Apart from the 200MHz clockspeed increase, the Pentium 4 2.40GHz is absolutely no different architecturally
than any other Northwood processor currently on the market.
The 2.40GHz part features the same 64-bit, 100MHz Quad Pumped Front Side Bus (effectively 400MHz), supplying the processor with 3.2GB/s of bandwidth to the MCH/Northbridge. Cache structure remains unchanged, as the excellent 2-cycle, 8KB First-Level Data cache remains, as well as the 12,000 micro-op First-Level Instruction cache. The 256-bit, 8-way associative Second-Level cache stays at 512KB as well, just as has been the case with all Northwood processors, and delivers a massive 77GB/s worth of L2 cache bandwidth. When operations can be stored entirely within the Pentium 4ís excellent caches, expect great performance.
Fig 2. The 2.40GHz Pentium 4 engineering sample as featured in this article. Featuring 130nm process technology and the first Intel CPU manufactured on 300mm wafers.
Core voltage for the new Pentium 4 remains unchanged as well at 1.50V, indicating that at 2.40GHz, the Pentium 4 isnít experiencing any real difficulties on the 130nm process. This is good news, as the 2.40GHz Pentium 4 is based on the same core stepping as all previous Northwood processors
, and despite this, we were able to run our sample up to over 2.60GHz with the stock heatsink and default voltage.
Intelís second steppings on a new die process have historically done much better than the initial steppings. For example, initial steppings (A2) of the Coppermine processors werenít good for much more than 750MHz at first, while the second (B0) stepping was able to reach much higher speeds (on the order of 933MHz) almost immediately. If history serves as any indication, and given that our sample ran at 2.60GHz easily, we would expect the next Northwood stepping to be able to produce 3.0+GHz processors with ease.
Those of you keen to get your hands on a second stepping will have to wait a bit, though, as weíve heard nothing from Intel about a new stepping yet, and word typically leaks out at least a month or two before processors built on the new stepping actually make it to the market. Nevertheless, suffice it to say the 130nm ramp seems to be going quite well for Intel. We would expect that the upcoming 2.533GHz part will likely use this same stepping initially.