Want to get the maximum amount of ram for my laptop 3gb. But it only possible to get 2*1gb or 2*2gb no single 1gb sticks or 2gb stick. Is it ok to stick 4gb in there? laptop is a acer aspire 7520
How much is the supported maximum of the laptop? It's ok with 4GB, if the laptop supports it. Also, if you don't have a 64-bit operating system, it will report only like if ~3GB would be installed.
No. If the max memory supported is 3gb... which is a weird number to max out at, then don't put more in. I think it would only recognize one stick in that situation. I'm finding plenty of single sticks of 2gb and 1gb ram on Newegg. I'm not sure where you're buying from but maybe look somewhere else or just get the 2*1Gb sticks. 2GB isn't 3GB I know.. but it sounds like it'd be a lot more convenient, plus they'd be a matched pair.
I would probably say that Acer are playing it safe in their specs and stating 3gb as the max because the pre-installed 32bit windows will only use about 3.5gb or so of the 2*2gb sticks. I cant think of any hardware issue that would make the mobo support 3gb and not 4. Indeed most manufacturers recommend a matched pair of sticks, so either 2 or 4gb would seem the natural configs. Given that memory is so cheap these days, putting 4gb in and getting 3.5 aint so bad.
Get two of these 2GB A-Data Vitesta (667MHz) modules - around £50 delivered I bought a pair of those same ones when they being offered for £18.69 + VAT each, and just 99p delivery (from their 'Lucky Dip' newsletter)
The sections on avoiding 32-bit are maybe out-of-date with Vista, but the final paragraph may explain the Acer reasoning. Intel boards will handle 3 modules (ie, asynchronous RAM) better than most AMD. IIRC one of the recommendations from Crucial for my board was 3 x 1GB.
