HP Pavilion dv7 notebook
Intel i5 M450
ATI m5650/Intel HD integrated chip
Win 7 Home Premium 64bit SP1

My HP notebook, which I bought last summer, came installed with 4GB RAM, and has not been modified since. On the Control Panel System page under "Installed memory (RAM):" it said "4.00 GB (3.5 GB usable)", and I understood that the other .5 GB was how much Windows or other necessary background services were using. This was fine, and I had no problems with the notebook, but sometime around the last week of May, that line in the CP changed to "4.00 GB (2.43 GB usable)," and the sudden drop in usable RAM has severely affected performance. Literally overnight, my fps in games dropped from 40-60 at max settings, to 10-20 at min settings, and 0-5 fps whenever the graphics changed quickly. It took me awhile after that to finally realize I'd lost over 1 GB of RAM, but I'm at a loss as to what WOULD have dropped my usable memory by that much.

The HP Pavilion series do have the 'SWITCHABLE graphics' feature, with both a dedicated card and an integrated graphics chip, and usually some amount of RAM is dedicated to the integrated chip...however, I would have figured the amount needed for integrated graphics would be very small, and part of the .5 GB that was UNUSABLE up till last month. I'd been using both graphics options for about 8 months with 3.5 GB available (HP doesn't release new DRIVERS for switchable graphics sets, so it can't have been a graphics related update), so it doesn't seem like this feature was the culprit.

Until I get other advice, I don't have much of a guess if this is a hardware or software problem, but I thought and have been told the CP recognizing the drop in usable RAM usually indicates Win 7's memory USAGE, so I figured I'd post it here.

If anyone has any ideas or questions that might help me figure out what suddenly happened to another 27% of my RAM, please post!

ThanksAre you talking about a particular game on sudden change in performance? I would check first on your hardware temps. since you mention its a laptop for gaming...? Performance dropped on any/every game or program that uses a substantial amount of RAM (MMOs, FPS shooters, Photoshop, etc). Since I had to switch things to min settings, temps have actually fallen nearly 10° C (~75° average while gaming), but that made no difference in performance, and temps were always fine before.

While testing the problem out in a few games, I could still set settings back on high, and have high fps if I was just standing still...but if I turned around quickly, or something else came across my screen quickly, (increasing load on memory resources) my fps would drop below 10, so it seemed to be related to the sudden drop in usable memory while running Windows.You could have unwanted background processes running but yet we can't be sure here. Just a suspect. How about your CPU usage? Make sure to set your default resolutions first. A sudden drop in RAM usage would be when turning off other activities such as browsing or any applications.