macman2790 said:They only use 3.2, dell should be brought to justice for selling 4gb of ram in their notebooks.
Actually, they disclose this information in the fine print (although a potential buyer has to dig for the proper info to sort it all out). Several PC manufacturers are doing this for a couple reasons. One is performance, if someone wants more than 2G of RAM, they must either install 3GB or 4GB. Even though the system can't address a full 4GB of RAM due to the 32bit limit, they still put it in so the RAM modules are matched spec and the user can still benefit from the dual-channel capabilities. Some vendors, like Apple, are only offering mismatched 3GB configurations in their Merom systems. This way, they're not selling you any RAM you can't use, but the end user is also losing out on the extra bit of performance from dual-channel mode. So, you pick the lesser of 2 evils...
Personally, where I think Dell is wrong offering 4GB in their fully configured XPS 17" notebooks is that they're also selling it with a 512MB 7900GTX video option. By the time you account for 4GB max address space with the 32bit chipset, subtract the 512MB for the video memory plus the other memory addresses for every other piece of hardware in the system. You actually come up with about 2.8GB usable. So they're charging users (many of them unknowingly) an $800 premium for 4GB of RAM, but in reality they can only use about 800K of it over the 2GB option and they don't gain any performance.
I think many users and vendors are hoping for some kind of magic BIOS upgrade that will patch or work around this chipset feature and let them use all their RAM. ...Won't happen. I suppose it's possible, but working RAM paging through BIOS would be too slow to be worthwhile and probably not all that reliable.
Depending on the timing of Apple's next update, I may or may not jump the gun and buy a Macbook for the wife. But I'm keeping my current MBP until we have 4GB or more of usable RAM addressability, an updated GPU and possibly will even wait for the 800MHz FSB if Apple doesn't release this year.