Is it worth upgrading from two 3080ti to one 4090?

k886860

I currently have 2 copies of the msi supreme 3080ti.

A second 3080ti only for iray rendering is a bit unsatisfying.
Of course, rendering using iray with two 3080ti shows fast rendering. For that reason, after disposing of one 3080ti in the past, I was disappointed with the rendering speed and bought it again.
I did a search, but there was only information that the rendering speed of the 4090 was fast, but I didn't know exactly how fast it was.
The 4090 in one piece can use twice as much memory as the 3080ti, and of course the rendering speed is expected to be faster, but I wonder how fast it is compared to the 3080ti in two pieces.
Currently, the used market price of the 3080ti in my country is about $ 650. Disposing of 2 will get you around $1300, but you'll have to shell out around $2000 for a plain 4090 model. Will there be enough merit to buy a 4090 by disposing of two 3080ti and paying an additional $700 there?

Gordig

Yes.

crosswind

The 'rendering speed' mostly relies on the total quantity of CUDA cores. Two 3080ti have 20480 CUDA cores, one 4090 has 16384, the gap is 4000+. So the rendering speed with two 3080ti is definitely faster than a single 4090 for a certain same scene.
You may refer to the comparison done by a group of Daz users in here: https://docs.google.com/spreadsheets/d/1NlxDj5-bpwy_WXK_9FrZ42UPZH1SmYZkfycoCNUln_U/edit#gid=0. may check line 5, 6 and 9, etc. which is similar to your conditions. The scene duf file for test is on the top of the sheet... I have similar total CUDAs around 20000 and have tested with this scene. The result also proved to be faster than a single 4090 in comparison with the test results in the above sheet and with a couple of my friends who have 4090 as well ~

So in your case, I don't think there'll be enough merit to replace your cards with one 4090 in terms of rendering in DAZ at least...

Richard Haseltine

crosswind said:

The 'rendering speed' mostly relies on the total quantity of CUDA cores. Two 3080ti have 20480 CUDA cores, one 4090 has 16384, the gap is 4000+. So the rendering speed with two 3080ti is definitely faster than a single 4090 for a certain same scene.

Not necessarily, cores get faster (uually) between generations - though it isn't clear that the current versions of Iray are fully optimised for the 40x0 cards.

You may refer to the comparison done by a group of Daz users in here: https://docs.google.com/spreadsheets/d/1NlxDj5-bpwy_WXK_9FrZ42UPZH1SmYZkfycoCNUln_U/edit#gid=0. may check line 5, 6 and 9, etc. which is similar to your conditions. The scene duf file for test is on the top of the sheet... I have similar total CUDAs around 20000 and have tested with this scene. The result also proved to be faster than a single 4090 in comparison with the test results in the above sheet and with a couple of my friend who have 4090 as well ~

So in your case, I don't think there'll be enough merit to replace your cards with one 4090 in terms of rendering in DAZ at least...

TheMysteryIsThePoint

The 4090 has 24 gigs of VRAM, and you might want to figure in electricity costs over time; the 4090 is probably more efficient.

Pickle Renderer

TheMysteryIsThePoint said:

The 4090 has 24 gigs of VRAM, and you might want to figure in electricity costs over time; the 4090 is probably more efficient.

I recently bought a 4080 16GB and am using Afterburner to run it at 80%.   I honestly can't tell the difference in performance.  I imagine the same is true of the 4090.  If you don't need to absolutely squeeze every last cycle out of it, you can get away with lower power.

alan bard newcomer

upgrade one of the 3080s... even if you go past the vram on the smaller card ... based on watching my system when I ran a 980ti 6G with my 12G titan x and the x was at 10 or 11 g ... the 980 was still being used at it's capacity. 
Might not have had the entire scene in it's ram but it was definitely running along with the big card.