Are dual graphics cards or single units best for 3 monitors (given my needs)

[jpremodeler]

This is a work rig. I run a CAD program that historically has been CPU heavy not GPU heavy for rendering. My video cards do not meet their current recommended specs and are causing me issues.

I upgraded my CPU, Mother board and RAM not too long ago but kept my old video cards. The newest release of the program I run is relying more on GPU and recommends 4 or 8 gb cards.

I use 3 monitors for work ease only. I do not do any gaming.

Question: Am I better off with 1 card that can handle 3 monitors, or 2 cards that can handle 2? I have no intention to add a 4th Monitor. What is best performance, what is best value?

After your feedback, I will probably ask for card specific advice when I shop a bit, but any specific suggestions would help. Was hoping to spend under $400.00 in total.

Let me know if I am missing anything. Thanks as always for you help!

My set up:

MB: ASUS Rampage v
CPU: i7 5960x (liquid cooled)
RAM: 16gb ddr4
GPU1: gtx580 evga
GPU2: gtx 580 evga
MON1: Acer G235H 1920 x1080
MON2: Acer G235H 1920 x1080
MON3: Acer G245HQ 1920 x1080
PWR: 950 watt silencer

 

[Mikel_4]

The one on the 1st slot close to CPU socket is the one that send video signal to monitors, on nView menu you can configure best multi monitor setup. So basically you only use GTX 580 for its OpenGL not the CUDA engine for rendering so in theory you'll get decent view port with three 1080p monitor from single GTX 580, that is program dependent where no pro card is mandatory (Solidworks or Autodesk).

If you choose big desktop mode you can use the one that connected to mini HDMI as main viewport while the 2nd as menu and the 3rd as windows explorer, your GTX 580 is doing the display, on most cases a 1080p on DVI-I don't use more than 500MB VRAM (DVI bandwidth limit)

 

[jpremodeler]

The one on the 1st slot close to CPU socket is the one that send video signal to monitors, on nView menu you can configure best multi monitor setup. So basically you only use GTX 580 for its OpenGL not the CUDA engine for rendering so in theory you'll get decent view port with three 1080p monitor from single GTX 580, that is program dependent where no pro card is mandatory (Solidworks or Autodesk).

If you choose big desktop mode you can use the one that connected to mini HDMI as main viewport while the 2nd as menu and the 3rd as windows explorer, your GTX 580 is doing the display, on most cases a 1080p on DVI-I don't use more than 500MB VRAM (DVI bandwidth limit)

I can't use the GTX580's. I need 6-8 gb memory. In looking at new cards, it seems that most will support 3 monitors and it looks like the GTX1070 will fit in my budget. If that makes sense, I will start looking at the different ones

 

[Mikel_4]

Must be huge file size you're working, if your CAD program specify 8GB VRAM then AMD RX 480 > GTX 1070 > GTX 1080, if you working on multiple files such as Solidworks or mega construction then maybe you should contact your CAD's company and ask some additional tweak/patches/advise so your GTX 580 becoming more efficient to play with.
If you feel your GTX 580 starting to reach elderly stage then consider EVGA GTX 1070 SC2 (not SC) or FTW2, couple $ pricier than regular GTX 1070 but for business we need some sort of uptime reliability, the "2" suffix is new EVGA's cooling solution called ICX (ACX 3.0 had problem when reaching peak power usage), comes with fuse and enhanced heat dissipation (offers best TDP dissipation tech among other GPU air cooling design), so rather than spinning/stopping fan(s) like Gigabyte, ICX has separate fan cooling VRAM+VRM and cooling GPU Core, simply more efficient power usage. The fuse is useful when power surge comes from monitor, so when it happens at least the fuse is the one which will be "killed" not the entire graphic card.

Rampage V has PCIE Switch (you can turn on/off installed graphic card) I suggest instate your GTX 580 on slot_2 and slot_3 with dip switch on "off". If you use LUX Render then having CPU+GPU render.

950 watt, i7 5690X = 250 to 275 watt + EVGA SC2 = 225 watt + two GTX 580 ~ 450 watt + rest (motherboard+drives+fans+pump) = 100 watt [1000 watt at peak]. If you can afford 5960X then why not ready Titanium grade PSU such as Seasonic Prime SSR TD or EVGA T2 as 1st future buy, at peak 1000 watt a titanium PSU draws ~ 1100 watt from your home socket, ~ 1150 to 1200 platinum, ~ 1175 to 1225 gold.