QUESTION #1
What is the difference between:
256MB PCI-Express x16 NVIDIA GeForce 7800 GTX
256MB PCI-Express x16 NVIDIA GeForce 7800 GT

Besides the fact that one has an X on the end and costs twice as much?

QUESTION #2
What is the difference between types of RAM?
What is timing? i.e. 5-4-4-9 (are lower numbers better?)
PC2-8000 vs. PC2-5400 ?

Corsair XMS2 Dual Channel 1GB (2 x 512MB) DDR2 PC2-8000 5-4-4-9
Corsair XMS2 Dual Channel 1GB (2 x 512MB) DDR2 675 PC2-5400 3-2-2-8
Corsair XMS2 Dual Channel 1GB (2 x 512MB) DDR2 675 PC2-5400 4-4-4-12

QUESTION #1
What is the difference between:
256MB PCI-Express x16 NVIDIA GeForce 7800 GTX
256MB PCI-Express x16 NVIDIA GeForce 7800 GT

Besides the fact that one has an X on the end and costs twice as much?

As far as I can tell, the GTX's appear to have higher GPU clock speeds and faster memory, therefore a little more performance.

QUESTION #2
What is the difference between types of RAM?
What is timing? i.e. 5-4-4-9 (are lower numbers better?)
PC2-8000 vs. PC2-5400 ?

Corsair XMS2 Dual Channel 1GB (2 x 512MB) DDR2 PC2-8000 5-4-4-9
Corsair XMS2 Dual Channel 1GB (2 x 512MB) DDR2 675 PC2-5400 3-2-2-8
Corsair XMS2 Dual Channel 1GB (2 x 512MB) DDR2 675 PC2-5400 4-4-4-12
Timing is everything. To break it down Barney style, the lower the timings, the less clock cycles it takes for your memory to respond to a command from your computer to read, write, clear, set, reset, etc... Depending on the system, it's entirely possible to get a computer with PC3200 and 2-2-3-5 timings to outperform a computer with PC2-5400 and 4-4-4-12 timings. You have to have a combination of a quality northbridge chip, quality RAM, and quality CPU. This is another reason I go with AMD. While Intel machines support faster DDR2 memory, the faster memory tends to have slow timing to compensate for what the silicon is capable of. PC3200 or 3500 can easily be had with a latency of 2. One example is this:
http://www.newegg.com/Product/Product.asp?Item=N82E16820227052
The timings on this are 2-2-2-5. While the total bandwidth capability may not be as high, the memory responds relatively quickly, and can compete with higher speed DDR2 memory.

When selecting memory, first have a look at the motherboard you are using. Ensure that it will actually use the bandwidth that the memory can supply, otherwise it's kind of pointless to buy super high end PC2-8000 when your motherboard will only go up to PC2-5400 speeds.

Excellent info.

Follow up: What does the "Frequency" refer to... I see some have 333Mhz, some are 400Mhz, and some are..... 533Mhz I think...

Excellent info.

Follow up: What does the "Frequency" refer to... I see some have 333Mhz, some are 400Mhz, and some are..... 533Mhz I think...

Just the speed that the RAM runs at. Kind of like how fast the registers can switch from 1 to 0 and back. 333Mhz ram can do it 333,000,000 times per second and 533Mhz ram can do it 533,000,000 times per second. This is also directly related to how fast it can spew out 1's and 0's to the rest of your computer.

*head assplodes*

So which would be better:
a.) 1 Gig of 533Mhz Ram
b.) 2 Gig of 333Mhz Ram

I assume the 1 Gig of 533Mhz would be the fastest most of the time... however if you managed to fill up that Gig worth of space then it would be beneficial to have the 2 gig of 333Mhz.

For instance... if I'm just playing a graphics intensive game, such as Battlefield 2 or Fear, then the 1 Gig of 533Mhz will be the better choice. However if I am running Paintshop with 20 image loaded up, listening to Media Player, surfing the net, and chatting on trillian, then it would be better to have the 2 gig of 333mhz.

Is this a correct assumption?

Also do two chips work together.

So... if I have two 512Mb 533Mhz Cards it will work faster than one 1024Mb 533Mhz card?

*head assplodes*

So which would be better:
a.) 1 Gig of 533Mhz Ram
b.) 2 Gig of 333Mhz Ram

I assume the 1 Gig of 533Mhz would be the fastest most of the time... however if you managed to fill up that Gig worth of space then it would be beneficial to have the 2 gig of 333Mhz.

For instance... if I'm just playing a graphics intensive game, such as Battlefield 2 or Fear, then the 1 Gig of 533Mhz will be the better choice. However if I am running Paintshop with 20 image loaded up, listening to Media Player, surfing the net, and chatting on trillian, then it would be better to have the 2 gig of 333mhz.

Is this a correct assumption?

Sounds like you have a pretty good handle on the concept.


Also do two chips work together.

So... if I have two 512Mb 533Mhz Cards it will work faster than one 1024Mb 533Mhz card?
That get's into dual channel RAM. I'm not too familiar with the details on that honestly. I just know you can get more performance with 2x512 in dual channel than you can get out of a single gig stick.

dual channel vs. single channel is basicly a bandwidth issue.
it's sorta like a highway for your data.
If you run single channel the data travels thru "one lane" (or stick of ram) at a time where with dual-channel it can use both 'lanes' at once.

at least that is my understanding of it.
from what I have read the real-world performance increase is not going to blow your pants off or anything, but it comes standard on most motherboards now, and ram is cheap, so you might as well take advantage of it.

According to Sisofts "sandra" it is a good idea to use ECC ram with larger ram modules. something I did not do when I built my X2 box. :(