I was just thinking about upgrading my RAM from 512MB to 2GB, so I started searching the internet for some info. The info I got put me in one heck of a CONFUSION! FSB, DRAM Frequency, Memory Speed, Clock speed, Bus Speed, SPD blablabla - what do all these mean and what factors to keep in mind when upgrading RAM? Is it better to get 512MB(DDR-400) or 1G(DDR-333)? I did read some threads on this forum but didn't really understand much. Here's my system info: Motherboard: D865GSA Maximum Memory Capacity: 4096MB* Currently Installed Memory: 512MB Available Memory Slots: 3* Total Memory Slots: 4* Dual Channel Support: Yes CPU Manufacturer: GenuineIntel CPU Family: Intel(R) Pentium(R) 4 CPU 3.06GHz Model 4, Stepping 9 CPU Speed: 3057 MHz I got the above information by scanning my system at crucial.com *The scan shows 4096, but it can't be more than 2048. *shows 3 available memory slots, but I see only one available on my motherboard. *shows 4 memory slots in total whereas there are 2 on the board. Why did the scan result in wrong info? CPU Got this info using 'Advanced System Information Tool' L2 Cache: 1MB System Bus Clock: 531.8MHz FSB Clock: 133MHz QDR Multiplier: 23.0 From BIOS System Bus Speed: 533MHz System Memory Speed: 333MHz In BIOS there's also an option of DRAM Frequency which is set to Auto.

According to what I read about the mobo, it will handle up to 2 gigs of ddr pc3200 ddr400 memory. I fyou want to max out the machine, go to a place like newegg.com and look for a pair of mem modules that are the above specs. Your mobo doesn't support dual channel memory, but you can still use the modules. Look for pc3200 ddr400 unbuffered non ecc chips.

You wrote "Your mobo doesn't support dual channel memory" I think it does. Motherboard: D865GSA Maximum Memory Capacity: 4096MB* Currently Installed Memory: 512MB Available Memory Slots: 3* Total Memory Slots: 4* Dual Channel Support: Yes CPU Manufacturer: GenuineIntel CPU Family: Intel(R) Pentium(R) 4 CPU 3.06GHz Model 4, Stepping 9 CPU Speed: 3057 MHz In BIOS there's an option of DRAM Frequency which is set to Auto. Should I leave it to Auto or set it manually? And could you please tell me the difference among: System Bus Clock, FSB Clock, System Bus Speed? And what's the difference between System Memory Speed and DRAM Frequency? And does a motherboard also have bus speed?

This may make things even more confusing, but it usually makes things easier to speak in terms of frequency. Bus speeds are theoretical/advertised speeds, frequencies are actual speeds. You also need to know a little CPU history & theory. Intel "quad-pumps" the FSB so to determine the actual frequency, just divide by 4. For instance, your P4 runs at 533MHz FSB, so the frequency is 533/4 = 133MHz. All DDR Ram is "double-pumped" so to determine it's frequency, divide by 2. DDR333 has an advertised speed of 333MHz, so the frequency is 333/2 = 166MHz. The vast majority of systems perform best with the CPU & RAM running at the same frequency...this is known as 1:1 ratio. However, the P4 is a highly inefficient CPU & it was determined a long time ago that it performs best with the RAM frequency faster than the CPU frequency. The two best ratios are either 3:4 or 4:5, depending on the CPU's default frequency. 400MHz & 800MHz FSB P4's should be run at 3:4, 533MHz FSB P4's should be run at 4:5. What this all means is the best RAM to pair up with your 533MHz FSB P4 would be DDR333. BTW, have you opened your case & examined the board? Acoording to Crucial AND Intel, it only have 2 memory slots & supports a max or 2GB, 1GB per slot. Where did you get your info from? http://www.intel.com/products/mothe... http://www.crucial.com/store/listpa...

"What this all means is the best RAM to pair up with your 533MHz FSB P4 would be DDR333." I've got two 1G DDR-400 modules, now is this going to have any negative effect on the performance since it violates the best ratio(3:4 or 4:5) theory? Is there some tweaking I can do to make the best use of my DDR-400 modules? "BTW, have you opened your case & examined the board? Acoording to Crucial AND Intel, it only have 2 memory slots & supports a max or 2GB, 1GB per slot. Where did you get your info from?" Yes I have; there are only two memory slots and that's exactly what I mentioned in my post above. Scan at Crucial showed 4 slots, which I failed to understand.

I'd really appreciate some help!

Just put in the DDR-400 modules and if it boots up and everything works it'll be good..... :-) I think most people will not notice the little speed difference except hardcore gamers. But if you really want to downclock the memory try asking in the CPUs/Overclocking forum. Maybe your motherboard bios has settings you can tweek...