FSB Bottleneck?

[fkento]

Is it just me or does it seem counter-productive to have a CPU running at 1 Ghz or higher if the FSB is only running at 100-133 Mhz? For example, a Celeron 1.2 Ghz CPU has a FSB of 100 Mhz which means the processor is running at 12 times the speed of the motherboard & DRAM! Doesn't that create a huge bottleneck? Is it smart to buy a CPU with a 133 Mhz FSB even if the processor speed is slightly less?

[hiredgoonz]

Yes it is a bottleneck and yes, in some cases, a CPU with a higher FSB will perform better than a faster CPU with a slower FSB...

The Celerons are a particularly sad example because they have no trouble running at a 133mhz FSB, that core, Tualatin, was originally going to be a P3, but then it worked out that the P4 was out and since Intel is only going to market one "performance chip" they crippled the Tualatin with the 100mhz fsb and called it a Celeron.

They needed to do 2 things: 1) keep the clock speed of the chip comparable to the Duron which is viewed as the competition even though the Duron blows the Celeron away, and 2) keep the chip slow enough that it wasn't viewed as performing on par with the P4

The original P4 was a dog, especially when not paired to the quad-pumped 100mhz bus. (ever see the performance numbers for the 1.3ghz P4? Just sad) Even the slower clocked P3 beat it in performance, so they just stopped making the P3 and ramped up the clock of the P4 since most people buy a computer based only on the numbers.

Even the new Northwood core at an effective 400mhz fsb is running into a bottleneck at the highest speeds (3ghz range) so expect a 533mhz fsb 4*133 to come out at some point to help out...for some good reading (in case my post isn't long enough http://www.PCGuide.com/ubb/wink.gif )check out:
http://www.tomshardware.com/cpu/02q1/020225/index.html

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[This message has been edited by hiredgoonz (edited 02-27-2002).]