Fluffeei

Distinguished
Apr 20, 2004
4
0
18,510
At the beginning of this week I tought I knew about computers. How wrong was I! I have an Asus P4S533 mobo and currently have a p4 2ghz on it. I found a bios flash on the Asus webite which enables it to support up to 2.8ghz. W00t! I am now shopping (mostly scan.co.uk and ebay.co.uk) for CPU's and I'd like some help.
1. What is the cache on a CPU (I mean what actually IS a cache and what's it do/how's it affect the performance)and would a 1mb cache be supported on a 2 year old board?
2. My mobo only supports 533 fsb, will it be able to _run_ an 800 fsb just at 533, or will it not run at all?
3. Finally what's the difference between a normal P4 and a "Prescott?"

All help is greatly appreciated.
___

I completed tetris...<P ID="edit"><FONT SIZE=-1><EM>Edited by Fluffeei on 04/19/04 05:29 PM.</EM></FONT></P>
 

Crashman

Polypheme
Former Staff
1.) Cache is memory physically located on the CPU, it's much faster than RAM and is used to "cache" instructions so they can be available imediately. With P4's it's necessary to have pleanty of cache in order to keep the data pipeline full. Any time the pipeline is empty, it causes the CPU to miss processing cycles. 512MB seems to be enough for the Northwood P4, 128k seems to be too little, and more than 512k provides very little improvement, hence the P4"Extreme Edition" barely outperforms the P4 Northwood on which it's based, while the P4 outperforms the Celeron by a wide margin.
2.) It would probably run, but at 2/3 it's speed. A BIOS problem could prevent it from working at all, but that's not very common. A 2.8C would run at ony 1866MHz in this condition. The old, rare 2.8B (533 bus) would run at full speed.
3.) Read THG's articles on the Prescotts. There's a new Prescott 2.4 (introduced for the low end of the midpriced market) with the apropriate low bus speed that MIGHT work on your board.

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