GTX 780 slower than GTX 590?

[regionfive]

I Just unpacked 2 EVGA GTX 780 6GB OC Edition and replaced 2 GTX 590. My excitement about the expected performance boost got washed away, when I tried to render a same exact scene.... It is slower now! A scene that rendered at around 19 MS/sec renders at 14 MS/sec now
Is this even possible? Is Kepler that inefficient?
4600 Cores (2x780) vs 2000 cores (2x590). I thought Performance scales directly with the number of shader cores?

It is the same for Octane 1.2 and Octane 1.5.

HELP please!!

[whersmy]

It`s the difference in architecture between Fermi VS Kepler. Fermi cores scale better...

Though the 590`s get hotter, use more watts and have less RAM.

[regionfive]

Yeah I´ve read that there is a little drawback with Kepler, but I wouldn´t have thought it´s that severe
That actually means I have bought less performance for 1000 €... I still can´t belive that.

[riggles]

I've read that 1 Fermi core is equivalent to between 2-3 Kepler cores. Yea, that's a bit of a bummer if you're upgrading from one to the other. However, if you need more VRAM (or need better power efficiency), you don't have that many options.

[regionfive]

Wow...this is annoying....
I need more performance, what can I do? Two Titan Blacks would double the price. Plus I have a deadline this month. I thought I´d save half of the Rendertime... Is there something licke a PCi Rigg, where i can plug 4 cards into?

FYI

This is the performance on an exact same Scene:

2x590



2x780

[kavorka]

You can buy an external thing (forget what its called right now) that can house extra cards and plugs into your computer, effectivly increasing the number of PCI slots your computer has. You could get that and plug your 590s into it, combining your speeds together.

I think they run around $1k

[kavorka]

A quick search found this:

http://www.youtube.com/watch?v=v2UWrwl0hlc

Kinda explains how they work. There are several topics in these forums that talk about them and what to get or not get.

[riggles]

Wow...this is annoying....
I need more performance, what can I do? Two Titan Blacks would double the price. Plus I have a deadline this month. I thought I´d save half of the Rendertime... Is there something licke a PCi Rigg, where i can plug 4 cards into?

The PCI rig that can hold your 4 cards is available from companies like Netstor and Cubix. The Netstor runs ~$2,500. $2,200 for the unit and ~$250 for the host card that goes in your computer. The Cubix one is like $3,000.

http://www.netstor.com.tw/_03/03_02.php?MTEx
http://www.cubixgpu.com/gpu-xpander-desktop

[glimpse]

if You need four cards only, external PCIe solution isn't the best value here.

Simple 1150/1155 mobo with PLX (capable of 4way /read: four PCIe slots/ sli), Quad CPU, compatible ram (let's say 32GB) & power supply would cost You less (Only if You need more than 4cards start looking into expanders).

Before that put four of 6gigers into a box & be happy for a while - that would probably be the best deal.

Alternatively You can get back You 780s & buy bunch of second hand cards for the same price & solution will faster..However, it's not future proof, as You'll probably need more & more of vRAM with time.


Next time, before making an upgrade do some homework. The forum exist for the reason. You'll not look stupid for asking question (in a past we had some guys who bought 690 instead of Titans for the same price..-that was a dumb deal too, but it's their own fault - noOne to blame here).

[acc24ex]

- yep I think I even raged a couple of times about nvidia's terrible performance when I checked the numbers, in 2-3 years they have only delivered lower temps and more VRAM - this performance issue was here since the 6xx series, nothing changed much

- BTW are you willing to sell your 590s ?

- another solution: pcie extenders - these here are PCIE via USB cable
http://www.ebay.com/itm/pci-express-PC ... c82ff1b7c

- this one hooks up to your tiny 1x PCIE slot, or the large 16x (but runs on 1x) - you'll get improved render speeds only loading the scene might take longer

- I am sure you at least have one more 1x PCIe slot available

- or search for regular ribbon extenders

- there's a thread here with usb PCIE extenders, the guy is pretty happy with his rig

- and sell those 590gtx babies cheaply to me