pc3200 ram showing speed of 333mhz in bios

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I installed a gig of pc3200 kingston ram into a dimension 4600. The system is suppose to support 400mhz, but it is showing speed of 333mhz in bios. I removed the old ram, and I'm sure the 2 sticks are what they are suppose to be. Any way to make it run at 400mhz? Thanks in advance.
 

Didou

Posts: 4,190   +11
Have a look in the BIOS, make sure your CPU's FSB & your Ram speed is set to 200mhz. It might have been reset to a failsafe value when it detected the Ram change.
 
hi

The bios stinks. All it shows is that the FSB is 533mhz (3ghz processor), and it shows the ram speed as 333mhz. No option to change anything.
 

Didou

Posts: 4,190   +11
Well are you sure your CPU is supposed to run off a 133mhz (533) FSB ? When I google for a Dell Dimension 4600, most websites say it has a 200mhz (800) FSB CPU on it.
 
Yes, most of the 4600s are 800FSB, but some are 533 (including mine). I wish I would have spent a little extra money, but too late for that :p. Does this mean my ram can't run at 400mhz?
 
CPU-Z shows this:

CPU section: Core Speed: 3059.1 mhz
FSB: 133.0 mhz
Bus Speed: 532.0 mhz
Memory section: Frequency: 166.2 mhz
FSB:DRAM: 4:5

Mainboard section: Mfct. dell
Model: 0F4491
Chipset: Intel i865P/PE/G/i848P Rev: A2
Southbridge: Intel 82801EB (ICH5)

BIOS version: A12

Hope I included the right stuff.
 

Didou

Posts: 4,190   +11
Good enough.:)

I'll try to keep this simple. Your CPU has a 133mhz FSB (533 quad pumped). It is capable of using 4.2 GB/s of memory bandwidth. When you run a dual channel configuration, you only need to run PC2100 Ram (capable of providing 2.1 GB/s of bandwidth hence the PC2100 name) to meet those needs as each memory channel provides the CPU with 2.1 GB/s (2.1+2.1 = 4.2 GB/s).

So when you're running your Ram at 333 or PC2700, you're already providing your CPU with more bandwidth then it can use (2.7+2.7 = 5.4 GB/s). If you would increase the Ram speed to 400 or PC3200, that would just mean more wasted bandwidth (3.2+3.2 = 6.4 GB/s) & you wouldn't even notice the difference.
 
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