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Question about FSB

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I have a DFI Lanparty UT NF4 Ultra-D


Now, I am currently attending a networking course, and part of the course is an A+ class. My teacher keeps saying that your system is only as fast as your slowest link. For example, if I have RAM running at 400mhz and my FSB is only at 200mhz, my RAM is only running at 200mhz. Now, I do have 400mhz ram, and my motherboard by default runs at 200mhz FSB. Now, I told my teacher what type of motherboard I have, I told him that my motherboard could go higher than 200, and I asked him, if I lower my multiplier, and up my FSB, would that be more efficient? He said that it should be. Now, I tried that, and it didn't work. From the research I have done, I think the reason it wasn't working was because of the HTT and LTD factors of A64. Am I right in assuming this? Will I have to change other setting to at least get my FSB to 400mhz? Or is it just not doable? What do you guys think? Did I misinterpret something my teacher said about slowest link? Or is he wrong about certain things? Is he not up to date with A64 technology?



Thanks in advance for all the replies XD

Also, it would be greatly appreciated if somebody could refer me to detailed documents about HTT and LTD

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welcome to the boards


200 board/cpu speed,


Ram is running 400 (DDR, double data rate, rise and fall of the cycle, so it runs double speed)


when you up the HTT/FSB, the same will happen to your ramski, ie, raise it to 220, ram is running 440. thus the ram dividers to help with even higher HTT/FSB runnings, helps keep the ram from fubaring the overall clockage.


there is a definative overclocking guide here at the forums, do a quick search and get to reading, then when you go back to class, you can explain it all to your instructor and classmates..and it covers all the questions you asked and a WHOLE lot MORE....



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Your teacher has not told you the complete story.


What he means is,


On the older generation AMD CPU's (socket A),

The CPU has a direct link to the northbridge.

Assume this link is 200Mhz, EG can send data at a rate of 200 times a second.


Northbridge then has a direct link to the memory controller/memory.

Say this link is 400Mhz = EG can send data at a rate of 400 times a second.



The CPU is what determines how much data is being sent.

Therefore if the CPU to northbridge link can only push out at a rate of 200 times a second there is no point of using 400Mhz memory.


The northbridge to memory controller link will have a quicker access time but the overall system bandwidth is limited because the CPU cannot deliver at the same rate.


So in this example the memory bandwidth is limited due to the CPU FSB.



But in the newer cpu's such as the socket 754 and 939 and AM2, the memory controller is directly inside the CPU.


The CPU communicates directly to the memory.

And the CPU communicates directly to the northbridge.

It has 2 links.


This means that the memory bandwidth limitation has been removed.


Your 939 CPU has something called the HTT, hypertransport link.

This runs at 1000Mhz (2000Mhz) and is the northbridge to CPU link speed.


Based on this, what you teacher said is wrong.

You do not need to lower your multiplier and up the FSB.


The FSB is no longer putting a limit on the system BUS and memory performance.

Both are now independent from each other.



Due to this change, the memory controller is now very efficient and the CPU can push data at rate above 3200MB/s and dual channel mode is required to handle this throughput. (6400MB/s).


If you overclock a single core CPU to 3Ghz you would definitely need to run the memory at 250Mhz and expect to see it push data beyond 7000MB/s.



So tell your teacher that you have a 939 CPU which has an integrated memory controller.

Independent FSB (now called HTT BUS) and memory BUS.

And that the FSB limitation is a thing of the past.



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