3.5 gigs of ram instead of 4?

[ktimekiller]

windows detect 3.5 gigs instead of 4, i heard that it was limits of the xp, is this true?

 

[Pi Mu Rho]

It's a 32-bit thang. If you want more than 3.2Gb, you need to go 64-bit.

 

[Kyorisu]

You should be aware that to make full use of 4GB of system ram, a 64bit operating system and motherboard support of "memory hole remapping" is required.

 

[ktimekiller]

so im stuck with 3.5 right?

Even if I am, thats ok, it was a 2 1gig stick package for 30 bucks from new egg.

Having half of a stick performing wont interfere with performance will it?

 

[DEATH eVADER]

Even though 32bit architecture should technically use 4gigabytes. Even so a 64bit architecture can support much more (equivalent of 2^64), so if you did upgrade to windows 64, you should be able to use that extra 512mb.

You would only be bottlenecked by the limit the motherboard can take

 

[Kyorisu]

Even though 32bit architecture should technically use 4gigabytes.

...

http://users.on.net/~matthewd/valhalla/4gbram32bits/32bitxpvs4gb1000pix.jpg

You can see from the basic no video option that in these systems the memory hole is consuming 286MB of system ram, thus all VGA memory address allocations must occur beneath this 3.81GB barrier. Interestingly the 128MB Radeon card is actualy taking 190MB of address space, and the 256MB 8500GT is also consuming more address space than its memory size (310MB). Both of these cards are consuming approximately 60MB of address space in excess of their actual frambuffer size.

Once we get into the larger cards, the opposite becomes true. A 512MB card only consumes as much address space as a 256 (310MB). The 768MB card (as well as the 512 AND 256 inserted together) consumes 560MB. The 1024MB card reduces overall system ram by utilising 810MB, and our "virtual" larger cards of 1280MB and 1536MB both consume 1310MB. This finding directly supports the suggestion that not all of the VGA ram is directly mapped to 32bit address space.

Thus it would appear that each range of memory size has an associated and fixed penalty. We hypothesise that the 320MB 8800GTS (v1) will fall into the 310MB category and the 640MB version into the 560MB range, but are currently unable to test this as the AdRENALiN product manager does not keep demonstration examples of EOL'ed products. Based on these discrete ranges of memory consumption, it would seem prudent to select the largest possible VGA buffer size within an acceptable system ram reduction penalty, and in some cases its obvious that additional ram above the 2GB point becomes wasted unless a 64bit operating system is used.