Saved Bookmarks
| 1. |
Solve : I installed 4GB Ram but its only showing 3GB Ram - Please Help Me? |
|
Answer» I installed 4GB Ram but its only showing 3GB Ram 2.55MHz Dual Core Proccessor it's 2.55 ghz if there was such a thing as a 2.55 mhz it would take forever to download windows A commonly overlooked item with respect to your problem is checking to see whether the M$ Configuration Utility is limiting the use of ram in your system... click start, RUN, type msconfig, click "ok" click on the boot.ini tab, click on Advanced Options, and make sure the /MAXMEN= box is UNCHECKED... If it is checked, then uncheck it, click "apply", "OK" and restart....then see if all your memory is showing up Answer: Windows XP really supports 4GB Max but it shows 3GB because one is reserved for the system. I have Windows Vista Home Premium 32 bit (hate this version of vista) with 4GB of RAM and it shows 4GB maybe of service packs. Install XP SP3.There is no SP3 for the 64 bit version, only SP2If you can get 3GB with the 32 bit OS, be happy This is discussed in great detail on the MS Support site. Some users never go beyond 3GB because it is such a hassle to get 3GB + to work. Do not expect MS to do any more work on the XP system. Here is a link to the MS site for XP: http://support.microsoft.com/ph/1173It's not really a limitation of the OS but rather of the architecture, I believe. 32-bit addressing and whatnot- 2^32 = 4,294,967,296 bytes, or 4GB. In fact, a very similar issue is what caused the original 640K barrier; the address range of the 8088/8086 could only address 1MB of RAM- so when you had all that installed, you couldn't see all if it. (although this was partly built into the OS to reserve said space). Quote It's not really a limitation of the OS but rather of the architecture, I believe.Please let me help you. Go to Memory Management 101 http://blogs.technet.com/askperf/archive/2007/02/23/memory-management-101.aspx And don't say you already know that. There will be a pop Quiz by the end of the week. I already DID know that. ever wonder WHY they built it with 2GB User space and 2GB kernel space? Weird how it adds up to exactly 4GB for each process, no? It's almost as if... wait... OMG! it might be somehow related to the aforementioned fact that it's a 32-BIT CPU. IE: 2^32=2GB, which I explained already. of course you graze right over that and assume that because the OS only supports up to the architecture limit that it's a OS limitation, not a limitation of the architecture. a 32-Bit CPU simply cannot address over 4GB of RAM- without the explicit usage of hardware and software hacks like 36-bit PAE, which requires support across the board. However- these are just that- hacks- they basically work-around the issue, that the CPU is 32-bits. (And of course, any 32-bit OS running on a 64-bit CPU will be running through an emulation LAYER (at the CPU level) whereby the CPU acts like a 32-bit CPU anyway). In order to access of this RAM- you need Hardware(CPU) and software (OS.. or more specifically, OS API's such as Address Windowing Extension)) support for PAE. And- more importantly- programs that are FLAGGED as "large address aware". (linker flag). To reiterate: in order to access 4GB of RAM you need 32-bits of Address bus (assuming that individual bytes are addressable (as opposed to something like what is done with hard disks, which are accessed in clusters). This gives us a dilemma- the same one that IBM faced with the Original IBM PC (why do I suddenly feel like I'm repeating myself...) And that dilemma comes about because your going to want.... no, your going to need more then just memory in a computer - you need things like graphics cards and hard disks and electronic yogurt makers to be accessible to the computer in order for it to be able to use them. So, just as the original PC had to carve up the 8086's 1MB addressing range into usable memory (640K) and 'reserved' (384K), so too must the addressable memory of a 32-bit address range be carved up for system components. For a long time this wasn't a problem, because there was a whole 4GB of address space, so devices typically lurk up in the upper echelons of RAM (upper 1GB, usually) leaving the bottom 3GB for memory. So of course- what happens when we install 4GB of RAM in a 32-bit environment is we're thrown back to the days of old (again, a feeling of deja vu sweeps over me, as I remember my far more terse post from before ); there's a whole in the memory map for I/O (now it's only 25% of the total address space but it's still a big hole) So the lower 3GB of your RAM will be available, but there's an issue with that last GB. To AGAIN reiterate- this is NOT a windows problem- or even a problem with any 32-bit OS- it's a x86 hardware issue (you know, a limitation of the architecture, which I believe somebody already said... who was it... hmmm.... oh yes, it was me!). the memory hole is quite literally not even visible to the CPU, no matter what 32-bit OS you choose. of course- the only solution? use a 64-bit CPU and a 64-Bit OS. problem solved- since a 64-bit CPU can address 2^64 bytes- or 2 exabytes of RAM. (remember, giga, tera, peta exa....) |
|