To RAM or not to RAM? That is the question?

Short version: I have 4 RAM slots. By a story, I have two sticks of 1 Gig RAM, and two sticks of 500 MB RAM.

Being computer illiterate myself, I've received conflicting advice:

1) Put all four sticks in. The more RAM the better!

2) Put only the 1 Gig sticks in. Putting in smaller bits of RAM triggers an effect that ends up slowing down the computer, rather than helping it.

Both came from people that are absolute computer experts, so I'm very confused.

Ergo... to RAM or not to RAM?

Hmm... I haven't ever come across someone saying that 2 gigs is going to go faster than 3 gigs. I think it may be possible that 2 500mb sticks is slower than a single 1 Gb stick, but the other one just sounds implausible. I'm not much of a hardware guy, though.

Put it all in.

As long as all the RAM meets the specs for the board, put it all in. Any speed differences that may exist from mismatching pairs like that (which is not likely an issue anyway) would more than be made up for with the help of the additional RAM.

Edit to expand on the speed issue: It's true that some (though not all) chipsets will slow the memory access speed to the slowest module, however the speed has nothing to do with the capacity. While one set is half the capacity of the other, the speeds are more likely very close - more like speeds of, say, 10 versus 12, not 10 versus 20 (to toss out some random numbers). You're much better off adding the extra memory than worrying about any slight difference in speed between them, as long as they all meet the specs needed for the system.

I upgraded my parent's system (2.4GHz P4) from 512MB to 1.5MB. Kept the smaller pair where they were and installed the larger pair in the empty sockets.

As long as both pairs of memory can be configured to run at the same speed and timings, there really isn't a problem.

Now there I've seen motherboards that advertise extreme memory speeds but only for one pair (or triplet) of memory, the second pair prevents such aggressive speeds.

There is also Command Rate, one of the more obscure timing values. I usually see this talked about more with AMD processors and motherboards where one pair can be set for a Command Rate of 1 but two pairs can't. Here is an old article (DDR days) that benchmark the differences between Command Rate and timings. Needless to say but in games with their setting cranked up, the video card is your limiting factor, not memory timings.

The thing is, more real memory is always better if the system ever needs to start hitting the swap file hard. Doesn't matter how much performance you may lose because of single channel Vs dual or more conservative timings or slower memory speeds, needing the swap file is a million times worse.

My parent's machine for instance needed to hit the swap file while booting up and logging in, due to the anti-virus, anti-malware, HP printer/scanner drivers, GPS utility, etc loading. Once loaded a good chunk of memory was freed up but during the load process over 600MB was committed on a 512MB system. With 1.5GB now, no slow down on boot plus more memory usable for drive caching.

Put it all in. Even if it does go down to the lowest speed ram of the set its not going to matter much the speed hit isnt even going to be detectable by a human anyways. You are looking doing some crazy benchmarking just to even notice the difference.

Put it all in. I'm going to guess the speed of your sticks is either 667MHz or 800MHz based on the size; if you install it properly in a Dual Channel motherboard, the speed difference will be 1334MHz vs. 1600MHz.

If you want to know your current memory timings, download CPUZ from http://www.cpuid.com/cpuz.php and look at the Memory and SPD tabs.

In the Memory tab, look at Channels #: "Dual" means it's operating under dual channel (reading/writing from 2 sticks at once) and DRAM Frequency displays the actual frequency the memory is operating at. Example, in my system: DRAM Frequency 480MHz (due to a little overclocking), x2 because it's DDR2 memory = 960MHz; x2 because it's Dual Channel = 1920MHz final speed.

In the "SPD" tab you'll be able to select each slot of memory in your motherboard and see what speeds each stick supports; it'll be a table at the bottom. Again, because it's DDR2 memory, you have to double all the values you see.

Neat thread and a question kind of related. I have 9GB in my rig. Is there a point in going above that?

You want to keep each stick of ram at the same capacity and the same speed or It will cause conflicts... unless something was changed in vista and 7. 4 1 gb ddr3 pc10666 for example are fine but you wouldnt want to mix anything. Some will even say not to mix different manufacturers of ram which is more than likely a bad thing too.