Will 2nd video card help with Iray

artd3D

I have a geforce 750 TI with 2 gb running dual monitors on Windows 10 pro 64 bit with 16 gb of memory and an AMD 8120 cpu.

I am thinking of adding a Gt 420 with 2gb of memory to run my monitors. Will this speed up my render times running my monitors 

on the GT 420 and will iray be able to use the additional 2gb of memory.

I'd love to be in the 980Ti snob club, but finances won't allow it at this time.

Thanks for any advice you can give me.

JD_Mortal

Gt 420 has 48 cuda-cores...

750 Ti has 640 cuda-cores...

Your gain will be less than 10%, but a gain...

 

Iray will have to distribute the whole project into each cards memory, to use the GPU. (That is just they way they choose to operate. Lame, but it's the only thing they know how to do, at the moment.)

Thus, you WILL use the 2GB, but it will not be stacked to give you 4GB of scene-rendering ability. Each card will have its own 2GB of data to chew-up and spit-out rendering-data, that will stack into the final rendering. (Or if animation, each should be doing one frame of animation, individually. Less if you use one card to render your screen-output too, including DAZ view, while rendering...)

Yes, you will see speed-gains, unless your project is over 2GB, which will force it to fall-back to CPU rendering. (Another lame thing to do, since video-cards have a direct-bus to RAM.)

The only important thing to focus on, when purchasing a card, is the "Cuda cores". The rendering engine is not "Accelerated", like 3D games. It uses the Cuda-cores code to process individual components of the rendering. Compare "Cuda-cores vs Price" to determine Price per cuda-core for the best value. (Visit ebay for some nice deals, after visiting GPU benchmark website and reading the cuda-core stats for the cards. The game-stats are a good idea of potential, but that is for "Graphic acceleration", not cuda-core performance, which is only a small part of game-rendering. Usually Physics related or post-rendering, which is not used a lot in games, but is used a lot in standard renderings.

 

Best deal...

GTX 480 (1.5GB) has 480 cores... about $70 (6.85 cores per dollar) Limited scene rendering sizes... Not what I reccomend, just listing it as a better deal than the GT-420

Good deal...

GTX 970 (4GB) has 1664 cores... about $312 (5.27 cores per dollar)

Okay deal...

GTX 980 (4GB) has 2048 cores... about $474 (4.32 cores per dollar)

Ideal...

Titan Z (12GB) has 5760 cores... about $1200 (4.80 cores per dollar) But waaaay less watts than multiple other cards. Plus it's 12GB of scenery detail you can process.

You would need 12 GTX-480's to equal ONE Titan-Z... That's a lot of power and RAM and CPU's... just to get fast 1.5GB scenes rendered, and no ability to render scenes higher than 2GB.

 

Note, "GT" = cheap internals... "GTX" = better internals, no "subsitute parts". (GT is the economy line cards. Sympathy game-rendering ability.)

mjc1016

No, Iray will not use the 2 GB on the 420 as 'additional' memory.  In GPU rendering memory does not 'stack'.  What you have on the card is all you have.  But what it will do is allow you to use ALL of the memory on the 750.  So marginal renders that get dumped to CPU rendering because Windows is eating up just enough memory to prevent them from fitting on the card will run on the card.

What I would do is look for a cheap 4 GB card...

artd3D

Thanks for all of the intelligent info, this tells me which way I want to go based

on how much I want to spend. Thanks for all of the helpfull advice, I will probably go with the the 

gtx 480.

 

Tobor

Thge 740 is not bad, but has only about 380 cores. Better than nothing. It is available in 2GB and 4GB versions, new for about $100, depending on source. Be sure to get the 4GB card, and ideally with the DDR5 memory (it actual does help a little because of the increase in memory controller speed). EBay deals also for a lot less. It's a card many gamers had, and are upgrading. By the metric above, it's only about $3.90. so way cheaper than the other cards per-CUDA.

Your power supply will need one 6-pin PCIe plug, with 20amps on the 12V rail. The 740 and 420 take the same driver (on Win7 at least), making installation pretty easy.

digitalus49

Two NVIDIA cards of the same make are highly recommended OR one very big card. The Titan Z is a complete waste of money. You are far better off getting 2 in tandom - Titan X cards. DO not use the SLI link on them. This works running Windows and MacOS (hack systems).