clearance between 2x 4090 Founders Edition cards
-This board has enough bandwidth for the GPUs as well, first PCIe slot will run at Gen 5 x16 and third PCIe slot will run at Gen 4 x4. It should be more than enough bandwidth for the cards(You need to specify the bandwidth for PCIE_3 in bios and you are limited to a single m.2 NVMe drive)
-Finding a suitable board is half the work, you will need a big case with good airflow. Most cases will have the power supply cover or the power supply itself block the second card, be careful with that. one good case is the ROG Strix Helios, which will house 2x 4090s without issues
-The Helios case is equipped with 3x 140mm fans at the front, great airflow for the GPUs
-Airflow is very important here, there will be so much hot air inside the case. You shouldn't use an Aircooler in this case, it will perform badly with all the heat coming from the GPU backplate.

Second solution,
-Using a mining rack and shielded riser cables, this way you can use 2x 4090s or more in one machine up to 8 cards. I talk about this in details here

Third solution,
-Water-cooling, you will remove the massive cooler shroud for the 4090 and use a water block. The card will be single-slot in this case, you will be able to fit it directly on your board. There are no blocks available so far for the 4090s, once they are available feel free to DM me for details about this workflow

Best,
Muhammed

[spencerrayfitch]

Great article! This really makes me contemplate getting the 4090 how do you have to see about selling my dual 3090s. Decisions decisions.

[Muhammed_Hamed]

Dual 3090s are still great! They support NVlink and memory pooling
If there is a chance you can move to a second machine for rendering, it is the best case scenario I think
For me personally, I bought 4x 3090s at +3000 Euros last year. I will not be selling these even if I wanted to

Best,
Muhammed

[filip]

Good summary, thanks Muhammed!