RAM Speed, Palimino and FSB

[Jericho]

My friends computer is a AMD Athlon Thunderbird at 800Mhz. With a 100Mhz Front side bus. Does this mean that his 133Mhz SDRAM is only going at 100 because that is what the front side bus is? Or does the RAM run independant of the FSB?

Is it the same for my Pentium3 550E (5.5x100), because I have 128Mb PC100 RAM and want to know if getting 128 of PC133 RAM would make any difference.

Also, why do some people say athlons have 200Mhz system clock or something like that, is that because they are using the FSB and doubling it because there is both input and output?

Also, when will the Palimino be out, will it be 133FSB and will it be SocketA?

Thanks

 

[mpjesse]

Even though the FSB is 100mhz (200mhz DDR) installing PC133 RAM does increase performance. But, leaving the bus at 100mhz is kind of silly- if it's a T-bird you might as well overclock the FSB to 133mhz (if the motherboard allows it).

People say 200mhz because the EV6 bus is better known as a "DDR Bus". Instead of sending data in one clock cycle, it does it twice. This doubles the FSB speed effectively. While the clock is running at 100mhz data is actually being sent at a rate of 200mhz. This also applies to DDR memory.

Well, rumors were out that the Palomino would be released sometime in Q2. It will have a 133mhz FSB and it will be socket A.

-MP Jesse

 

[Jericho]

But would you get more performance out of your RAM if the FSB is 133 rather than 100? What is EV6? If I purchase a duron 700, can I up the FSB to 133 with just a normal fan supplied with the computer(as opposed to some sub zero atomic cooling deivce) and it will work okay but much faster.

Also, what are the advantages of having a clock like 133x6 as opposed to 100x8?

 

[Guest]

The bus is 200MHz for all intents and purposes, it's not a 100MHz bus! 133MHz RAM still leaves 66MHz unused.

I AM Canadian.

 

[Jericho]

Well if the bus speed is 200Mhz for all intents and purposes, why did I put my Gigabyte GA-7ZX motherboard on 100Mhz Front Side Bus? That is what i don't understand

 

[yoda271828]

<b>The bus is 100Mhz!</b> As Jesse already said...

The bus physically runs at 100 million clock cycles per second! The differece between the Athlons' bus (called EV6, because it was borrowed from Alpha's EV6 design) and a PIII bus is that the Athlon bus transfers two bits of data per clock cycle. So, the bandwidth is the same as a bus that runs at 200Mhz that only transfers one bit of data per clock cycle. However since the true frequence is 100Mz it must be set to that.

The bandwidth of 100Mhz DDR is the same as 200Mhz, and greater than 133Mhz. That is why the AMD chips can take advantage of PC133 memory while the bus runs at 100Mhz DDR. You have to compare bandwidth, not just frequency.