Originally Posted by Moonhill
May I have some advice to get the most of 1.8A (FSB 400/ L2 512) with Asus P4P800?
I purchased 2 sticks of 256 DDR400 PC3200 ram for dual channel. Dual channel makes difference? Is it possible to set up dual channel with 4 sticks of 256 DDR400 (total 1G)? Thanks
Your Intel cpu is quad pumped meaning that every cpu clock cycle it sends 4 instructions. So even though the FSB (Front Side Bus) speed is 400MHz it's effectively running at 100 MHz (400 MHz / 4).
As for your DDR (Double Data Rate) memory modules... every clock cycle they send 2 instructions. PC3200 ram is rated 400MHz but since it has a double data rate then the effective clock speed becomes 200 MHz (400 MHz / 2).
So what do you make out of all this ? Your ram is running twice as fast as your cpu. So your cpu is limiting the performance of your machine.
Intel based systems give out the best performance when the cpu runs as fast as ram modules (this is called a 1:1 FSB:RAM divider). Although it wouldn't hurt to have your ram running faster than your cpu (but that's not the optimal configuration).
So technically you should try to pump your effective FSB speed to 200MHz (although I doubt it'll go so far).
's a link to download your Asus P4P800 mobo's manual for more details on the Bios sections.
Go into your Bios and look for "Jumper Free Settings" and set it to "Manual".
you will then have the option to configure your settings with more precision.
Gradually raise your FSB in small steps (3 to 5 MHz at a time) starting from 100. Save your settings and reboot each time then once you get into Windows you should check your machine for stability.
As for your dual channel questions.
Yes dual channel makes a big difference as it doubles the bandwidth of your ram.
And yes you can use dual channel mode with 2, 3 and 4 sticks if your mobo supports dual channel.
Usually mobos that support dual channel have onboard ram slots with two different colors.
's a link to help you understand the different possibilities for running in dual channel mode.
Theoretically to make use of dual channel more you should do three things:
1) Buy a mobo that supports dual channel.
2) Buy identical sticks of ram.
3) Install the ram modules in the appropriate memory banks + slots (usually you should install your identical sticks in the slots having the same color). So if you have two identical 256MB sticks and two identical 512MB sticks and you want to run in dual channel mode... then you should install the 256MB stick on the black slots and the 512MB sticks on the blue slots for example.
The following quote is taken from PCstats.com
Dual channel memory works just like RAID on a HDD. Basically the two memory controllers stripe the data accross/between both sticks of RAM to allow faster access. Functionally in single channel memory the one memory controller just assigns address to the RAM and realistaically sees one 'chunk' of RAM being the sum of all the sticks. In dual channel each controller address its stick of RAM independently and allows each stick to be access simultaneously.
Last but not least, check this
link for an article about overclocking a P4 1.8a that reached speeds of 2.4 GHz (with an FSB at 133 MHz).
Also check this
great guide on how to overclock.
Hope this helps !