DDR RAM Question

[DJFuji]

Haven't kept up with the hardware industry lately (since the 1.2Ghz Athlon-Cs were all the rage), so i've kind of fallen behind on the whole DDR RAM thing. I understand how it works (rising and falling edge of the chip), but a few things confuse me.

a) Does AGP 8X and PCI run at a fixed rate? (i.e. 66mhz). If so, do they have adjustable multipliers so that you can run a high FSB and still keep PCI/AGP within spec?

b) DDR RAM of different speeds should not be used in the same machine, correct? I just can't see how a PC2100 and PC3200 would run together...

c) if you ran a 2.0Ghz chip at 200FSB (DDR 400) X 10 clock multiplier would that be any less stable (assuming you were using PC3200+ RAM) than a 133 MHz X 15 clock multiplier to get the same end result?

 

[Superman9534]

different speed DDR RAM can be used in the same system just as different speed SDRAM can be used in the same system. PC3200 DDR can be run at PC2100 speeds. They cant, however, run at DIFFERENT speeds, but the RAM itself is compatible as long as they are running at the same speed.

Most new boards have either a PCI/AGP Divider (1/4, 1/5, and 1/6 for 133, 166 and 200 FSB) OR a PCI/AGP LOCK which locks the PCI/AGP speed at a constant 33mhz/66mhz.

I dont think running a chip at 200x10 would be less stable then 133x15 as long as the chip is designed to go that high of FSB and you have 400MHZ DDR RAM. You would actually get a much better boost in performance.

 

[DJFuji]

Originally posted by: Superman9534
different speed DDR RAM can be used in the same system just as different speed SDRAM can be used in the same system. PC3200 DDR can be run at PC2100 speeds. They cant, however, run at DIFFERENT speeds, but the RAM itself is compatible as long as they are running at the same speed.

Most new boards have either a PCI/AGP Divider (1/4, 1/5, and 1/6 for 133, 166 and 200 FSB) OR a PCI/AGP LOCK which locks the PCI/AGP speed at a constant 33mhz/66mhz.

I dont think running a chip at 200x10 would be less stable then 133x15 as long as the chip is designed to go that high of FSB and you have 400MHZ DDR RAM. You would actually get a much better boost in performance.

Are athlon XPs spec'd to run DDR400 (200MHz FSB)?

 

[Corporate Thug]

Originally posted by: DJ Fuji

Originally posted by: Superman9534
different speed DDR RAM can be used in the same system just as different speed SDRAM can be used in the same system. PC3200 DDR can be run at PC2100 speeds. They cant, however, run at DIFFERENT speeds, but the RAM itself is compatible as long as they are running at the same speed.

Most new boards have either a PCI/AGP Divider (1/4, 1/5, and 1/6 for 133, 166 and 200 FSB) OR a PCI/AGP LOCK which locks the PCI/AGP speed at a constant 33mhz/66mhz.

I dont think running a chip at 200x10 would be less stable then 133x15 as long as the chip is designed to go that high of FSB and you have 400MHZ DDR RAM. You would actually get a much better boost in performance.

Are athlon XPs spec'd to run DDR400 (200MHz FSB)?

no, i believe only the 3200+ has 200mhz fsb

 

[DJFuji]

Originally posted by: shady06

Originally posted by: DJ Fuji

Originally posted by: Superman9534
different speed DDR RAM can be used in the same system just as different speed SDRAM can be used in the same system. PC3200 DDR can be run at PC2100 speeds. They cant, however, run at DIFFERENT speeds, but the RAM itself is compatible as long as they are running at the same speed.

Most new boards have either a PCI/AGP Divider (1/4, 1/5, and 1/6 for 133, 166 and 200 FSB) OR a PCI/AGP LOCK which locks the PCI/AGP speed at a constant 33mhz/66mhz.

I dont think running a chip at 200x10 would be less stable then 133x15 as long as the chip is designed to go that high of FSB and you have 400MHZ DDR RAM. You would actually get a much better boost in performance.

Are athlon XPs spec'd to run DDR400 (200MHz FSB)?

no, i believe only the 3200+ has 200mhz fsb

I meant the CPU/motherboards. Are they designed to run at 200MHz FSB or is this just an overclocking thing?

 

[Corporate Thug]

Originally posted by: DJ Fuji

Originally posted by: shady06

Originally posted by: DJ Fuji

Originally posted by: Superman9534
different speed DDR RAM can be used in the same system just as different speed SDRAM can be used in the same system. PC3200 DDR can be run at PC2100 speeds. They cant, however, run at DIFFERENT speeds, but the RAM itself is compatible as long as they are running at the same speed.

Most new boards have either a PCI/AGP Divider (1/4, 1/5, and 1/6 for 133, 166 and 200 FSB) OR a PCI/AGP LOCK which locks the PCI/AGP speed at a constant 33mhz/66mhz.

I dont think running a chip at 200x10 would be less stable then 133x15 as long as the chip is designed to go that high of FSB and you have 400MHZ DDR RAM. You would actually get a much better boost in performance.

Are athlon XPs spec'd to run DDR400 (200MHz FSB)?

no, i believe only the 3200+ has 200mhz fsb

I meant the CPU/motherboards. Are they designed to run at 200MHz FSB or is this just an overclocking thing?

only certain revisons of nforce2 boards, ie abit nf7-s rev2 will run @ 200 mhz fsb but rev1.1 wont