A Messy Transition: Practical Problems With 32bit Addressing In Windows
by Ryan Smith on July 12, 2007 12:00 PM EST- Posted in
- Software
Except in a few cases where 64-bit code is clearly faster, the primary purpose for Vista x64's existence is to resolve the problems of 32-bit addressing space, and we're just not at the point yet where even most enthusiasts are pushing that limit. Once applications begin to push the 2GB addressing space limitation of Win32 (something we expect to hit very soon with games) or total systems need more than 4GB of RAM, then Vista x64 in its current incarnation would be a good choice.
For some time now we have been mentioning the potential problems that are likely to result from the switchover from 32bit(x86) Windows to 64bit(x64) Windows. Due to a multitude of issues, including Windows' memory management, the basic design of the PC architecture, and consumer support issues, there is no easy path for mass migration from 32bit Windows to 64bit Windows. As a result we have been expecting problems as consumers begin to make the messy transition.
We published the above mentioned guide on February 1st, expecting the fall/winter 2007 games to be the ones to push the 2GB addressing space limitation of Windows, and it turns out we were wrong. It turns out that two weeks after we published the above article, THQ published Supreme Commander, a RTS with a massive appetite for resources. It can be simultaneously GPU limited and CPU limited, which is why it's a standard benchmark here for our performance articles, it's also memory limited in more than one way: it's hitting the 2GB barrier of 32bit Windows.
An artifact of the design of 32bit processors and the 32bit API for Windows, the 2GB barrier is a cap on how much addressing space (related to but not equivalent to memory usage) a single application can use. This isn't a bug but rather the result of how hardware and software was created so many years ago, and while everyone has known this barrier will inevitably be hit, as we'll see there are several reasons why it can't simply be moved or bypassed. Meanwhile hitting it involves affected applications crashing for what can appear to be no good reason, and understanding why the 2GB barrier exists and what can be done will be important for resolving those crashes.
On a personal note, I am a semi-casual player of real time strategy(RTS) games and I've been playing Supreme Commander lately. This is a different kind of article, it's a record and the result of my own efforts to resolve why I was having crashing issues with Supreme Commander. With no intended disrespect towards THQ or the game's developers (Gas Powered Games) we could have not possibly asked for a better example of the 2GB barrier in action. It's exactly the experience we believe many people will have as they hit the 2GB barrier, mainly those power users who use large monolithic applications such as games or multimedia tools. This is an article on what the problem with the 2GB barrier is, what kind of experiences a user may expect when hitting it, and what can be done to fix it.
But before we get too far ahead of ourselves, let's discuss memory management in Windows. Understanding the problem with Supreme Commander requires understanding what the 2GB barrier is, why it's there, and what makes it so problematic.
Facebook
Twitter
RSS
69 Comments
View All Comments
brink - Thursday, July 12, 2007 - link
it's a 2 prong solution for WinXP, you have to set a /3GB flag in your BOOT.INI file for the instance of windows you're booting. Additionally since Supcom doesn't have the LARGEADDRESSAWARE flag, you have to patch the EXE using the tool mentioned in the article ((someone created a batch that uses the tool to patch the supcom exe, easily found in the official supcom forums)I mention this since the article doesn't really say how they did it (and they used Vista, which is another boc to contend with) Since HardOCP did a comparison a while back between supcom perf in XP and Vista, I've really only installed/used supcom in XP still. With our fix for a 4GB machine (the machine I regularly use still has 2GB, I just stay away from 81KM maps) XP has still remained stable, but we did have one crash in a 40KM map game on Gentleman's Reef.
I don't like the article's preference on FPS in Supcom, mainly because I don't look at Supcom as a FPS centric game at all. If you've played, you know when a slow computer enters the game (or you have 7 computers each with 1,000 units on a 81KM map) the in-game timer will start to crawl. 1 second of game time will take 2 seconds, or much much worse. It would have been approx 100x cooler if the bench was "it took this much before the timer started to skew".
jay401 - Thursday, July 12, 2007 - link
lol funny, now that I am paging through the article I see you mention this very issue. Good!jay401 - Thursday, July 12, 2007 - link
Well you didn't address the 'WHY' - why the game uses so much memory. Hopefully I provided a little light on that subject.Also on Page 5 none of your graphs are labeled as to what they are measuring. Please note if they're measuring fps, which is my gut but I'm not sure because they are unlabeled.
Thanks.
MadBoris - Thursday, July 12, 2007 - link
Although you are right in part, the lead engineer did mention the units are one reason for large memory consumption. (BTW, I had heard that they are all being/were rerendered for November). There is another issue beyond that though that becomes obvious. The initial virtual address space at the beginning of a game between a 20k map and 81k map is only about 150MB difference. But as unit count climbs, the larger map gap grows somewhat exponentially compared to the smaller. So something else is askew.
As Ryan mentioned the whys and wherefores aren't really the point, this issue is a global one and 2GB is a real hard limit now for games since we have the horsepower(CPU & GPU) for larger memory consuming texture maps, larger resolutions, yet the 2GB memory limit for a game is a definitive roadblock to forward progress so I am glad the issue is coming to the forefront.
As much confusion and fear there is on this /3GB subject for the laymen, this is still a great rabbit in the hat for us with 32 bit OS's if more driver writers get on the ball, fears can subside. Hopefully devs like Crytek can continue to push demand for 64 bit with a nice 64 bit Crysis patch too, and we can start making the transition leaving 32 bit behind as drivers/apps also make the transition.
I think articles like these help the cause.
Ryan Smith - Thursday, July 12, 2007 - link
To be honest, we didn't address why because it really isn't relevant. Even if Supreme Commander was done perfectly in every way, the result would have been the same once it reached the 2GB barrier.gigahertz20 - Thursday, July 12, 2007 - link
They should have made Vista only 64 bit to put pressure on the transition.johnsonx - Friday, July 13, 2007 - link
The problem with going 64-bit only this time around is that there are too many 32-bit programs around that simply won't run on 64-bit windows. I have several myself that I depend on daily. They are slightly older programs that the developer doesn't intend to upgrade to be 64-bit, but that doesn't change the fact that I need them. If these apps didn't work with Vista because it was released in 64-bit only form, then I wouldn't be running Vista. Millions of others are (or would be) in this same situation, which would significantly harm Vista sales.If the next version of Windows were made 64-bit only, around the 2010 time frame, I think that would be quite reasonable. By then most 32-bit only programs will have been replaced or rendered obsolete.
I think Microsoft has handled the 32/64-bit issue correctly so far, for the most part. XP64 should have been ready sooner and should have been better supported though.
Related question for anyone who knows: I know retail Vistas include 32-bit and 64-bit on the same disc, and the user is free to install either. I also know that OEM Vistas include only the one version on the disc. What about the OEM keycodes though? Can you install a 64-bit Vista using the keycode that came with a 32-bit disc? Or has MS limited the keycode as well?
StygianAgenda - Thursday, June 5, 2008 - link
To answer your question about the Windows Vista Retail package, I have 2 copies of Vista Ultimate retail, and it was packed with 2 DVDs, 1 is 32bit, the other is the 64bit build.The set comes with a single key, and the key is bound to the 64bit version, so if you opt to use the 32bit version instead, you'll most likely have to call into Microsoft's activation center and manually activate your copy. I've had to do this 4 times now, due to hardware changes, because Vista detects system changes, so if you remove 1 or 2 boards and boot into Vista, the system will automatically de-activate. Now, granted, the call to MS was fairly painless, but it's annoying all the same.
Out of the 4 Vista systems I own currently (3 of which are laptops), I've had great success with the OS, itself. Unfortunately for me, the motherboard I've been using on my custom built workstation is flaky... I've done my research though (tonight), and might have a fix in the works, if it works, that is. Otherwise, I'll be ordering a new motherboard, and calling Microsoft yet again to transfer my license to the new configuration. By the way, they always ask "Is this copy running on more than one PC?". In light of all the hoopla over the licensing scheme in Vista, I would hope that no one is stupid enough to try to use a Vista Retail license on multiple PCs, because it'll cause all of them to be blacklisted. Oh, and the new Vista Enterprise edition is only available in lots of 25 licenses or higher, and requires a licensing server on the LAN with the deployed workstation licenses. It's either that, or expect to have a couple of extra hundred MB or so of net traffic from all of the Vista Ent. workstations checking in with MS everytime the systems are booted. Makes me glad that I also work with Linux very heavily, and all things considered, if Linux + WINE can run all of my criticle Win32 apps, then this will be the last Vista Licenses that I buy. I'll still keep Vista on my laptops, and I'll continue to run my XP workstations, and 2K3 servers, but MS is going to have to really do some impressive work to get me convinced to migrate to their next platform... such as maybe... a *real* 3D desktop... which is already available, stable and totally badass on Linux (check out Kubuntu + compiz).
(btw: Sorry if I seem like I'm on a rant here... no offense intended toward the readers, at all... it's just that when you work with OS's at the level that I do, after a while stupid mistakes made by OS vendors start to get beyond aggrivating.)
instant - Saturday, July 21, 2007 - link
And when we are talking about GAMES, how if at all is this relevant to the current discussion?x64 has been the way to go ever since it was released.
miahallen - Saturday, July 14, 2007 - link
That is incorrect, Vista x64 will run x86 apps without problem (so will XP x64), that's the nice thing about it. I ran x64 for quite a while, and ran almost nothing but x86 apps on it.The keycodes for x86 do not chnge for x64 installs...they use the same key. And the retail versions I bought did not have both versions on one disc, I had to order a x64 disc online (and pay $10 for S&H).