ram speed question

dixsey

i had 512 mb of 333 mhz ram and then i added 1 gb of 400mhz ram(1.5 gb total) which ran at the slower 333mhz (nothing wrong there)but last night i removed the 512mb of 333 mhz leaving me with 1gb of 400mhz ram but when i check the speed of my ram in pc mark04 and 3d mark 05 it says its only running at 333mhz any ideas please thanks guys

jessy

Whats the FSB on the Motherboard running at?

dixsey

jessy wrote:

Whats the FSB on the Motherboard running at?

in cpu z it says my cpu fsb is 133.00 mhz cant see anything for the mobo how would i find out my fsb on my mobo? thanks

jessy

Check your Bios to see what speed the Ram is set to.

dixsey

jessy wrote:

Check your Bios to see what speed the Ram is set to.

excuse my ignorance but how do i check my bios for ram speed,im new to this thanks

jessy

Is your Machine Retail (i.e. dell,Compaq,Acer etc)? if so you probably wont be able to change it.

On start when you see a display saying press certain key to get into BIOS. there shoud be an option to select speed of ram.

dixsey

jessy wrote:

Is your Machine Retail (i.e. dell,Compaq,Acer etc)? if so you probably wont be able to change it.

On start when you see a display saying press certain key to get into BIOS. there shoud be an option to select speed of ram.

yeh i got into the bios using f12 at start up and when i check the memory speed its 333 mhz and i cant change it,but it says in the manual that it supports 400mhz ram(strange)

jessy

increase the FSB a little bit to gain more speed.(in no more than jumps of 5 till you max out.)

dixsey

jessy wrote:

increase the FSB a little bit to gain more speed.(in no more than jumps of 5 till you max out.)

dont think i can its a dell 4600

dixsey

any idea why my ram is only running at 333mhz even though its 400mhz ram and my rigs manual says it supports 333 and 400mhz ram thanks

Col_Loki

Your CPU is running @ 133mhz which means you wont be able to use the DDR400 mhz Ram at its rated speed (you need 200mhz FSB to do this). The support for DDR400 is used with a P4 "C" which has the 800mhz FSB (or 200mhz x 4).

Basically your CPU's FSB isint fast enough to take advantage of the Rams extra speed potential.

po0k

The board's chipset might be able to run the FSB at 166Mhz FSB, and the ram at 166Mhz, but your processor might only support max of 133Mhz (effective 533Mhz FSB with P4s - 4x133).
Running the FSB and mem clocks out of sync (one faster than the other) is not recommended, as the faster one will just go into wait states whhile the other catches up, and while you might have better latency timings, the performance gains aren't really there.

You're pretty much stuck with 133FSB and 166MEM I'm afraid



"Duuude! You got screwed!"

dixsey

thanks for the help i might aswell stick my 512mb ram back in so