what are the numbrrs on ddr ram?

[mystvearn]

What are the numbers that say pc1600,pc2100.Is the bigger the number, the faster? W
What happens, if I place ea RAM that has higer numbers in a motherboard that does not support it?
I did it with pc133 that is compatible with my pc100 asus motherboard.

[Spyda]

thats not DDR rAM, thats SDRAM, DDR RAM requires a different shaped slot on the motherboard

[mike breck]

FSB Speed DDR Ram speed Name(s)
100 Mhz 200 Mhz PC-1600 or DDR-200
133 Mhz 266 Mhz PC-2100 or DDR-266
150 Mhz 300 Mhz PC-2400 or DDR-300
166 Mhz 333 Mhz PC-2700 or DDR-333
200 Mhz 400 Mhz PC-3200 or DDR-400

In theory, DDR is supposed to be backward compatible.

All being well, if you place PC2700 in a mobo that only supports PC2100, then the PC2700 should work - allbeit at PC2100 level.

What is more questionable is if you try to use PC3200 in an older DDR mobo. It will depend on the mobo and the brand of Ram.

Another problem is whether the Ram is "compliant" to official JEDEC (Joint Electron Device Engineering Council) standards or just "compatible" with JEDEC standards.

At lot of Ram manufacturers brought out PC-2700 before the standard was officially approved by JEDEC. So this Ram was "compatible" with the proposed PC-2700. Other manufacturers like Crucial hung back until the standard was officially approved by JEDEC, so therefore their Ram is PC-2700 "compliant".

What does that mean in practical terms? Well as JEDEC "compliant" Ram meets the "official" industry standard, then it should be more compatible with many mobos than pre-released, so called "compatible" Ram.


Does that make sense?


HTH

[mystvearn]

Thanks. Now which motherboard has the fastest Ram and supports agp8x? I've seen asus p4g8x deluxe,but has pc2100/pc1600

[sleepypost]

The newer boards almost always support DDR-PC 2700 or higher now. My A-Bit KD-7 Kt-400 supports PC 2700 and yes in deed I am using PC 3200 DDR ram in it. It's funny because I spent 100 dollars more for nothing! Oh, wait, I should have just bought PC2700, crap! Learn from my mistake.

[Furius92]

For an Intel CPU, I think your best bet would be an Asus P4PE. However, it does not support AGP 8x. But that shouldn't even be considered an issue. Benchmarks and testing show that using the same system, AGP 8x provides little to no improvement (1-2%) over AGP 4x.

Now, although you want the fastest memory, there is something else involved. While the P4PE supports memory that operates at high clock speeds, the P4G8X supports dual-channel DDR. So, in effect, you are running PC4200 in the form of two channels of PC2100. Of course, you don't get exactly double the amount of bandwidth but the difference is enough to put the memory bandwidth of a P4G8X above that of an P4PE, or better yet, the memory bandwidth Intel 7205 (Granite Bay) Chipset above that of Intel 84PE chipset. Remember though, you need to use 2 or 4 DIMMs in the P4G8X, while you can use 1, 2 or 3 in the P4PE. And the 2 or 4 in the P4G8X must be the same size (e.g. both are 128MB, or all four are 128MB).

[mystvearn]

I know the board supports 8x(p4g8x) and 2 rams of the same kind. Do I also need the rest two rams the same as well? What is the significance of making all the same RAMs? Does DDR operate different than SDram where I can mix all kinds of mb of ram? The reason I'm looking towards this board-is that it supports 8x-which will eventually kill the 4x. I have had a hard time during my last upgrade of 3dcard on my previous motherboard-ASUS CUBX4400X where the board only supports up to 2x. ANd finding Geforce2 or higher is a problem. I found one card from AOPEN-geforce 2 ti 6mbd ddr. Its ok. Are there other alternative boards with 8x? or is there a board that has the max support for DDR-not SD-so that I can upgraqde it whenever necessary.