Need some help with Ram vs FSB

jeremyhelling

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May 3, 2005
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Hello everyone, I've been lurking for a while now and wanted to register and post up a question I have.

I've got a Dell Dimension 8400 and just ordered 4x512mb 533MHz RAM for it.

My packing slip for the 8400 says that the processor has 800fsb and yet it still says it supports 533MHz RAM. My question is two parts. The first is, will it bump to 1066fsb to support the RAM and if not, would I have been better off going with 400MHz RAM as it will perform the same with my computer? Here's a link to the tech specs on the 8400 that Dell has posted:

http://support.dell.com/support/edocs/systems/dim8400/SM/specs.htm#wp1052308

I don't see it listed on there, but my 8400 has a P4 630. Thanks.
 

CrucialLabs

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May 20, 2004
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The system itself with the current processor will handle 400MHz memory for a 800MHz FSB. The motherboard has the potential to use a faster processor which will allow you to use the 533MHz memory for a total of 1066MHz FSB.

You can use the 533MHz memory and run it just fine in your system but it will run at 400MHz unless you plan on overclocking. If you do not plan on overclocking then buying faster memory then the FSB speed will not hurt you but there is really no reason to go that high.

Just some things to think about.

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jeremyhelling

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Thanks for the reply. So, as it is I can't take advantage of the 533MHz RAM then. I realize worst case scenario it'll run at 400MHz but I was hoping that for some reason this bad boy would run 1066 if the right RAM was added.

Looks like I'll read the overclocking section to see how easy/hard it is to overclock the fsb on the 8400.

On another note, 200MHz runs at 400MHz due to the double data rate stuff, does the same apply if you run four dims of RAM? So, if a guy runs two @ 400MHz how does this affect the speed if you run four of the same RAM?? Still 400MHz? Thanks.
 

over_c

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It may be possible for you to change the memory ratio. If the ratio is set at 1:1 (FSB:Memory) then the memory will run at 400 MHz. If it is set to 3:4 then the memory will run at 533 while the FSB still runs at 400.

I don't know if the Dell BIOS will permit you to make this change, but you could try and find the option.
 

BrentUnitedMem

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Sorry, it's a BIOS setting that permits this change.

Dell is pretty much sold as is, with little to no room for overclocking.

I believe if you do overclock a Dell, you might void the warranty- you may want to check this out.

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