How much does Double Precision performance matter?

Snader

I've been looking at getting a new GPU; My Radeon 4770 is getting really long in the teeth. The GTX 750 caught my eye because it can trade blows with the R7 260x despite having a TDP of just 60 watts. I want to re-use this PC in the future as an HTPC so low power draw is definitely a big draw for me.

But. But. I found out that the double-precision of the card are... underwhelming, to put it lightly. Even being outperformed by the supercheap R7 240. Now I know that double precision is a workstation thing so I'm not worried about gaming performance. But to what degree would it impact my work on 3d modeling? Is DP used for viewport rendering, or just for texture bakes, or do Blender/Max not even use it at all?

I did a quick google and basically all I can find is the definition of it, which I already know. What I'd like to know is what software packages use it, and for which parts of their toolset. Anyone know stuff about this?

ZacD

I haven't seen any benchmarks that really show that your experience in Max or Maya is going to be significantly better with DP or workstation cards, except for some very specific use case scenarios. But I haven't used one myself.

JedTheKrampus

I took a look at a few of the Blender shaders and didn't see any double-precision variables declared. Cycles doesn't make use of double precision either afaik, although it does need CUDA if you want to have stable on-GPU pathtracing.

If you do decide to go Nvidia, I would make sure to get GTX 750 Ti instead of GTX 750, as they're quite different cards.

Snader

Different in what sense? AFAIK it's just more horsepower/cores but the same architecture? I know the 750 Ti is significantly more powerful but I've not decided whether the 13% performance increase (according to passmark) is worth the 25% price increase for me. Then again looking at just the cuda cores, that is a 25% increase.

Anyway yeah I'm contemplating the 750 Ti as well. I'm also kind of giddy to see if the new 900 series brings anything in my sights like a 950 or 960, btw. But I figured I'd ask about DP ahead of time just to be informed.

ZacD

The 750 ti has more vram and a much higher texture rate, and it ends up being closer to 20% faster in most games in the benchmarks I've looked at. Vram is very important in some 3d apps like Xnormal for GPU baking, and in Knald Vram effects max texture sizes.

.Wiki

Snader wrote: »

Anyway yeah I'm contemplating the 750 Ti as well. I'm also kind of giddy to see if the new 900 series brings anything in my sights like a 950 or 960, btw.

The 750 and 750ti are already powered by the maxwell gpu. The 900series currently is only the high end maxwell series. Maybe nvidia does the same again and the 950 and 950ti will make use of a new architecture which will be present in the next high end series.

Snader

Goddamnit why do these companies always make such a mess of their enumeration? I completely forgot to check the architectures of the 780... I'd assumed that the entire 700 series was the same architecture, and that the 900 series was just something like more clocks, more memory and a smaller production scale, along the lines of intel tick/tock.

I'm a bit tired and will dig deeper when my brain isn't as fucky, but looks like it'll be the 750 Ti in the end.

.Wiki

Snader wrote: »

I'm a bit tired and will dig deeper when my brain isn't as fucky, but looks like it'll be the 750 Ti in the end.

I got a 650ti in my home computer. Performance wise it´s the same card. But the 750 series has nearly half the power consumption and so there are cards with passive cooling.
The gaming performance is good. I can play my actual games (battlefield 3, x-rebirth, hitman absolution) on high settings in native resolution. Only in battlefield i had to turn off the anti aliasing. But i only got a core i3 so the computer is not that powerful.

Snader

So I just ordered the EVGA 750 Ti SuperClocked for €139.99.



Went for the Ti because more cores and double the memory.
Went for EVGA because displayport and a very short card; a lot of versions are dual fans. Also a teensy bit because of aesthetics =P.
Went for the SuperClocked version because for me the price difference would be €5, and the performance difference is around 15%, with negligible heat and electricity differences.

In the end, this is pretty much the most powerful card in such a small package, without having to fiddle with overclocking myself (there's still room though...) or resorting to an unknown brand.

Thanks for the feedback guys.


edit: looks like I get a copy of rise of the triad as well. bonus!