WinXP 32bit with 4g ram???will it work

[cuti7399]

I have winxp 32bit right now and have extra 2gig of DDR1. I'm not quite ready to upgrade to vista yet because there are some of my hardware that does not quite support vista yet. Will I have problem putting the extra 2gig in there? I read that winxp 32bit will only recognize 3gb!Any help/input is appreciated

 

[Yellowbeard]

In short you are correct, XP will not be able to fully utilize 4gb of memory. Most likely if you install 4gb, your system will "see" about 3.2gb of the installed system memory. If your MOBO runs 4gb this is not an issue.

As for installing the extra 2gb of memory, the only way to know if it will work is to install and test. You may have to change some timings or voltages manually, it depends on the board and the bios.

 

[JustaGeek]

You have to activate /3GB switch in boot.ini file, and that's the maximum the system will ever use (cosidering that you have applications able to use RAM beyond 2GB - 99% of all programs were designed for maximum of 2GB RAM).

Between 3GB and 4GB the memory is reserved for the system - Video, chipsets etc. Under normal circumstances, without the /3GB switch active, system reserves the memory between 2GB and 4GB.

I added 1GB to my 2GB because Quake 4 on Ultra Quality settings was "jittery" and running 99% of my 2GB RAM.

It shows 64% use now, consistent with the 2GB upper limit, but... it is smoother, so perhaps XP uses that extra memory in lieu of the paging file.

 

[pallejr]

The /3G switch has little to do with addressing physical memory. It is about the layout of the virtual memory space, not the physical

 

[JustaGeek]

Originally posted by: pallejr
The /3G switch has little to do with addressing physical memory. It is about the layout of the virtual memory space, not the physical

Could you elaborate?

Without that switch activated, an application will not even attempt to go beyond 2GB (assuming it is designed for more than 2GB.)

From what I have learned, there is only a handful of applications that might be able to take advantage of that.

Now - the physical part. Even if you install 4GB, that is an upper limit of 32 bit OS. By default, the 32 bit OS will assign 2GB for applications (user) and 2GB for the system, including Video, chipsets, etc.

In short - when you install 4GB, you will effectively have >4.5GB of RAM to be addressed by the system, if you have a Video Card with 512MB Video Memory. And that is impossible, and kinda useless in a 32 bit OS.

3GB of physical with the /3GB switch might make sense - again, if your applications can take advantage of 3GB RAM.

 

[pallejr]

Each application has its own private user space. So 10 processes could potentially use 20GB.

The /3GB switch can be useful, if you have a very memory-hungry application, that has the large_address_ware flag set in its image header. Visual studio has the editbin tool, that you can use to set the flag yourself. No special APIs are needed to take advantage of this

MMIO is not mapped into the virtual memory space. This belongs to the physical address space

 

[JustaGeek]

Are you saying that even if the 32 bit OS cannot see the 4GB of RAM, only 3.2GB or so because of the other on-board memory, it will somewhat/somehow use it...?

The original question was (in my words) - can I take advantage of 4GB of RAM in a 32 bit OS?

Please let us know if 4GB RAM makes sense at all in a 32 bit OS.

 

[Yellowbeard]

Originally posted by: JustaGeekThe original question was (in my words) - can I take advantage of 4GB of RAM in a 32 bit OS?

Please let us know if 4GB RAM makes sense at all in a 32 bit OS.

You will NOT be able to fully use all 4gb of installed system memory with a 32 bit OS, PERIOD.

However, with a 4gb kit, you may see as much as 3.5gb or more depending on your other installed hardware. Memory is dirt cheap these days so IMO, it does make sense to buy 4gb as you can avoid lots of other issues by having matched DIMMs. And, the aforementioned 3.2gb or so of memory is still a 50% increase so that can't be a bad thing.

 

[JustaGeek]

Originally posted by: Yellowbeard

Originally posted by: JustaGeekThe original question was (in my words) - can I take advantage of 4GB of RAM in a 32 bit OS?

Please let us know if 4GB RAM makes sense at all in a 32 bit OS.

You will NOT be able to fully use all 4gb of installed system memory with a 32 bit OS, PERIOD.

However, with a 4gb kit, you may see as much as 3.5gb or more depending on your other installed hardware. Memory is dirt cheap these days so IMO, it does make sense to buy 4gb as you can avoid lots of other issues by having matched DIMMs. And, the aforementioned 3.2gb or so of memory is still a 50% increase so that can't be a bad thing.

That's exactly what I have learned.

I went with 3GB RAM total to avoid the >3GB problems on my particular MB, and IMO it would not make sense to have that "overage" just "sit" there useless. It was a little less expensive to buy 2x512MB modules, too, and I am planning to use my XP for at least another year.

And /3GB switch must be activated for the applications, if they are designed to use the space >2GB.

 

[pallejr]

About the /3GB. I'm not sure you got it right. If you have more than one processe running, they won't have any problem using all the visible RAM (3.x GB).

Only if a special application needs to work with more than 2GB, is the switch needed.

And then there are all the special stuff (not much relevant on desktop Windows). Like PAE and AWE. With this stuff you can go way beyond 4GB (if the hardware also supports it).

 

[Yellowbeard]

It was a little less expensive to buy 2x512MB modules, too, and I am planning to use my XP for at least another year.

My main issue with this is that it is never a good idea to mix different ICs or different speeds/densities/types etc of memory. In some cases you get compatibility issues. However, there is no guarantee.

If your mix does work that's cool and as you said, you are not allowing approximately 1gb of memory to sit unused. But, I just answered a post on another forum and a guy stated he was getting two 2 x 1gb kits of our PC6400 for $79 each. I cannot imagine a 2 x 512 kit being substantially cheaper than that so, the safest route is to go for the 4gb and avoid the potential issues.

 

[JustaGeek]

Originally posted by: pallejr
About the /3GB. I'm not sure you got it right. If you have more than one processe running, they won't have any problem using all the visible RAM (3.x GB).

Only if a special application needs to work with more than 2GB, is the switch needed.

And then there are all the special stuff (not much relevant on desktop Windows). Like PAE and AWE. With this stuff you can go way beyond 4GB (if the hardware also supports it).

My Logitech G15 keyboard software would would show 99% RAM use while playing Quake 4 on Ultra Quality settings (uncompressed textures), and I would experience a "jittery" performance.

With the additional 1GB, for a total of 3GB, the same software would show ~65%, consistent with the 2GB upper limit for the applications. I guess Quake 4 is not designed to go beyond 2GB, but the performance improved!

Perhaps the system uses that space instead of Swap file on the Hard Drive.

I do not have any other application to take advantage of >2GB, but the /3GB switch in the boot.ini file will not hurt anything. If/when I need it, it will be there.

 

[JustaGeek]

Originally posted by: Yellowbeard

It was a little less expensive to buy 2x512MB modules, too, and I am planning to use my XP for at least another year.

My main issue with this is that it is never a good idea to mix different ICs or different speeds/densities/types etc of memory. In some cases you get compatibility issues. However, there is no guarantee.

If your mix does work that's cool and as you said, you are not allowing approximately 1gb of memory to sit unused. But, I just answered a post on another forum and a guy stated he was getting two 2 x 1gb kits of our PC6400 for $79 each. I cannot imagine a 2 x 512 kit being substantially cheaper than that so, the safest route is to go for the 4gb and avoid the potential issues.

You are absolutely right - that's why I did not mix, using HZ memory modules with Micron chips from G.Skill (4-4-4-12-2T, 2.0V - 2.1V)

2x1GBHZ was ~$110 at the time (it is now ~$130), and my 2x512MBHZ was ~$70.

And my motherboard has known issues with 4 memory modules installed, that's why I tried to (at least) avoid the addressing problems of >3GB.

 

[Yellowbeard]

Good move on mixing the Microns for sure. Too many people don't consider that or, they think about it only after finding a good price.

Just curious, I have a P5N-E SLI and I ran 2 different sets of 4 x 1gb Dominator DIMMs (Corsair PC6400 Promos based and also Corsair 8888 Micron based). They ran fine and I was even able to OC the memory some. Where have you seen this "known issue"?

 

[JustaGeek]

Originally posted by: Yellowbeard
Good move on mixing the Microns for sure. Too many people don't consider that or, they think about it only after finding a good price.

Just curious, I have a P5N-E SLI and I ran 2 different sets of 4 x 1gb Dominator DIMMs (Corsair PC6400 Promos based and also Corsair 8888 Micron based). They ran fine and I was even able to OC the memory some. Where have you seen this "known issue"?

Well... Where do I start LOL?

Long story short - I was perfectly stable for over 6 months, and finally decided to update the BIOS from 0202 to 0608. Many people on the anandtech forum:

http://forums.anandtech.com/me...AR_FORUMVIEWTMP=Linear

and asus forum:

http://vip.asus.com/forum/topi...%20SLI&SLanguage=en-us

would report problems with more than 2 sticks of RAM installed.

The solutions that would help some people involved raising the NBCore voltage to ~1.58V, booting with 2 sticks, and only after all the BIOS manual adjustments adding the remaining 2 etc.

I am still struggling with the cold boot issue. Am running out of options, and all my memory settings were recommended by a G.Skill technician.

It will just stop at POST screen ofter displaying the processor and the clock, just before the memory check. I have to hit reset to re-POST (the clock stays at 2.92GHz, so the problem is not the overclock), and then it (usually) continues.

Memtest and Orthos stable, no BSOD's, perfectly fine and fast in Windows.

Only that cold boot, sometimes re-boot issue. I think it has something to do with the new C6 microcode for C2D CPU's. The previous one was 44, and I had no problems.

Also, the temp sensor calibration. I have 2 E6600 CPU's, one purchased in September 2006, one in April 2007.

The "September" idles at 39C CPU, 45C Core 1/2, the "April" 32C CPU, 28C Core1/2.

IMHO, it is impossible for the core temps to be lower than TJunction, so it must be the temp sensor calibration issue...

 

[JAG87]

There are issues with 4 sticks installed. 680i reference board has trouble handling 4 dimms. I have experienced this with four OCZ PC-8500 SLI sticks, which is a real shame. I have tried both kits seperately and they work great, but all 4 together have issues. And the funny thing is that you will not see these issues right away, you have to use specific software that is memory sensitive.

I guess you will be happy to hear that I am going to put my 2 sticks of Corsair 6400C3 memory back in there. Im just sad that I cannot find any 6400C3 XMS memory anymore so I can try running 4x1 of that stuff.

I always wanted to ask you, why did you guys stop making the 6400C3 XMS memory, and only make the 6400C3DF. As much as the dominator heatspreader is good, it severely hurts my temperatures since it creates a wall that interferes with my front to back push pull airflow. Its like having the great wall of china in the middle of your motherboard :laugh:

 

[JustaGeek]

Yup, the 650i is the same chip as the 680i, with some features disabled.

 

[Yellowbeard]

I have no idea why we don't make the standard XMS C3 now. Marketing is as marketing does and all the good Micron stuff is Dominator now as you noted. I think mainly they are just pushing Dominator as the high end stuff which the 6400C3 certainly is.

I ran a Swiftech NB cooler on my P5N-E SLI before I water cooled it. It was HOT as fire but, as you noted, you have to go over 1.53 or whatever on the NBv to get stable with much of an OC and/or 4 DIMMs. But, it was stable on air or water and I never had any 4 DIMM issues. Oddly enough, I have a 2 x 2gb kit in that rig now and I still have to run 1.53v NBv to keep my OC stable, FSB 1600 at 1:1. I had hoped to be able to drop that 1 notch with 2 DIMMs. I have also not had the cold boot issue. Perhaps I got lucky though. I won't claim any particular skill in that.

 

[JustaGeek]

I measured the temperatures with an Infrared Thermometer from Harbor Freight Tools (!?!).

Northbridge air cooled with stock HSF is ~46C, Southbridge was 62C bare (!!!), ~52C with the CompUSA heatsink, ~40C with the added CompUSA small fan.

For the air cooled systems, I strongly believe in the CPU HSF's blowing on the processor - they help cool the components around the CPU tremendously, IMHO.

BTW, it is great to see the RAM professional on this forum - thank you!

 

[Yellowbeard]

Originally posted by: JustaGeek


BTW, it is great to see the RAM professional on this forum - thank you!

Thanks man I appreciate the welcome, and I am happy to be here. This is a good forum and I like to meet up with other enthusiasts that have a different perspective on things. I learned something here about these boards and I'll keep my eyes open for more of those P5N-E issues. It's easy to overlook stuff like that when I am so busy.

L8R.

 

[NoobyDoo]

Check out this : Ask Dan: What's with the 3Gb memory barrier? .

Apparently, using between 3GB and 4GB of memory isn't very smart - irrespective of whether you use XP or Vista, or whether you use 32-bit or 64-bit versions of Windows.

That is, use 3GB or less, or use more than 4GB (for a 64-bit version).

That's what I understood, anyway. Correct me if I'm wrong.

 

[pallejr]

You will not break anything by installing 4GB. Some of it will just sit there doing nothing. If you use a lot of RAM, 3.x might be slightly better than 3.0

4GB and 64-bit will work just fine, with memory remapping enabled.

 

[myocardia]

More in-depth discussion on this topic. Don't you guys read the front page?

 

[JustaGeek]

It is a strange coincidence with the article, but I have just experienced strange crashes, freezes and other "weird" behavior of the computer, resulting in having to use the power button to shut down the machine while playing "Far Cry".

It really seemed like the Video driver was "fighting" for space with some game files, since even during initial loading the game would show strange artifacts and open in "Windowed" mode. When I tried to change it to "Full Screen", the game turned to black screen.
Ctrl-Alt-Del would expose weird pulsating screen with the desktop icons flickering, unresponsive to keyboard or a mouse. Hard shutdown was an only option.

As a result, I decided to REMOVE THE 2x512MB RAM modules, leaving only 2GB in the system. The problems disappeared.

As it turns out, 3GB RAM, even with the boot.ini switch activated, did not make sense. The problems were only waiting to happen - and they did...

UPDATE: Decided to re-install the 2x512MB sticks, but not to enable /3GB switch. Will see if it works... At least the system will hopefully use its 2GB more efficiently...

 

[0roo0roo]

http://www.dansdata.com/askdan00015.htm