Windows Vista vs Windows XP

[Chalenge]

It has also been reported that even under Windows 2003 the /pae switch is unstable and presents more overhead then its worth (hindering any performance boost gained). Your argument that XP is 30% faster is untrue. It might have a 13% advantage in best case scenarios but for most users that translates to perhaps 1-3 fps.

At any rate the maximum memory any 32 bit OS can address even with the large memory address switches active is 3GB. On a 32 bit OS that means that with the OS able to 'discover' 3.5 GB and the OS squeezed into just 1 GB that the most any app (if the only one running) is 2.5 GB. With more then a single app running it has to share that memory and then the OS quickly starts resorting to swap/page filing and system performance starts to drop (perhaps only a little).

I am not a programmer and I cant tell you if any 32 bit app can or cannot address more then 2 GB of memory. I can only say that in my experience on machines with plenty of extra RAM that system performance almost never drops (I have seen some cases where IE or explorer.exe refuses to let go of resources even on XP). It would seem reasonable that an app designed to run on windows makes use of swap/page file and every other performance tool of windows since it is running under that OS. By giving an app unconstrained memory space you are limiting the potential for memory crashing which is something I do have experience with (on XP 32). Also in addressing large memory addresses while using high definition resolutions the potential for memory overruns is increased on any 32 bit OS. I had experienced all of this before deciding I wanted more RAM then XP 32 bit could offer. I considered XP 64 bit and found it too expensive compared to Vista Ultimate.

I discovered all of this on the web over the course of a months research before purchasing any of the elements of my current system. As I suggested earlier I recommend that anyone do the same thing. If they come to the conclusion that they must have the ability to make use of large memory addressing (64 bit) and wish to stay in the Windows family they will save money with Vista. XP Pro 64 bit was and still is over $300.

I also disagree with Kev that the ONLY reason for Vista is DX10 for reasons I just outlined.

[Skuzzy]

Just some facts.

32 bit addressing gives 4GB of direct addressable RAM.  Intel CPU's have never had a flat memory model.  Even with 4GB of addressable space, it is still using an index register just like the old 16bit days.  PAE extended the index register itself to allow more indices's with each segment being 4GB long and added 4 extra bits to the address/segment register (36 bit).

From a hardware perspective, it is not any more inefficient than the using the current single 4GB segment.

However, Microsoft's memory management is atrocious, thus leading some to believe PAE is the issue.  Fact of the matter is, UNIX's have been using PAE for years before Microsoft and have never suffered a performance issue when using it.  Only Microsoft operating system's suffer.  Microsoft is also the one who arbitrarily limits how much RAM thier OS's will address, regardless of what the hardware is capable of.

With PAE, there is only one additional look-up (always an internal CPU cache hit) performed when it is enabled in the CPU, and that look-up occurs during time when RAM cannot be addressed.  Due to the way it works, it will not have any visible impact on performance, from the hardware level.

Now PAE still does not allow an application to run outside of a single 4GB segment.  Meaning the application still only has 4GB of RAM, at most, to use.

[MrRiplEy[H]]

There's an interesting article about this here:

32-bit Memory in x64 Windows
Published 18 March 8 8:55 AM | Charlie Russel

In the public 64-bit Windows newsgroup, we often get questions about memory usage, and a recent post there made me realize that there are some basic misunderstandings about the relationship between memory, virtual memory address space, and RAM.

32-bit Windows uses a flat memory address space, thus is limited to 4 GB of memory addresses. This is divided up 2 GB for individual user programs, and 2 GB for the operating system. It doesn't matter if you have 4 GB of RAM, or 512 Mb of RAM, it's the same virtual memory address space. This means that in order to directly address the memory used by video cards, and other such things on your computer, the OS has to be assign those specific addresses to that memory, and it's locked away and can't be seen - effectively making your memory address space smaller. But each user program that runs gets its own 2 GB of virtual memory address space, regardless of the RAM in your machine.

[Chalenge]

Interesting how you quoted that but cut it short of the 64 bit part:

In 64-bit Windows, the memory address space is 16 TB. 8TB for user programs and 8TB for the operating system. 32-bit programs running in 64-bit Windows run in the WOW64 subsystem. Each 32-bit program is assigned a 4 GB virtual memory address space in the WOW64 subsystem - with no requirement for the OS which is still running in the 8 TB of virtual memory address space it gets.
So, if your 32-bit program is written to take advantage of >2GB of memory (using the LARGEMEMORYADDRESSAWARE compiler switch), it will automatically see a full 4GB.

[MrRiplEy[H]]

Interesting how you quoted that but cut it short of the 64 bit part:

Note the big 'if' there. Most 32-bit apps are designed to be run in standard 32-bit OS.

[Kev367th]

@Chalenge

Irrespective of whether PAE causes instability or performance drops I used it as an example that 32 bit Microsoft 'Home Use' OS'es are not limited to 4Gb by hardware, but by an arbitrary limit chosen by Microsoft.

As for Vista -
It's the biggest piece of bloatware MS has EVER released.
Its slow penetration into the market has even dissapointed MS.
Dell has so many problems with it they STILL offer XP as an alternative on a lot of systems.
DRM in it is intrusive, no way to turn it off.
Incompatilities with existing software, especially those that access ring 0.

As a sytems administrator for a company, I will not recommend or buy any system with Vista on it.
If there is no alternative the first thing I do is to reformat and install XP.

Would be willing to bet that if MS had not withdrawn XP from general sale it would still be the OS of choice over Vista.

[Chalenge]

@Kev

Agreed on most counts and still Vista 64 satisfies my needs for a system without spending twice the cash! Everything you said has been stated before and I will stick by my guns in repeating... If you need a larger memory frame ...

Obviously you dont have to use 64 bit apps to get where you are going. There are people that do. Perhaps I am the only one that does and is playing AH but I wouldnt lay odds on it.

[MrRiplEy[H]]

@Kev

Agreed on most counts and still Vista 64 satisfies my needs for a system without spending twice the cash! Everything you said has been stated before and I will stick by my guns in repeating... If you need a larger memory frame ...

Obviously you dont have to use 64 bit apps to get where you are going. There are people that do. Perhaps I am the only one that does and is playing AH but I wouldnt lay odds on it.

64-bits is cool if you happen to be one of the professional users who need uncommonly huge amounts of memory. For general home use it's still more trouble than anything else. I expect to move to 64 bits in 2-4 years timeframe when both hardware and software support gets matured.

[Bino]

All this back-and-forth reminds me of something Randy Pausch said, "the plural of anecdote is not data".

[boatman]

 You guys are scaring me. I have a new system coming.
 AMD Athlon 64x2 2.6, 2000MHz FSB
 Amd 790x Phenom Spider platform
 2GB Kingston DDR2 800 MHz mem
 320BG S-ATA 7200RPM hard drives
 ATI Radeon HD4850 512MB ddr3 625MHz
 Vista home basic 32bit

 Got it so I could join AH but is it going to run it?
 

[Skuzzy]

The hardware is not a problem boatman.  More than adequate to run the game at good detail levels.  It just takes a little work tweaking Vista to get it to run the game smoothly.

You will have to run the game in "Windows 98/ME" compatibility mode due to the high resolution timer bug in the AMD multi-core family.

[boatman]

Thanks Skuzzy. Hope to have it next week. See ya then.

[MrRiplEy[H]]

The bug affects also Intel motherboards with AMD 690 chipsets.