Memory/CPU FSB question?

[SmileM]

I have already purchased the RAM. I have 2 separate
packs KVR333X64C25/512

The memory chips on the modules in the 1st pack are: Kingston D328DL-60 0319PT16
and on the other module chips are: Kingston D328DL-60 0318PT16

I will be using ASUS P4P800 Deluxe Mobo. It supports memory speed of 320 when using DDR333 memory.

What will be my true memory speed? (640Mhz?) I think I'll have to use 3Ghz CPU with FSB 533 because it has HTT and my ram will be able to work fast enought to match CPU FSB :/

Correct me if I'm wrong

no I think you got it wrong, from my limited understanding, cpu fsb is rated at 2x1 meaning your cpu setting is 133 then the actual speed is 266

memory speeds are 1X1 meaning that if your using ddr 333 in the same system then its actually going to be running faster than your cpu. Wich by the way doesn't hurt anything.

[Telexen]

Intel confuses people with the Quad Pump technology...you CPU's FSB is 533mhz; that means the system bus is 133mhz, which is exactly what the memory's bus speed is, so it runs at 266mhz.

[SmileM]

What about 800FSB CPU? I much performance I will loose with DDR333 running in dual mode? I think it will be a few percent

But then again I can perhaps upgrade the ram to DDR400 in the future and having CPU capable of 800FBS doesn't hurt

[Telexen]

If you go with the 800mhz FSB CPUs you'll need 400mhz (PC3200) DDR RAM

[beppodmime]

P4's work differently with memory bandwidth than Athlon XP's do. They run on a quad pumped CPU FSB, which is capable of using more raw memory bandwidth than the Athlon XP's double pumped bus. You've already got the right idea with being able to use PC3200 in the future, and having a little upgrade headroom is never a bad idea. However, you don't NEED to go with a 533 FSB processor. You won't be losing performance, per se, but rather, not using the chips bandwidth capabilities to it's full potential. The 800 MHz part will probably STILL outperform a 533 MHz FSB part without much effort, in a near clock for clock basis. The 800 FSB processors will use all available memory bandwidth from the PC2700 in dual channel mode, as it would the same with PC3200. The actual limit to how much bandwidth the P4 can utilize tops out at somewhere between an 800 MHz and 1 GHz FSB (remember, this is all quad pumped, meaning 200 and 250 REAL MHz, respectively.) In my honest opinion, you may as well go with an 800 MHz FSB processor, especially if you are already planning on upgrading to PC3200 memory later on. Cause when you decide to upgrade memory, you're going to want to upgrade the 533 FSB processor, too, in order to take advantage of that board. And then you'd have already wasted the money on an older part.

My advice, stick with an 800 MHz FSB processor, go with whatever memory you already have and the motherboard you want, and then if you get an itch, you already know what to upgrade. Of course, you could always buy memory rated higher than PC3200 and overclock the crud outta the FSB, but that's up to you.

[SmileM]

Originally posted by beppodmime
P4's work differently with memory bandwidth than Athlon XP's do. They run on a quad pumped CPU FSB, which is capable of using more raw memory bandwidth than the Athlon XP's double pumped bus. You've already got the right idea with being able to use PC3200 in the future, and having a little upgrade headroom is never a bad idea. However, you don't NEED to go with a 533 FSB processor. You won't be losing performance, per se, but rather, not using the chips bandwidth capabilities to it's full potential. The 800 MHz part will probably STILL outperform a 533 MHz FSB part without much effort, in a near clock for clock basis. The 800 FSB processors will use all available memory bandwidth from the PC2700 in dual channel mode, as it would the same with PC3200. The actual limit to how much bandwidth the P4 can utilize tops out at somewhere between an 800 MHz and 1 GHz FSB (remember, this is all quad pumped, meaning 200 and 250 REAL MHz, respectively.) In my honest opinion, you may as well go with an 800 MHz FSB processor, especially if you are already planning on upgrading to PC3200 memory later on. Cause when you decide to upgrade memory, you're going to want to upgrade the 533 FSB processor, too, in order to take advantage of that board. And then you'd have already wasted the money on an older part.

My advice, stick with an 800 MHz FSB processor, go with whatever memory you already have and the motherboard you want, and then if you get an itch, you already know what to upgrade. Of course, you could always buy memory rated higher than PC3200 and overclock the crud outta the FSB, but that's up to you.

Thanks for your helpful reply. I'll go for the 800FSB processor

[beppodmime]

Just an added note, if you did decide to go with a 533 FSB part, the max memory speed you can run is PC2700 speeds. The BIOS won't let you run PC3200 at PC3200 speeds with a 533 FSB part. It will, however, let you run PC3200 with an 800 MHz FSB part.

And you're quite welcome. Anytime you need buying advice, or any kind of help with any kind of tech support issues, it's been my experience that it's almost always worth while to pose the question in these forums. There are plenty of helpful, knowledgeable people who browse here on a regular basis.

And, since I forgot in my earlier post....

Welcome to TechIMO!