viking

Sorry Nshell, that isn't how it works. There are system functions (called "system calls") that the program (skyrim) calls which expect a 32-bit integer for a 32-bit program, irrespective of whether the OS is 32 or 64 bit. It isn't a matter of being fast or slow, it simply wouldn't work. If you had multiple lists of pointers each with 2^32 entries, each list would point to the same memory locations. This limitation of 32-bit is a large driving factor behind the adoption of 64-bit applications. aleksanderdev, I am surprised you are able to get up to 5.2GB of VRAM, mind sharing your setup, modlist, and location where you reached that?

Because Bethesda. And consoles. And because it was written as a 32-bit program. Bethesda could theoretically rewrite Skyrim as 64-bit, but the only people it would help would be PC modders, so they have little incentive to invest in it. "Requesting multiple address spaces" is not really possible. All of the variables are 32 bit and memory access functions take a single 32 bit integer, so even if you requested "multiple address spaces" you wouldn't be able to tell the OS that you wanted to get to them. EDIT: I should be clear: The maximum size of a variable is 32 bits; an integer (which is used as a memory pointer) is 32 bits, but other types are of different sizes <= 32bits in a 32-bit program.

I'm not entirely sure what you are getting at, Nshell. Yes, device drivers need to do some form of 64-bit arithmetic, but this is because they are in kernel space, not user space. Even if you ran Skyrim as administrator, this would not run in kernel space (thus not do 64-bit arithmetic). Also, you are correct about the registry value that sets how much memory you can use in 32-bit versions of windows vista and windows 7, but again, I'm not sure how it is relelvant. Skyrim is limited to 4GB of memory (with the LAA switch enabled) because it is a 32-bit program. C++ based 32-bit programs, which Skyrim is, uses 32-bit integers to address the memory addresses in their virtual memory tables. This is a limitation of both how the program was written, and the specific compiler used to compile the program (thus you cannot typically just re-compile it).

Just as an FYI, this is not solved in the 1.9 beta.

JudgementJay, could you post your mod list? I have been playing around with this for a good part of the day, and I'm just amazed that you can get ~1.8GB of Ram with TPC at twice my resolution. Just jumping to riverwood with a new character puts me at more than 2.1GB. The worst locations for me are in cities, particularly Windhelm, which jumping there puts me at about 2.6GB...and entering Candlehearth Hall then adds another 500MB and CTD. These numbers are with SRO and Skyrim HD disabled (which seemed to add the most based on my testing).

Your point about large sound files being an issue is interesting. I do have two mods with 500mb+ (on disk) of sound files. I'll try to see how that affects memory when I get a chance. As for how enb AA affects memory usage. 119 was the last version of enb to support hardware AA, which would have been outside of the memory space of skyrim. Newer versions, however, are software based. The dll version of enb, I believe, is loaded by skyrim into skyrim's addressable memory (can someone confirm this?). Enb does not use a large amount of ram in my experience, but does affect it some. It is unfortunate that the cheese wedge idea didn't work for our purposes. I am also curious what attk does to allow more wedges if more wedges don't affect memory usage.

Z, I am really glad you have been posting here, and your benchmark is excellent and informative. Unfortunately I can't seem to get a couple of your graphs on your benchmark to enlarge...not sure if that is just my issue or not, but even still, the chart gives a pretty good idea of what you mean. I do think you have enough vram to experience what we are talking about, just not in the normal play of the game. If you are interested, you could try the "cheese wedge effect" discussed earlier in the thread and see if you get a ctd at 3.1GB. I am pretty sure you are right about Process Explorer listing dynamic and static vram usage, but I'll have to look closer when I'm at a windows computer. I have tried running it without Attk. It does lower the ram usage slightly, but not significantly. I will have to try the full version and see if it makes a difference. I'll have to be honest, I haven't read the description of Attk, so I don't know exactly what it does (besides help manage memory somehow).Â

If anyone comes up with an easy/quick way to test this, please post it here. I'll second torminater, at least for 2.2.0 with all the max options I didn't have this issue.

techangel85: Thanks for the clarification. I'll probably just let a mod change the title from now on. I agree with your testing idea. We need a couple of people, besides Neo and myself, that have 6GB+ RAM, to help test the limit. The cheese wedge idea is interesting, but I'm not sure how to implement that. If we would rather go the mod way, we need to determine several Ram heavy/Vram light mods, such as Interesting NPCs, that we can use. Any other recommendations on how we can run this?

Sorry, I had changed the thread to solved...because at one point it seemed like we weren't going to get any further. This has obviously changed so thanks to whomever changed it back.

I'm going to try to get the thread back on track: Besidilo, I'm not sure who got your name wrong. If it was me, sorry about that. I know very little about VRAM. A link with more info would be more helpful. The more we understand about the behavior of VRAM the more likely we are to understand this issue. I read in some forum somewhere (highly reliable...) that Skyrim was partially directx10. Don't trust me on that. It makes far more sense for it to be directx9, especially since xbox is limited to that. Salvador, I agree that the references is Besidilo's links were excellent. I just had a hard time following the first one. I didn't notice anything incorrect in the links, there were just a few times when things like the maximum ram in a system was taken to be a constant across all systems. Again, the information was correct, just difficult to follow and left some key pieces of information out IMO. z recommended several test we can run to test the memory/vram correlation, and I will run them this weekend. Are there any other ideas on how we can get to the root of this issue?Â

I think that this is a very important point. Assuming memory is the issue (which can't do with complete certainty), the issue very easily could be a limitation of the CreationKit engine (is that what it's called?).

I shouldn't have used the term "pre-cached" since caching memory already implies a certain buffer. My point was to not get confused by the extra memory that would be cached in any case, any application may appear to use more memory than it actually needs, up until the point it runs out completely. You can't measure VRAM usage accurately, and that has been addressed a lot of times already. You're probably thinking about the extra textures that has been buffered to the video RAM, but aren't actually used by the engine. With regards to the memory limitation, Dx9 mirrors VRAM onto the system memory, in turn reducing your actual system RAM limit by the amount of VRAM in use for any process. Microsoft got rid of this limitation in DirectX 10. x86 processes with Large Address Aware patch can use up to 4GB total system memory. In other words, it's complicated. But it can be assumed that a crash would occur when Skyrim with LAA suddenly requires more than 4GB of RAM+VRAM. How to measure that point accurately is another matter. At least that's how I understand it. It is a shame that we keep posting at the same time. I assume that your second paragraph means that virtual memory is different than physical memory, and in that we are in agreement. I'm not sure why you think that you can't measure VRAM usage accurately. I agree it is difficult to pin VRAM usage to a particular application, but you can get pretty good idea. I addressed your other points in my previous post.

Alright. I finally had a chance to read through both of these. Up front, the gamasutra article is quite misleading and I wouldn't recommend it. The links it references are all high quality and the author did know what he was talking about (for the most part), but leaves out some essential bits if you aren't familiar with the area. The second link is accurate, but somewhat dated. I don't really feel like going into more detail here, but can if someone is interested. In response to your comment, we still are not sure exactly how Skyrim manages its vram. A link earlier in this thread (and actually in your first link) discusses the windows patch that helps manage vram outside of the address space of the program. In versions of directx earlier than 10, the vram is mirrored in the application address space, but I haven't seen any clear indications of skyrim being strictly directx 10 or strictly directx 9 (please link if you can), and so, in my opinion, we are unable to answer with any certainty if all vram is always mirrored in application ram for skyrim. Note that this is a different issue than if vram on the graphics card is in the same address space as the application. Based on my experience, this is not the case. My skyrim ram + skyrim vram often exceed 4gb. As for if you should get a 4GB graphics card, I often go above 2GB of VRAM, but have yet to hit 3GB vram. I think you will still find an advantage of having a 3GB+ graphics card.

Besidilo: I have not yet read the articles that you linked to, but they look very interesting. I also am not sure what you mean by "pre-cached" memory, but would be interested if you could explain more. Your comment that LAA applications are limited to 4GB for System Ram + VRam, however, doesn't line up with what I have seen. I often see my VRAM at about 2.7 GB and my Ram at about 3.1 GB...which is obviously more than 4GB. The only way I can reconcile your comment with my experience is if the VRAM that is mirrored in RAM is not counted twice. That is certainly a possibility. I apologize if this is addressed in your articles, and feel free to respond to that effect if that is the case. I would like to point out for Salvador's sake, and for everyone else reading this thread, that we have done only very limited tests about the mirroring of VRAM and RAM. It is not outside the realm of possibility that the VRAM is temporarily loaded into memory before being forwarded to VRAM...or something to that effect. We also don't know for sure if the VRAM is considered as part of the 4GB address space. All we know for certain at this point is that texture files in skyrim DO affect VRAM usage AND Ram usage. I'll update this comment once I have a chance to read Besidilo's links, they look to have a lot of good information in them.