How much sys ram to feed a 3090?
oddbob
Posts: 396
Hi,
Long time no post. Just came back to Studio after a long time with Poser & v4/m4. Bought some Genesis stuff in the sale and I'm impressed so far but I've not tried anything taxing yet. If I'm rendering and doing simulations on the GPU how much system ram do I need to stop it falling over before I get to rendering? Currently have 32 gb. Thanks.
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The rought rule-oof-thumb is at least twice as much system memory as GPU memory (because Daz Studio needs to create an in-memory version of the data for sending to Iray, plus its own working memory - not that there is an exact match, but they tend to be comparable).
The short answer is 2 to 3 times VRAM, depending on who you ask. So a 24 GB VRAM card would require a minimum of 48GB system RAM to get best results, possibly as much as 72GB -- again, opinions vary.
Here's another discussion touching on this very subject from a few weeks back.
https://www.daz3d.com/forums/discussion/538901/the-8-16-32-64-gb-ram-argument/p1
My set up rig has 32 gig of Ram and a 3090. Works just fine.
How much of the card's memory do you use? If your scenes are not pushing the card's limits they won't need as much system memory for preparation.
I'm usually using about 17 gig of it on my latest project.
Which means you are about on the two-times line in effect.
Close to it. I don't typically use that rig for rendering. However, over the summer the motherboard AND CPU in my TR failed, and I had to replace both. While I was waiting for that to happen, I moved my GPU enclose to my set up rig, so I was running 3090X3 out of it, and it only has 32 gig of ram. The main difference in the rendering speeds of the TR running 3 3090's and the 4790 were the load times at the beginning of the render. The TR would start the render after about a minute, the 4790 started after about 2 1/2 min. Once it all started rendering, that part was the same in both rigs. So the upshot is that all of that power in ther TR amounts to remdering a scene maybe 3 or so minutes faster using the same GPUs, but in batch rendering the times really get faster as the scenes can delete and load faster.
Thanks everyone. I'll keep an eye on my ram usage and budget for an upgrade when I start to do more involved renders.
It would be nice if daz studio could use a dedicated high speed ssd for a scratch disk like abobe software. This might speed things up. Just an Idea for next version of Daz Studio.
There are a couple of locations you should change in preferences:
Caution if you have any edition of Head Shop, no. The Daz Studio temp folder 'must be' the default location.
I have found there is no need to go above 2:1 ratio so a standard 64GB configuration is fine. To max out 3090 chances are your memory usage will have a heavier leaning for geometry. Texture decompressions need more DRAM but not geometry. For example, using more HD characters without normal maps will lower the DRAM/VRAM ratio.
...a good part depends on the texture sizes used If you have a lot of 4K textures it will use a lot of system memory. Iray compresses textures when rendering to keep a scene manageable in VRAM but that does not affect system memory.
Also if you tend to have other software open like a 2 D programme a Brower etc, that also consumes system memory as does the OS and system functions.
If you create a lot of what some refer to as "epic" scenes (such as I do), better to have the overhead and not need it. I generally use the 3x - 4x rule so for a 3060 that means 64 GB because of how memory is configured in systems today.
Depends on how one uses DS, I have an 8GB RTX 2070 Super and often had scenes using more than 32GB's of RAM while rendering with the GPU (with DS being the only program running).
Thanks for the added info everyone. I've hit 24gb sys and 9.5gb vram today just playing. I'm thinking 2 x 32 ram and leave space for more in the future.