Basic Memory FAQs

[trooper1947]

For all new or not knowing it needs the basics of memory guide .

1. All 32 bit OS systems will only show and use 3 gigs of memory ... no matter what anyone tells you !
2. Check your MB specs first to see what memory to install for speed in mhz. and compatability .
3. Yes 3 gb of memory will help your system as windows uses around 1 gig to operate . Verified in system info . Leaving 2 gb to run games and programs without using SLOW virtual memory.
4. You must use dual sticks of dual memory to get dual operation . 1 huge stick will NOT run dual !
5. Almost all games and programs at the present time are designed to run on maximum 2 gigs ... BUT this may not or will not be fact for future software most likely.
6. 64 bit OS will not give you any advantage unless you are using 64 bit software
7. MICROSOFT lies about memory useage and capabilities for Vista !
8. Check compatability and reliability of memory brand first !
9. Don't mismatch memory if possible ... it may even slow or crash your system if incompatable.
10. Amount of video ram/memory is important to a degree but adapter hardware can determine full and more full useage of what adapter/card has . Check the benchmarks section here for the real tests and lowdown before overbuying a video adapter.
11. Bios will show alot more memory than windows on most systems but windows will not recognize or use it ! 32 bit OS ....

If anything here is wrong please advise me and I will edit it ... I'm just trying to help all these people who waste time and money with all kinds of problems repeated in this forum .

 

[CompTIA_Rep]

Can you re-subject the post to read:

Basic Memory FAQs. Then someone should sticky it.

 

[trooper1947]

done ........... thanks

 

[celewign]

How kind of you.
-cm

 

[Mondoman]

...
1. All 32 bit OS systems will only show and use 3 gigs of memory ... no matter what anyone tells you !

More Details: It's really WinXP and 32-bit Vista that have the 4GB address count limit ("server-type" 32-bit versions of Windows and at least some 32bit Linux distros use special hardware and software extensions to somewhat expand that limit. However, software needs to be specially designed to use these extensions w/o problems, so for compatibility and performance reasons, Win XP and 32 Vista don't use the extensions to allow more than 4GB of address space).
The "3 gigs" is just a rough average; the specific limit for your system depends on the specific hardware installed, but may be less than 3GB, or may be up to 3.5-3.75GB.
The reason that Windows can only "see" (and thus use) less than 4GB is that it is limited to 4GB of memory space addresses, but some of the hardware in the system uses up some of those addresses for e.g. memory-mapped I/O. Whatever is left over after that is what is available for the physical RAM in your system, and thus determines the amount of RAM Windows sees and uses.

...2. Check your MB specs first to see what memory to install for speed in mhz. and compatability .

This is not really helpful, as it doesn't take into account matching memory throughput to the CPU and doesn't take into account OCing the CPU, MB, or RAM.

...3. Yes 3 gb of memory will help your system as windows uses around 1 gig to operate . Verified in system info . Leaving 2 gb to run games and programs without using SLOW virtual memory.

More details: These again are rough averages; however, given the sizes of modern apps, just about every Windows computer running multiple apps simultaneously will benefit from going to 3GB RAM.

...4. You must use dual sticks of dual memory to get dual operation . 1 huge stick will NOT run dual !

Let's correct/improve this to read: 4. You must use at least one stick (module) of memory *per channel* to run the memory in dual-channel mode. Not all MBs allow dual-channel mode; those that do usually have specific requirements for the number/makeup of the DIMM modules in order to run in dual-channel mode -- see your MB manual for details. Recent Intel chipsets are very flexible in their requirements for running in dual-channel mode.

...5. Almost all games and programs at the present time are designed to run on maximum 2 gigs ... BUT this may not or will not be fact for future software most likely.

Let's correct/improve this to read: 5. 2GB total system RAM is plenty for almost any Windows app/game. Since current 32-bit Win XP and 32-bit Vista can in practice only handle about 1-1.5GB more RAM (3-3.5GB total), future Win software that requires more RAM will most likely run mainly/only on 64-bit Vista.

...6. 64 bit OS will not give you any advantage unless you are using 64 bit software

Let's correct/improve this to read: 6. On its own, 64-bit Vista will not run your current 32-bit software any faster, and will perhaps run it more slowly due to driver/other issues. However, given a recent CPU/MB, 64-bit Vista will be able to use more than about 3GB of RAM, which may very well improve multitasking performance, as your apps would not have to swap to virtual (hard disk) memory as often.

...7. MICROSOFT lies about memory useage and capabilities for Vista !

Let's correct/improve this to read: 7. Microsoft's recommended minimum hardware configurations for running its OSes are typically *dramatic* underestimates of what you will need for good performance. For example, 1GB (unshared) system RAM is a realistic minimum for Win XP, and 2GB is a realistic minimum for Vista.

8. Check compatability and reliability of memory brand first !

Let's add: Don't confuse the quality and performance of "value" lines such as ValueSelect, ValueRAM, etc with the main or premium lines of memory by the same manufacturer.

9. Don't mismatch memory if possible ... it may even slow or crash your system if incompatable.

Let's add: However, since memory module designs/components change almost weekly, you often may have to mix modules. Higher-quality modules are less likely to have incompatibility problems than lower-quality modules; also, certain brands' premium lines are known for compatibility, others are known for performance, and some are known for both, so decide what aspect is most important to you before choosing what to buy.

10. Amount of video ram/memory is important to a degree but adapter hardware can determine full and more full useage of what adapter/card has . Check the benchmarks section here for the real tests and lowdown before overbuying a video adapter.

Since video cards are discussed in another Forum section, let's remove this.

11. Bios will show alot more memory than windows on most systems but windows will not recognize or use it ! 32 bit OS ....

Let's improve this to read: 11. At bootup, the BIOS will typically quickly test and show the total amount of physical RAM installed. However, this normally takes place before the various hardware components are assigned their memory addresses, and so the actual amount of physical RAM "visible" to 32-bit Windows may be less if you have more than 2GB of RAM installed.

 

[celewign]

Ouch...

Poor Trooper.
-cm

 

[Mondoman]

Another point:
x. Points to check in choosing the right type of RAM for your system:
a. Does it take DDR or DDR2? These have different numbers of pins and physically will not fit in each other's slots. A few "Frankenstein" MBs have slots for both types, but will only allow one type of RAM to be installed at a time.
b. Does it take unbuffered, registered, or fully-buffered RAM? Essentially all desktop MBs we deal with here take *only* unbuffered RAM (the other types are typically used in servers).
c. Does it take "normal" or ECC RAM? Most desktop MBs take only the typical "normal" (non-ECC) RAM, but some will also accept *unbuffered* ECC RAM (although they may or may not make use of the ECC feature). Note that almost all server RAM is ECC *and* registered or fully-buffered, so almost all RAM described as "ECC" will NOT work on normal MBs that require unbuffered RAM.
d. Faster RAM can always be run at a slower speed. Thus, if you see a good deal on DDR2-800, but only plan on running it at DDR2-533 speed, you'll be fine.
e. A Faster MB memory bus can always be run at a slower speed. Thus, if you see a MB with a DDR2-800 memory bus, the bus can always be run more slowly to accomodate e.g. DDR2-533 RAM.
f. Much DDR2-800 and faster "premium" RAM is advertised according to a factory-sanctioned overclock speed spec requiring a voltage boost above the standard DDR2 1.8V. In these cases, the actual (slower) speed when run under standard DDR2 1.8V conditions is rarely disclosed. Watch out for this widespread deceptive practice among memory manufacturers.

 

[Mondoman]

Ouch...

Poor Trooper.
-cm

Not at all - I salute Trooper for taking the initiative to help out the many newbies here!

 

[celewign]

Yeah. I know. You know what I mean.
-cm

 

[carver_g]

3. Yes 3 gb of memory will help your system as windows uses around 1 gig to operate . Verified in system info . Leaving 2 gb to run games and programs without using SLOW virtual memory.

1 gig or RAM just for the Vista OS is close enough. 1 gig just for the XP OS is high. After doing a clean install, XP Pro SP2 uses about 200MB on its own. Add on Antivirus and other basics and you will be around 300MB of RAM for XP and basic add-ins.

Great that you have spearheaded this guide!

 

[celewign]

Are you talking about RAM here?...

Ok, you are. Without at least 512 megs of RAM XP is slow - but anything over that amount will run XP just fine with a reasonable number of processes running. This lappy I'm on has 512 megs of RAM and I'm running Firefox x3, iTunes, Google updater, and a torrent downloader (!).
-cm

 

[Mondoman]

OK, here's the list w/mods incorporated:

1. 32 bit consumer Windows OS systems will only show and use roughly 3-3.5 gigs of memory even if more is installed.

Details: It's really WinXP and 32-bit Vista that have the 4GB address count limit ("server-type" 32-bit versions of Windows and at least some 32bit Linux distros use special hardware and software extensions to somewhat expand that limit. However, software needs to be specially designed to use these extensions w/o problems, so for compatibility and performance reasons, Win XP and 32 Vista don't use the extensions to allow more than 4GB of address space).

The "3 gigs" is just a rough average; the specific limit for your system depends on the specific hardware installed, but may be less than 3GB, or may be up to 3.5-3.75GB.

The reason that Windows can only "see" (and thus use) less than 4GB is that it is limited to 4GB of memory space addresses, but some of the hardware in the system uses up some of those addresses for e.g. memory-mapped I/O. Whatever is left over after that is what is available for the physical RAM in your system, and thus determines the amount of RAM Windows sees and uses.

2. Microsoft's recommended minimum hardware configurations for running its OSes are typically *dramatic* underestimates of what you will need for good performance. For example, 1GB (unshared) system RAM is a realistic minimum for Win XP, and 2GB is a realistic minimum for Vista.

3. 2GB total system RAM is plenty for almost any Windows app/game. Since current 32-bit Win XP and 32-bit Vista can in practice only handle about 1-1.5GB more RAM (3-3.5GB total), future Win software that requires more RAM will most likely run mainly/only on 64-bit Vista.

4. Yes 3 gb of memory will normally help your system's responsiveness as WinXP uses around 512MB to operate, while 32bit Vista uses around 1GB. More installed RAM allows Windows to use more RAM for performance improvement (e.g. disk caching) as well as to keep more user app components in (fast) RAM instead of (slow) virtual/hard disk memory. These again are rough averages; however, given the sizes of modern apps, just about every Windows computer running multiple apps simultaneously will benefit from going to 3GB RAM.

5. You must use at least one stick (module) of memory *per channel* to run the memory in dual-channel mode. Usually, that means you will install one or two "pretty much identical" pairs of modules. Your MB manual will tell you which slots to install them in for dual-channel mode (yes, it does make a difference).

Not all MBs allow dual-channel mode; those that do usually have specific requirements for the number/makeup of the DIMM modules in order to run in dual-channel mode -- see your MB manual for details. Recent Intel chipsets are very flexible in their requirements for running in dual-channel mode.

Memory DIMMs sold in "dual channel kits" are physically no different from DIMMs sold individually - you are just guaranteed that they are as close to identical twins as possible, and that they have successfully run in dual-channel mode on the manufacturer's test system. This may provide a small amount of extra reassurance to the buyer; however, note that if there is a problem with one DIMM in a kit, the manufacturer will normally require *both* to be returned for warranty replacement, potentially leaving you without any memory during the RMA process.

6. On its own, 64-bit Vista will not run your current 32-bit software any faster, and will perhaps run it more slowly due to driver/other issues. However, given a recent CPU/MB, 64-bit Vista will be able to use more than about 3GB of RAM, which may very well improve multitasking performance, as your apps would not have to swap to virtual (hard disk) memory as often.

7. Check compatability and reliability of the memory brand and line first! Don't confuse the quality and performance of "value" lines such as ValueSelect, ValueRAM, etc with the main or premium lines of memory by the same manufacturer.

8. Don't mismatch memory if possible ... it may even slow or crash your system if incompatible (although this is relatively rare). However, since memory module designs/components change almost weekly, you often may have to mix modules. Higher-quality modules are less likely to have incompatibility problems than lower-quality modules; also, certain brands' premium lines are known for compatibility, others are known for performance, and some are known for both, so decide what aspect is most important to you before choosing what to buy.

9. At bootup, the BIOS will typically quickly test and show the total amount of physical RAM installed. However, this normally takes place before the various hardware components are assigned their memory addresses, and so the actual amount of physical RAM "visible" to 32-bit Windows may be less if you have more than 2GB of RAM installed (see point 1).

10. Points to check in choosing the right type of RAM for your system:
a. Does it take DDR or DDR2? These have different numbers of pins and physically will not fit in each other's slots. A few "Frankenstein" MBs have slots for both types, but will only allow one type of RAM to be installed at a time. AMD socket 939 systems take DDR memory, while AMD socket AM2 systems take DDR2 memory. Intel Core2Duo systems take DDR2.
b. Does it take unbuffered, registered, or fully-buffered RAM? Essentially all desktop MBs we deal with here take *only* unbuffered RAM (the other types are typically used in servers).
c. Does it take "normal" or ECC RAM? Most desktop MBs take only the typical "normal" (non-ECC) RAM, but some will also accept *unbuffered* ECC RAM (although they may or may not make use of the ECC feature). Note that almost all server RAM is ECC *and* registered or fully-buffered, so almost all RAM described as "ECC" will NOT work on normal MBs that require unbuffered RAM.
d. Faster RAM can always be run at a slower speed. Thus, if you see a good deal on DDR2-800, but only plan on running it at DDR2-533 speed, you'll be fine.
e. A Faster MB memory bus can always be run at a slower speed. Thus, if you see a MB with a DDR2-800 memory bus, the bus can always be run more slowly to accomodate e.g. DDR2-533 RAM.
f. Much DDR2-800 and faster "premium" RAM is advertised according to a factory-sanctioned overclock speed spec requiring a voltage boost above the standard DDR2 1.8V. In these cases, the actual (slower) speed when run under standard DDR2 1.8V conditions is rarely disclosed. Watch out for this widespread deceptive practice among memory manufacturers.

Edit: reordered some points to group by subject better.
Edit2: changed point 5 a bit.
Edit3: added more info to 10a.

 

[trooper1947]

Poor me ? .... as I said they must check all specs on the MB to see what ram is functional ! Most new users who don't know squat about all the technical jargon you gave out will be lost ! I just wanted to give a short working guide without all the thrills .... your technical advise is great but most newbies won't know what in the world you're saying . If they got it from a manufacturer they can call their support there and give the system makeup first. As I have seen many times over here they rush out and buy bucu gigs or the wrong thing and are screwed. It's a simple "first do " that they don't have to search posts and ask gurus with over technical answers to find out first . These facts are complete basic do's . Why make it hard .... and why pay some idiot $20.00 - $40.00 to pop in 2 sticks of ram at a store ? If nothing else dig out the MB book that came with the system or the one that they got when they built it . MONDOMAN ... Yep -yep - yep ! I forgot to add the dual channel dual stick specs -----

 

[Mondoman]

t - I'm hoping your post above was only partly directed at me (the 2nd part).
Part 10 I'm hoping is pretty much what you're talking about wrt a short list of what to buy -- there seem to be a lot of questions about if slower RAM can be used on a faster MB or vice versa, and unbuffered vs other RAM. I'm not sure how to make that much simpler.

PS - check out changes to point 5.

 

[trooper1947]

NO .... what you put was very good . I was talking about the ones who just confuse some who know nothing about system build but need very basic info to just do the simple things . You took basics to the next step if they wanted it . Like one guy on another forum who bought a new powerful video adapter and did'nt plug in all the power ! He was wondering why it crashed ... thought 1 would be enough . Like you wrote some can be "memory" different but will work but believe me the folks I assist here do not and will never understand the technical issues . I and probably you have been here before and since 088 's with green text monitors and 3.1 windows on floppies . I remember arguing with my sons and wife that windows was the wave of the future and they hated it and said DOS will never go down and windows will be dead in a year !! LOL

 

[fpdoc]

Thanks for the post trooper.
I had to do a lot of catch up reading to figure out all the changes occurring and looking at compatibility. I have an AM2 590 board, and the manufacturer's website has a list of compatibile memory- that's always a good place to look. As far as memory speed goes, I went with the DD2 800 for future proofing or if i changed platforms to a more overclockable CPU.
As far as learning goes, Im hooked on these forums because people like you and mondoman bring a lot of knowledge. We all start knowing little and learn as we go. I guess it depends on how big the mistakes we make and how we expose ourselves that leads some to belittle others on these faults.

 

[trooper1947]

FPDOC .... and we can help those folks without calling them foul and ignorant names as do some on the forums . Seems when someone makes a mistake these " I KNOW IT ALL " punks ... who should be called that .... use low blow name calling and tell them how stupid they are . Hey I'm learning something new everyday about systems as anyone will have to with the advancement in technology . Tom's Hardware has been a God send .... they get the items ... test them brutally and give an honest report ! I surely can't get all that hardware and run it ... this site has been a fabulous help since I found it day one ! I have sent hundreds here over the years to compare before buying . I'll install and setup their hardware but it's their choice as to what they want ... need .... or can afford . It's really a pleasure to communicate with someone like you on here . I have set some down in front of my computer to go here who did'nt have internet or high speed to read the specs and tests here . Hey I've screwed up and used wrong descriptions on hookups ... like calling dual sli ... crossfire .... and you would'nt believe what a couple forum participants wrote ! Horrible names !