Win7 32bit, Virtual Address Space, LAA Flag and U!

[ECH]

Hello,

I'm wanted to get some additional information regarding virtual address space of Win7 32bit. So that games and programs that are large address aware can benefit from it from the increase. So far I understand that this isn't for everyone. However, if you are able to increase the virtual address space from it's current limit of 2GB to a figure of:
bcdedit /set increaseuserva 2240
(or there about) is preferred as you don't want to switch too much from the kernal. If for any reason it doesn't work you can use:
bcdedit /deletevalue increaseuserva
to remove the instruction from the bootloader.

I've read that those that have tried this have played some games a lot more smoother. Others believe that the frame rates improved. For me, I've seen stutter removed in a few games that I thought was CPU limited. However, from what I've gathered you will need Win7 or Vista 32bit as XP 32bit doesn't allow the increase of the user virtual address space in increments of 16 (or is it 64?). You are left with /3GB option which is too much.

I've tried this with a few games and Vantage with positive results. For example:

Before the large address tweak on Win7

After the large address tweak on Win7.

After the large address tweak on Win7. And, /LargeAdresssAware flag added to 3DMarkVantage.exe. Although the total score for the 2 results are exactly the same. Scores for the CPU show the most improvement when enabling LAA for both Win7 32-bit and 3Dmarkvantage.exe.



So far the results are more seen then just looking at numbers. Games like Empire: Total Ware are stutter free now and frame rates don't seem to dip as low as it use to. In particular raining during a battle is stutter free. Road to Independence videos do not stutter, etc. If others are getting positive results from this, why isn't this more discussed with the public at large? Why isn't there more information about this? So far, I have no need for a 64bit OS at this point.

Thoughts?

 

[ECH]

Does anyone have any insight on this?

 

[H2SO4]

Does anyone have any insight on this?

There's more to being LAA than just having that flag set in the image header. An application has to be designed to deal with a larger (>2GB) address space. Otherwise, if you edit the binary to have it claim LAA capabilities the results will be unpredictable. Sometimes it'll be OK, for a while, and sometimes it won't. It's a horrible idea for a business system but it doesn't really matter for a game.

Also, increasing the user-mode address range can only help processes which are bumping into their (default) 2GB limit. Otherwise, if the committed size of a given process is say 1GB, jacking up userVA achieves nothing but (unwanted) kernel compression.

Great questions. Have rep

 

[ECH]

Thanks for the reply. So far I know of 2 games that are large address aware:
BF2
Empire Total War

Which was why I decided to look into it more. From what I've seen Empire Total War just plays better for me doing this. As for BF2 I have had no problems. And, no problems in general so far.

 

[H2SO4]

Thanks for the reply. So far I know of 2 games that are large address aware:
BF2
Empire Total War

Which was why I decided to look into it more. From what I've seen Empire Total War just plays better for me doing this. As for BF2 I have had no problems. And, no problems in general so far.

Perhaps I misunderstood parts of your post.

If an executable is designed to be LAA, then by all means it's a good idea to bump up the userVA. The process presumably has large memory needs, so the additional up-to-1GB of space will benefit performance. Incidentally, a LAA process can allocate up to 4GB when running under x64.

Otherwise, if the LAA flag is "artificially" set on an executable which wasn't designed to deal with more than 2GB, results will vary from nothing at all to mysterious crashes.

 

[ECH]

No problem thanks for the insight. It was my understanding that some developers may use a large address flag (32-bit games) to prevent the game from running out of address space. Thus improving stability (more or less).

I understand that just adding the flag for games that don't use the larger address space may cause problems. So that would be "at your own risk". In which the worst case scenario would be to remove the flag.

 

[stormy13]

Does anyone have any insight on this?

26 points in 3DMark, that can happen from one run to the other. That is the kind of thing you used to see from some when a new video driver came out, they would claim how it was the best driver ever because their 3dMark score went up a few points (or the inverse and claim the driver was garbage because it went down a couple). Basically what I'm trying to say is that the difference between the two doesn't mean a thing.

P.S. Filling in your system specs would help.

 

[ECH]

Does anyone have any insight on this?

26 points in 3DMark, that can happen from one run to the other. That is the kind of thing you used to see from some when a new video driver came out, they would claim how it was the best driver ever because their 3dMark score went up a few points (or the inverse and claim the driver was garbage because it went down a couple). Basically what I'm trying to say is that the difference between the two doesn't mean a thing.

P.S. Filling in your system specs would help.

Perhaps for you that is a normal fluctuation however for me the results were the same between runs when nothing was changed. I guess it all depends on your PC.

 

[stormy13]

Run it at least three time each way and take the average. Then if there is a difference, it might be worth getting excited about.

 

[ECH]

And what makes you think I have not? Besides, averages don't show the actual results so there no need to use averages.

 

[H2SO4]

No problem thanks for the insight. It was my understanding that some developers may use a large address flag (32-bit games) to prevent the game from running out of address space. Thus improving stability (more or less).

A game is like any other process in this instance. If the memory needs are so large that the standard 2GB barrier becomes limiting, then at development time they may throw in extra logic for what to do when running on machines with an increased userVA.

Hence, it's more about increasing performance than stability. Even a non-LAA process is not meant to handle running into the standard 2GB limit by crashing - that's just bad design or (more likely) oversight. Instead, the process is meant to throttle itself so that it never absolutely runs out of space and dies.

I understand that just adding the flag for games that don't use the larger address space may cause problems. So that would be "at your own risk". In which the worst case scenario would be to remove the flag.

Yeah, that's analogous to giving a million bucks to a drug addict - you can't be quite sure how they'll react