|OK, I looked at your original Topic thread. |
"Post the exact brand and model of your computer or motherboard if custom built."
Most mboards automatically disable onboard video when a PCI-E card is installed in a slot, but some DO NOT, especially some more recent ones.
E.g. I recently installed an Asus M3A78 Pro mboard - by default it does NOT auto disable the onboard video when you install a PCI-E video card in a X16 slot, and the card produces no video. You have to change settings in the bios. If you install certain specific ATI chipset cards in the PCI-E slot and use Vista, you can set it to Hybrid mode in the bios and have both the onboard video and the card in the slot work, and in that case the onboard video still shares part of the installed ram.
You may just not have noticed previously the onboard video was still enabled.
512mb - 448mb = 64mb.
64mb was probably being used by your onboard video.
Some bioses report the amount of ram MINUS that shared with the onboard video. Some also subtract 1mb for the conventional memory amount - the ram used by the operating system that can't be accessed by the user or used for changable operating system data by the operating system.
If the onboard video has been auto disabled, in almost all cases the bios then ignores settings in the bios regarding sharing ram with the onboard video, the total ram installed is reported by the bios, and any setting regarding setting Intialize Video first or Primary Video or similar in the bios is also ignored by the bios when iset to onboard video, if it can be set to onboard video or similar.
Not all ram that you would think should work in it is compatible with your mboard.
Tell us what the brand and ID strings (part number characters) that are on the ram modules you've tried.
Other than ram compabilty problems, you can experience really odd problems sometimes if the modules are not getting a good connection in their slots.
A common thing that can happen with ram, even ram that worked fine previously, is the ram has, or has developed, a poor connection in it's slot(s).
This usually happens a long time after the ram was installed, but it can happen with new ram, or after moving the computer case from one place to another, and I've had even new modules that needed to have their contacts cleaned.
See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
Usually ram slots are not the problem, unless they have physical crap in them or on their contacts. You could try using a few drops of isopropyl or methyl alcohol on a tissue or coth wrapped over thin cardboard in the slots, but that's usually not necessary.
I have never encountered any ram slot that was actually BAD, unless someone had installed ram backwards in the slot and then tried to boot the computer, in which case the module fries and the slot's trashed forever.
However, ATX power supplies are always powering ATX mboards in some places including some contacts in the ram slots even when the computer is not running, as long as the PS is connected to the mboard, the PS is on, and the PS is receiving live AC power. If you did NOT disconnect the AC power to PS, at any time, while connecting or disconnecting anything connected to the PS or the mboard, you can easily damage mboard components and circuits, including the ram and circuits for the ram slots.
" Okay. I then put stick A into slot A and stick B into slot B and instead of 1,024MB like I should have or even 896MB like you think it would tell me under the circumstances, it tells me I have 504MB. I then take stick A and put it into slot B and stick B into slot A and fire it up and it tells me the same thing, 504MB of RAM."
If you were still using the onboard video and it was set to share 64mb of ram, if both 512mb modules were recognized properly, the total reported by your bios would have been 448 plus 512 = 960 mb.
The fact that you're seeing 504 when both are installed, whether or not if the onboard video was using 64mb, indicates either
- your mboard circuits are damaged, probably the ram slot circuits - extremely unlikely
- your ram is damaged despite the fact it appears it's recognized fine when installed by itself - possible but unlikely
- OR - one or both ram modules are incompatible with your mboard - many times more likely. Sometimes incompatible modules are recognized correctly when installed by themselves, but are not recognized properly when more than one is installed.
Once I/we know your mboard model and ram ID strings, I /we can probably find out if that is likely your case - if it isn't, THEN I suspect your mboard circuits are damaged, or the ram is damaged.
You could install the ram modules in another mboard they are compatible with for sure to see if they're recognized properly. That's not valid unless the modules you install are in a list of modules found when you search using the model of the mboard.
If they're brand name system modules they often have an oddball brand name specific ID string. If they don't also have the actual maker's standard IDstring, some other modules with standard IDstrings will work, but they are not listed.
Another - remote - possibility, but I've never heard of it happening. On some more recent mboards the memory controller is built into the cpu, not the mboard. E.g. AM2, AM2+ mboards/cpus.
In theory it could be one or more pins on the cpu are not connecting to the cpu socket properly
In that case you could try re-seating the cpu in it's socket, but you'll probably have to remove the cpu heatsink before you can get at the socket lever. Check the cpu for bent pins while you're at it.
OR - the memory controller on the cpu could be faulty, but I've never heard of that happening.