?
Solved

FSB speed limit

Posted on 2002-03-18
2
Medium Priority
?
267 Views
Last Modified: 2011-09-20
Currently, the FSB is 333Mhz , why can it go faster. Is it because the current bus it's not true 32 bit and it's  only 16+16 bit bus, hence the limitation to speed up to 1.0Ghz or something else.



0
Comment
Question by:hhheng
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 12

Accepted Solution

by:
pjknibbs earned 200 total points
ID: 6879201
I think you're asking, "Why can't FSB go above 333MHz?". Actually, the fastest FSB around is currently 166MHz--to get 333MHz they use trickery to transfer data on both the rising and falling edges of the clock pulses.

As for the reason, it's nothing to do with the number of bits, and PCI is true 32-bit anyway. (SDRAM is actually 64-bit in both its single and double data rate forms). The limitation is this: you have 64 separate data lines running between the CPU and main memory. Whenever you send signals down these lines you're turning them into tiny radio transmitters, and adjacent lines can act like aerials and pick up these signals, thus corrupting their own data. This effect gets worse as frequency rises, so basically there comes a point where you can't reliably transmit signals down a parallel arrangement.

This is why RDRAM was invented--since RDRAM is a serial system and uses very few wires, there's less crosstalk and the signals can go faster.

Oh, and if you're wondering how CPUs can go as fast as they do without encountering this problem internally, it's because the problem diminishes with the size of the wires involved--this is at least part of the reason why the trend in CPU design has been to smaller and smaller transistors.
0
 

Author Comment

by:hhheng
ID: 6879426
Wow.. you really know your stuff well.
Thanks and cheers..
Heng
0

Featured Post

Veeam Task Manager for Hyper-V

Task Manager for Hyper-V provides critical information that allows you to monitor Hyper-V performance by displaying real-time views of CPU and memory at the individual VM-level, so you can quickly identify which VMs are using host resources.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Moving your enterprise fax infrastructure from in-house fax machines and servers to the cloud makes sense — from both an efficiency and productivity standpoint. But does migrating to a cloud fax solution mean you will no longer be able to send or re…
Arrow Electronics was searching for a KVM  (Keyboard/Video/Mouse) switch that could display on one single monitor the current status of all units being tested on the rack.
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…
In this video, Percona Director of Solution Engineering Jon Tobin discusses the function and features of Percona Server for MongoDB. How Percona can help Percona can help you determine if Percona Server for MongoDB is the right solution for …
Suggested Courses

765 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question