If the OS and the hardware can actually handle (practiaclly speaking) unlimited ram, is there a point that adding ram would actually slow down the system assuming you use the ram for what ram is usually used for and not make large ramdrives or just let a large amount go unused?
On a standard PC running Windows 2000 or XP, that limit is 4GB. Up to 64GB is supported, but the OS must make use of a hack called the 36-bit addressing extension which REALLY kills performance. Once we move to 64bit processors, we won’t see another RAM limit for about 30 years.
Windows 95/98/ME only support up to 512MB. Exceeding 512MB will result in constant “out of memory” errors.
Yep, and there can be hardware issues as well that make it not worth while to have too much RAM. In particular, some mother boards can’t cache above some limit, so when you put in more RAM, performance drops incredibly. The ones I know of have limits at 512MB and 1GB.
Urrk. First read, then post.
There is a relationship between addressing space and program size/execution speed. That relationship is the size of the address. To address a specific byte in a 64 bit address space, you have to specify a 64bit address. This takes more space in the program code, and requires more data to be read from memory - you need 64 bits times 8 to read a 64 bit address that is stored in memory if you read by bytes. You can use a larger read (Word - 16 bit, double word 32 bit, don’t know what you call 64 bit reads) so that you only have to specify the address once or twice.
If your processor (and OS) are 32 bit, then addressing 64 bits of address space gets hairy - and slow. If you have a 64 bit OS and processor, then things are faster, but the programs are larger by necessity.
Adding RAM past the native addressing range of the processor and/or OS will slow you down - drastically.
Mort Furd: Since the release of the Pentium II on Intel platforms and the Athlon on AMD platforms, caching has been done by the CPU, eliminating the motherboard as a performance factor. Since 64-bit consumer CPUs and a 64-bit version if Windows XP will be out by the beginning of 2004, we won’t really have to worry about the 4GB memory limit in consumer systems.
WAG: Triple word? 
Vaxen (computers from the 70’s, just in case you think this is new) called them:
8 bits: byte
16 bits: word
32 bits: doubleword
64 bits: quadword
128 bits: octoword
i read an article about this in a pc mag…basically the article was comparing an amd system with an intel system, they gave the intel faster ram than the amd, someone then wrote in saying umm wait a second, wouldn’t results be better for amd if it was given the same ram as the intel?..they then went on to say that if you give a processor faster ram than it can support through its fsb it will actually slow down
okay now that i think about it your post was more concerning amount of ram not speed, but i guess this i’ll still put this out cuz it is kinda interesting
The board instruction manual always states how much memory you can put in.
idol mind: Memory can always underclock to match the FSB. It is possible on some chipsets to set RAM to run faster than the FSB, and yes, this causes performance loss. However, when setup properly, you’ll see no difference between DDR400 and DDR266 when the FSB is at 266Mhz DDR.