Introduction
Over the past few months we have seen Intel becoming more and more competitive in the desktop CPU market. Currently they have the stronghold over AMD with the Pentium 4. The CPU was launched over 18 months ago which is a long time in the CPU world. AMD had stomping CPUs out there which were not going to be beaten easily and with the AMD pricing points it was going to be hard for Intel to get the upper hand. Intel released the P4 but the performance didn't "give" what we was needed to the market - it was more of a case of getting the market to adopt the new architecture and other new factors - such as Rambus and a new PSU/Mainboard - 100% new.
Intel had the P4 on the market at the 1.4/1.5 GHz speeds which were a fair bit higher than AMD processor speeds on the market and AMD fought this with the creation of the PR system. i.e. 1.4Ghz = XP1600 and so on. Intel have recently hit back with the release of the 0.13 Micron technology and in this iccarnation we have the Northwood breed of CPU - this meant the core was smaller, you got faster clock speeds, cooler running, more cache [They introduced an extra 256KB of L2 Cache at this point]. After the initial release of the 2.0A and 2.2, they created a modern day Celeron 300, the 1.6A. You can pick up a 1.6A today for around £120 and quite easily hit speeds in excess of 2.1GHz. This is the most cost effective form of speed.
Today Intel release a modification to the Northwood range of CPU's and it's this that we are covering. Intel have ramped up the front side bus speed of these newest Northwoods to 133MHz (533MHz quad pumped). The new CPU's debut at 2.4GHz and 2.53GHz and it's the latter that Intel are using to lay claim to the quickest consumer processor crown.
As we have already talked about when Intel introduced the P4 they released a new chipset - the i850. This has been around for a long time and seen the P4 for its life so far but now it is time for it to hang-up its boots and move on. The 850 took the 100MHz bus speed and quad pumped it allowing you to have "400Mhz" of FSB. This coupled with Rambus memory gave huge bandwidth (3.2GB/sec theoretically) to the desktop PC. Intel have also released 850E today this is basically 850 but with the support for 133 Bus P4s. There has recently been a few motherboards on the market such as the latest TH7-IIs which support the new 'B' CPUs and have the 133MHz clockgens present.
Today sees the end of the 100Mhz P4s as Intel will only be releasing 133 bus P4s from today onwards. This means that some users will have to get a new mainboard and will leave some people with a bit of a cost. There is no change to the chipset bar a few minor changes to make it pass Intel's strict testing policies. There has been a lot of talk of PC1066 bus memory on forums and newsgroups but the 850E does not support Rambus' latest PC1066 memory. The memory does work in the boards but it isn't needed to run with the new processor - it has full support of the PC800 modules. The limiting factor (which currently isn't exactly limiting) is the memory - the latest Samsung modules do 1066 speeds, and some do more. But if you wanted to get 1066 memory you can - even though they aren't the cheapest modules on the market.
The Pentium 4 Northwood 2.4B looks exactly the same as Northwood 2.4A CPU - same packaging, same pin outs, but it has a FSB of 133, and a multiplier of 18. This FSB change which is present here is more than just an FSB change. The bandwidth which is present between the MCH on the mainboard and the CPU goes from 3.2GB/s to 4.26GB/s, but since 850E supports PC800 it means that the board has to change the memory multiplier from 4Xs to 3X. This means that the bandwidth which the memory has is only 3.2GB/s even though the CPU to northbridge has gone up by 33% you are increasing the size of one end of the equation but the other end is staying the same. The main idea is to keep the entire system in flow and you want the memory and other interfaces to run at the same speed or faster than the CPU. But the P4 running at 2.4/2.53 this is a lot faster than the rest of the system - this is something consumers seem to miss when spec'ing up there latest system - the CPU isn't always the most important part. The speed of your hard drive can have a huge affect on the overall system performance. It is like putting a huge engine on the back of a small boat - it is pointless. You are wasting all this possible speed.
This CPU has 4.26GB/s of possible bandwidth but with the
throttling of the memory bus speed is a factor until 1066 memory
is available and full support is available on the market for this. There are a lot of factors which affect the bandwidth
within the system. The clock speed is the main factor here -
if the clock speed increases the more information needed increases - if the
clock cycles can not be fed fast enough with enough data then these are wasted
clock cycles.
Most people do not need the speeds we are talking about here - meaning most
people do a bit of surfing - play a few games but nothing which really pushes the CPU. The
latest 3D Game such as Doom III (When iD release it) will push your system to
the edge and this is when some people may need to upgrade, as these are heavy
calculation and load bearing games and can easily take a lot of power and
bandwidth.
