I want an opinion on what I was told on a different forum

[dragonfly522]

Hello, I have been told that running any higher speed of RAM than what the fsb is running will not be effective at all. Is he correct? Also, I was told something to the effect of fsb speed is showing only half of what the listed speed of the ram that you buy is, so 400 Mhz fsb will match a 800 Mhz ram stick, if the first thing that this guy told me is correct. One more thing - how do I find out which motherboard I have and is there a web site which tells all of the CPUs compatible with each model of mobo?

 

[jsphdickens]

Running the program below will give you useful system information such as your motherboard model

Once you find out what motherboard you have, search for it on google to find out what socket it has, which will tell you what processor you can use. For instance, if you have a Gigabyte motherboard with Intel's Socket 1156 you can use intel socket 1156 processors.



http://www.belarc.com/free_download.html

 

[jaquith]

Welcome Newcomer!

DDR {Double Data Rate} http://en.wikipedia.org/wiki/DDR3_SDRAM will indeed "show up" as 1/2 rated speed; e.g. 1600 MHz will show 800 MHz in DRAM Frequency ~ CPUz

FSB {Front Side Bus} http://en.wikipedia.org/wiki/Front-side_bus#Memory Yes and no, {OC = No it allows DDR/FSB increase} in the relationship DRAM MHz vs FSB is either 1:1 or 5/4, BUT FSB is the "product of the width of its data path, its clock frequency (cycles per second) and the number of data transfers it performs per clock cycle."

"Usually (Memory Divider) × (Front Side Bus Frequency) gives I/O Bus clock of the memory. Memory clock then determines the final operating frequency or effective clock speed of memory system depending upon DRAM types (DDR, DDR2 and DDR3 SDRAM).
By default, FSB speed and memory are usually set to a 1:1 ratio, meaning that increasing FSB speed (by overclocking) increases memory speed by the same amount."

Use CPUz as referenced to determine the MOBO, once you determine the "MOBO" then you can work backwards to determine supported CPUs by going to the Mfg site.

 

[gamerk316]

In motherboards where you can set non 1:1 FSB-RAM ratios, increasing RAM speed CAN cause a slowdown of the system. As a general rule, you want to keep some ratio with the FSB (5:4, for instance) for maximum overall performance. [Hence, why the FSB no longer exists; its a system bottleneck]

In motherboards where you can't set a non 1:1 FSB-RAM ratio, increasing the speed of the FSB will increase the speed of the RAM to match. This CAN lead to instabalities if either component is overclocked too much.

 

[dragonfly522]

sorry, but I am not sure that I get the whole picture. According to what I have read in a different thread, the RAM default setting is 2X the fsb speed, therefore fsb speed of 4000MHz would be optimal at 1:1 at 4000MHz of RAM or 16,000 MHz, 16,000MHz being what the specs would read on an ad for the product. I read that the phenom II x6 1055t that I want has a fsb of 4000MHz. The ddr3 RAM is available at OC speeds of 2000 Mhz at the most, I think, so what am I missing? If I'm not missing anything, how does a much faster fsb affect a much lower speed of RAM? Isn't there a mass amount of speed that is dormant in the fsb? I feel stupid.

 

[jaquith]

DDR speed = {BCLK X Memory Multiplier} or a product of Base Clock and a multiplier.

DDR 1600 MHz = {133.33 MHz X 12} by default the Memory Multiplier is 8 or 1067 MHz.