VRAM - Limit? No Limit? Proof?

[Maverick827]

I'm finalizing a new high-end build. I've read over a hundred threads across dozens of forums and I have yet to find definitive proof that Skyrim has a vram limit, nor have I found proof that it doesn't.

 

A poster on Tomshardware will say that they're seeing 5GB of vram used, whereas a thread on Overclockers will state that there is a 4GB limit. A poster here will claim a 3.X GB limit due to Skyrim being a 32 bit application, and someone will follow up and say that limit only applies to system RAM and not vram.

 

I've read someone say that their 3GB GPU is fine on a 5760 x 1080 display, fully modded, and immediately after that I'd read about how someone's conservatively modded 2560 x 1440 setup is pushing their 4GB card. There's world maps from the 14th Century that have more reliable information that vram usage in Skyrim.

 

Does anyone somehow have any proof to either? I'm not sure what would even suffice at this point. A GPU chip architect chiming in, maybe? If you believe that Skyrim is vram capped, how do you explain those who are seeing higher usage numbers? If you don't believe it is, are you only going by a monitoring program, or have you actually had a 4GB card work where a 2GB card crashed?

[welsher]

I don't think there is a limit - haven't got any proof of that but still. I have a GTX 460 with 750mb of RAM, over 115 mods installed (many of them graphical - lots of high quality graphics replacers, official HD texture packs, an ENB etc) and my game runs stable at 40 fps outdoors and 60 indoors (I have an unresolved crashing issue that only appeared yesterday - not sure what's causing that - could be VRAM but regardless it proves that 4 GB of Vram is more than enough). I can't see this game eating 5 GB of VRAM unless you go absolutely nuts with the graphical mods. I was looking around on Tom's Hardware forums about this and found a quote that sums it up pretty will;

 

'Skyrim doesn't need more than about 2-3 GB of vram, regardless of how much it will fill.'

Edited June 13, 2013 by welsher

[Maverick827]

What resolution are you running at?

[welsher]

1280 x 960, considering dropping to 1152 x 864 or something though - I have to make some sacrifices to make sure my gpu doesn't explode with all the mods I was using. How do you intend to run the game? As in what resolution etc?

 

 

Have a look around Youtube, there are 1440p clips of people running around in Skyrim with what looks like some pretty hefty mods (this guy's game looks ridiculous but that's beside the point :P).

 

 

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

Edited June 13, 2013 by welsher

[Maverick827]

I intend to run it at 2560 x 1440. I don't think that video is indicative of what most people consider to be a "maxed" Skyrim. The description says he has a lot of features turned off, and I didn't see any DDoF indicating any sort of high-end ENB. There's no mention of what textures he's using, and it's difficult to tell through a YouTube video as well as with whatever art style he has. Edited June 13, 2013 by Maverick827

[welsher]

He's using texture packs including WATER as well as an overhaul of Whiterun called Beautiful Whiterun (IIRC, it's got ugly blue roofs but it replaces most vanilla textures in Whiterun with HD ones). He's also using an older version of Superb ENB RL which is the top rated ENB on the nexus; from personal experience it gives me more of a performance hit than ENB's that have SSAO and Bokeh DOF enabled. Granted he does have some features turned off, but he is recording with Fraps after all.

 

I also found this quick video of the memory usage of a 3GB 7970 running Skyrim at 2560 x 1440 on the Ultra preset;

 

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

 

 

I'd like to see more info on this topic though as I can't find anything definitive either.

Edited June 13, 2013 by welsher

[Maverick827]

The video unfortunately cuts out right before he would have reached his vram limit. ;D

[Bloodinfested]

For the ppl saying that there is a 4g limit on 32 bit application / exe they are referring to the onboard ram not video ram. Far as Vram goes I got 2.5G I have caped it before and it will ctd. I imagine if you really wanted to you could consume more then 4g of vram you start messing with ini ugridstoload combo with other distance ini then mods like warzones that add a bunch of npcs plus using HD textures. More you push out your view distance or more cells to load the more your card is rendering as a result your consuming more vram. I use to have my ugridstoload 7 but I didnt like the fps hit and more important I notice is was kind of unstable. Off hand Im not aware of an cap on your vram itself.

[Georgiegril]

How graphics cards and other devices affect memory limits

Devices have to map their memory below 4 GB for compatibility with non-PAE-aware Windows releases. Therefore, if the system has 4GB of RAM, some of it is either disabled or is remapped above 4GB by the BIOS. If the memory is remapped, X64 Windows can use this memory. X86 client versions of Windows don’t support physical memory above the 4GB mark, so they can’t access these remapped regions. Any X64 Windows or X86 Server release can.

X86 client versions with PAE enabled do have a usable 37-bit (128 GB) physical address space. The limit that these versions impose is the highest permitted physical RAM address, not the size of the IO space. That means PAE-aware drivers can actually use physical space above 4 GB if they want. For example, drivers could map the "lost" memory regions located above 4 GB and expose this memory as a RAM disk.

 

This is from the Windows page that discusses memory limits on various systems.

[prod80]

A good engine will always fill up your VRAM until it's max with anything that it thinks it MIGHT need.

This is the most effective way of designing your engine.

 

So, if done right, it will always fill your vid card right up till it's max or very close to it. That's why reports are always off - they would need to test the engine, what it does, not monitor the VRAM on a card.

 

Having not enough VRAM and too high textures means you get stuttering (not micro, reall badass stutters) and FPS drops while your system is trying to keep up swapping in and out textures.