well just to throw a spanner in that theory, the reason I've got this 256MB chip is I bought it for someone's packard bell who had EXACTLY the same type of RAM (different manufacturer) but when both chips were in, the upper chip was getting memory errors (swapping them round only 256MB was detected). The chip was detected but windows kept crashing and a special memtest app revealed problems. I got them a matched pair and it worked fine, and the previously "duff" chip was able to be run as a 3rd one giving 768Mb RAM without errors, except I kept it in the end. Weird hunh?
Also I'm running my P4 3.2GHz with a matched pair and some special mode is set in the bios to make use of it, can't remember what it's called.
Also I'm running my P4 3.2GHz with a matched pair and some special mode is set in the bios to make use of it, can't remember what it's called.