Abit Is7 with P4 2.8b + DDR400 memory

[maddogatc]

I just bought an Abit IS7 motherboard with Kingmax DDR400 memory. I with to use my existing P4 2.8b 533 with this motherboard. Will the DDR400 memory work?
I know that MSI and ASUS indicate in their manuals that 533mhz cpu will not work with DDR400 memory on their 865PE motherboards. You would have to use PC2700(DDR333) or less.
Abit's manual says nothing on the topic other than it will support PC3200 and lower ram.

Any comments?

 

[jammydodger]

PC3200 will work in your motherboard but it could default down to a lower speed. Most new motherboards support a divider which will allow you to run the ram at different speed to the FSB. Im not sure if this is the case with the IS7 but I will try and find out for you.

If I were you I would buy 2x256Mb or 2x512Mb of PC3200, this will work on your board at lower speeds (PC2100, PC2700). It will also allow you to take advantage of Dual channel mode.

<font color=blue>I have far too much time on my hands</font color=blue>

 

[jammydodger]

I dont think your board supports the memory dividers you need, so you will have to run your RAM at PC2100 speeds (133Mhz DDR). Remember if you get dual channel that memory bandwidth will be doubled.
PC3200 is about the same price as PC2100 now so I will still get PC3200 simply because will be better to own if you upgrade in the future.

<font color=blue>I have far too much time on my hands</font color=blue>

 

[maddogatc]

So far I have bought 2x256 Kingmax DDR400 ram. I'm just waiting for information from the forum before I put the computer together. If the DDR400 will lower to the 533mhz cpu speed I may as well just keep it for when I upgrade to a P4C 800mhz cpu in the future. I was more concerned with compatibility problems running this combination with the 865PE chipsset vs PC2700 memory.

 

[Crashman]

You're waiting for information? Here's your information!

First of all, you have OK memory. Second, you'll want to do some manual adjustments for optimization!

Here's what I'd do: Set the FSB to 133 (533) of course. Set the RAM to DDR266 speed, with it mounted in slots 1 and 3.

Now that's underclocked RAM, but that setting should allow Dual Channel operation to match your CPU bandwidth, and with synchronous clocks.

Since your RAM will be underclocked, you'll have LOTS of room to play with TIMING. I'd try to get the timing to CAS 2, 2-2-2-5 at PC2100 speed, I'd probably start out with 2.85 volt DIMM to allow the highest settings. If 2-2-2-5 works, I'd then try adjusting the RAM voltage downward to find the lowest stable voltage, to reduce heat.

Of course, you'll have some room to overclock too.

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