OTOY Forums

Hi guys,

I've just got the opportunity to buy a couple of GTX 590 cards really cheap (around 300 euros each) here in my country, which I'm strongly considering. However I'm doubting that the 1,5 GB of RAM that there is for each GPU in the card is enough.

Before I rush out and buy 4 of these 590s, I'd like to ask those of you here who has these cards - are you having any trouble with the limited amount of RAM for everyday use (mixed scenes, interior and exterior shots?) - and how are you dealing with the limited amount of RAM in your scenes?

I will primarily be using the cards for making animations in 1080p resolution.

Really looking forward to hear your experiences and advice!

Best
Henrik

Hi Henrik - Welcome to Octane bro!

This is a tricky one, and has been the topic of many discussions (and even arguments) regarding how much VRAM is enough. If you feel very confident that you are not going to be working at higher res than 1080p most times, you will find that this res uses very little vram if you do not have tons and tons of textures (especially if you are staying away from 4k) or millions of polys. Before upgrading to these four 580 3-giggers (which cost me $700 total for used) I used two 460s. And only ran into memory fails twice in roughly a year doing commercial work. One was a really complex high-res and the other had millions of polys.

2.0 is going to have region rendering, which will presumably lower the vram requirement to just the region being rendered - allowing for split renders. And managing your textures well (efficient UV islands and avoiding higher-than-needed res) will make a world of difference too. And when Octane Cloud rendering comes along, well, that will probably help even more...

So a lot - and I mean a lot - can be done with one gig or 1.5 gig... But the bottom line is that when hit your vram limit (or texture number limit) this can bring some serious grief. And if a time comes that your back is smashed up against a wall, with a dead-serious-drop-dead-deadline and a client is breathing down your effing neck, you might find that you are the most miserable bastard around...

Textures and geometry are what fill up VRAM. It is true that the image being rendered also uses some but until renderpasses and multi layer EXR support is added the render image (film back if you like) will only ever use up as much VRAM as it would take to hold a single texture of the same resolution and colour depth. It is really your scene complexity that dictates the amount of VRAM needed and I doubt that will change with region render as the whole scene will still need to be transferred to the card before the render begins.

T.

You can never have enough VRAM. Get as much VRAM on the card as you can afford.

Untrue. Do your homework and make an informed decision based on your own personal and unique needs. I have no doubt that folks have run out and bought turds like GTX 640 4GB, based on statements like that. Not everyone does ridiculously complex archviz scenes with dozens of different vegetation in their landscaping... I said it before, I'll say it again - If money were an issue and I had to make a choice between the two, I would take raw rendering horsepower over vram any effing day of the week. I personally need 3GB to be on the safe side, because my stuff can get pretty complex and deadlines are often critical. For many, this is not the case.

Here's the interesting thing about that particular turd, Frank:

If the network rendering thing is true you could pretty cheaply end up with a whole bunch of GTX640s as render nodes each with 4GB of ram. Doing the math myself, I'd need a much beefier desktop to handle the power needs of say a single 700 class 4GB card than a couple of cheap-ass commodity used desktops to which I could plug in 640s.

But I'd love to hear your argument against it...

For my own, I build mainly large outdoor scenes (landscapes or city view with many detailed buildings and vehicles) and I never have enough VRAM. I have currently two GTX 580 3GB (around 2.880 GB actually available), and most of my scenes require that I cheat with prerendered backgrounds or other tricks. Having a lot of memory offers more possibilities than speed.

My point of view is that you can render at night if you have few computing power, but you can't render anything if your whole scene doesn't fit in memory.

Personally i bought one GTX 590 a couple of years ago... when i saw the specs i didn't realise that the 3gb of memory is shared by the two GPU´s, meaning that you would have just 1,5gb to work with... sincerely i was really pissed off when i tried to use it for the first time... for architecture viz 1,5gb isnt enough for almost nothing (if you want to use real grass and such)... in my oppinion go for the biggest memory you can find... its never too much... i am dreaming abou some Tegra GPU´s with 12gb of VRAM for some time now... Titan Z was a huge deception for me...

What percent of Octane users are setting up their own render farms? 10%?... 20%?... My guess is that the majority want to be and will be working on a single workstation. And with cloud coming in near future, I would never set up a farm right now. My 580s are perfect. Exactly what I need. I made an informed decision and there has been no buyers remorse whatsoever.

A 580 3GB will absolutely destroy a 640 4GB and make it crawl away in shame. I got two of mine for $200 each and the others for $150 each... If someone were to build a cute little farm of 640 4GBs (in flimsy PCs made of tin and plastic with noisy case fans) to match the power of these four 580s, my math tells me that I would not be sitting in a room full of cheap-ass noisy PCs. Yes, they could be in another room.. but still... I'd rather not be my own personal network admin.

But please folks, don't think that I am against massive amounts of vram. For many, they need every stinking GB they can get their paws on. For others, they will never even come close to 3 or 4 gigs. All I try to do is educate people that they can get quite a lot of rendering for cheap on eBay and Craigslist etc. If you know your scenes are going to be lower polys and smaller/fewer textures than us power users, go cheap and powerful and you will be thrilled. You will not be making a life-long commitment and can upgrade later as needed.

Hey, good luck with your farm, pard! Be sure to post specs and M/s etc!

I do think this is a bad time to want to set up a farm. If/when the cloud comes out, it might be much better for cost/efficiency than making your own farm. You also have to deal with electricity and maintenance.

For me, I'll use both because we have 3 computers here at work that use Octane. So when one of us arnt rendering, the other person can tap into those GPUs for added speed. Then we can use the cloud for longer scenes/things that need to be done quick.


For GPUs, 1.5 VRAM is more than enough for us, so it really matters what you are using it for.

I was looking on amazon because we might want to get a couple of more cards. A 780 3GB superclocked by EVGA (single GPU, so its actually 3 GB) is $520. A 640 4 GB is $120.

A 780 has 2,304 CUDA cores, a 640 has 384... Now, there's more than just cores when speed is concerned, but using that as a base, the 780 should be something like 6x as fast. The 780 is 4.3x as much, so you are getting more bang for your buck. If you take that low end desktop and only put in 1 780 instead of 4 640s, you will have more speed with a small upcharge. But you will have more space in that desktop to place another 780. For the 640 route, you would then need to get another barebones system.
you get 1 GB less VRAM, so that does need to be taken into account too though.

Unless that 1 GB of VRAM is important to you, I would definitely go with the 780.