PLEASE HELP ME WITH THE FOLOW QUESTION-i am using asus p4c800 m.board
i have 3 memory slots used by the following :
2x256 kingston hyper x 400 mhz pc3200
500x2 kingston hyper x 400 mhz pc3200

in the past i succeeded to run those ddr moduls up to 400 mhz dual channel . but now the bios configures has changed ;
i am running now on 320mhz single channle!!!!

please i need just right clocks values to enter them into bios...
now i am using 2,4,4 clock..
what values can sattle it to 400 mhzdual channle??

...ummm what?

Dual channel uses 2 chips only.... and like dradoc said: ...ummm what?

I think you should be more worried how you were able to fit 4 memory modules in 3 memory slots. Also, I'd like to know where you got 500MB memory modules... In all seriousness though, make sure youre using an even number of memory modules (2 or 4) and also that they are in the proper channels to run dual channel. Then i would suggest resetting your bios to defaults and see what values you are running at.

I agree. Make sure the like modules are in the right slots. Boards are usually setup
1 and 3
2 and 4
for dual channel use. Refer to your motherboard manual to make sure. So if i am correct, the 256mb sticks should be in slots 1 and 3, while the 2 512 sticks should be in slots 2 and 4.

Check your processor speed. Make sure it is running at the correct speed. If not, maybe your FSB somehow got turned down.

All Memory has preprogrammed standards that it will run at. A bios reset, as suggested by agentsmith, should solve those problems as well.

I have seen some motherboards that access memory more slowly when they have 4 modules versus 2. My brother went to upgrade his HP to 2GB. He first tried adding 2-512MB modules I had sitting around it went from 400MHz to 333MHz. He upgraded to using only 2-1GB modules and it is mow running at 400MHz. By using 4 modules on that machine memory access and video processing were actually slower for him. So, sometimes going to 4 memory modules can slow you down.

If your board has an Intel chipset (no - I didn't bother looking it up; that's the OP's job), I've seen some of those that support asymmetric dual-channel mode. For example if your 2x256 MB sticks were in one channel and a single 512 MB stick was in the other channel, it might be possible to still set things up as dual-channel.

Definitely slow timings down, though, so that you can eliminate complications to the issue.

One reason 4 memory sticks might be slower than 2 is if the second set of sticks was a slower speed and he didn't realize it. The mobo will set the clock to the slowest memory

One reason 4 memory sticks might be slower than 2 is if the second set of sticks was a slower speed and he didn't realize it. The mobo will set the clock to the slowest memory

from the writer of this problem!!!!
first , thank a lot!! for all great professional answers!!!

i will make the following task as you advice me:
1. check fsb set to 800mhz
2.check the modules if the installed on correct slots ...
3.reset bios to defualt

again thank you a lot for help , i am new user here on this forum.
god bless u.k. the the irish beer!!!!!!!

Professional = paid for their knowledge. I assume that some of the above posters can be looking forward to receiving some $$$

asking for professional answers and not giving professional data = what you got, just a little help. In my exp though most boards don't handle the asym dual channel very well if at all. And in all seriousness a few clock cycles is not really going to net much increase. but I digress.
find 4 matching modules and you may get better results

good luck