Intel 3.46EE and 925XE Chipset - 1066 MHz FSB
Introduction, Processors and Chipset
It's no secret that AMD's Athlon 64 processor has been making a game out of out performing the Intel P4 line of products for some time. I use the term "game" to point out exactly where the Athlon 64's have been the strongest -- in gaming applications. When the Athlon 64 first came on to the scene, Intel's P4 line was leveled by the performance the on-board memory controller and K8 core gave AMD. Intel's launch of the Extreme Edition processors, Northwood cores with 2 MB of additional L3 cache, were meant to plug the leak in multimedia applications and games where the longer pipelines of the P4 architecture (and then following with Prescott) held it back. The EE's didn't make up considerable ground, but the Athlon 64's were still winning the race.
If you are a processor enginneer trying to get life out of a core design, you have only a few options really to increase the performance for your design. You can add cache, increase the frequency, or increase the bus speed. Intel has already added cache with the EE processor line and they have continued to increase the frequency on the P4 line as well, up to 3.6 GHz at last check. In most benchmarks, and in particular gaming, the Intel CPUs and platforms are still behind the AMD counterparts, and thus, today, we see the third attempt from Intel as an increase in the front-side bus speed to 1066 MHz.
The Intel 3.46EE Processor
The new Intel 3.46EE processor is still based on the Northwood core of the P4 line and is also still manufacturered on the 130nm process. It seems that Intel isn't going to be making the transition to 90nm on the EE line, as the Northwood core its based on, gives Intel two chances to out pace the AMD competition -- Northwood and Prescott. It also continues to have 2 MB of L3 cache that the other P4 processors don't have.
Intel 3.46EE Processor
What has changed is the FSB that the processor supports out of the box. The other recent P4 have all used an 800 MHz FSB (200 MHz quad-pumped). This iteration brings about a 1066 MHz FSB (266 MHz quad-pumped) to increase the memory access speeds. The DDR2 memory in the previous processors did run at 533 MHz (266 MHz DDR) but the processor bus was running asynchronously with the memory bus. Frequent AMD users will recognize the idea of "Bus + 33" or similar settings on the K7 chipsets when DDR400 was first released. It was the same principle for the Intel DDR2 launch. Now Intel is able to run the most efficient memory method on the DDR2 533 MHz speed -- synchronous.
The frequency on this new EE processor is 3.46 GHz and runs at 266 MHz x 13 multiplier where the previous 3.4 GHz EE processor ran at 200 Mhz x 17. Intel has actually done what many in the PC enthusiast community have been doing on the Athlon 64 line -- lower the multiplier and increase the FSB for faster memory access with a similar total frequency. This allows Intel to increase the performance of the chip without having an increased problem with yields, as the frequency stays the same (or nearly exact). Heat dissipation and power consumption also remain unchanged. All they needed now was a board that officially supported this new FSB speed.
The Intel 925XE Chipset
And that is where the Intel 925XE chipset comes into the scene.
(Click to Enlarge)
Pictured here is the supplied Intel 925XECV2 motherboard based on the new 925XE chipset. Not much has changed on the chipset and in fact, if you look at it compared to the Intel 925XCV motherboard we used in our intial review, you can see they are identical. So then, what is different? Official support for the 1066 MHz FSB is all that has changed on the core logic. Intel isn't making any additional claims than that, and its great to see honest and earnst marketing people!
On the memory side, we did get some new memory from Corsair for our testing that supports new, lower memory timings on the DDR2 533 MHz speeds.
Corsair XM2X512-4300C3PRO Memory
The new Corsair 4300C3PRO modules support timings of 3-3-3-8, the fastest we have seen supported on DDR2 memory yet. We used this memory at those timings in our benchmarks, so you are going to see the increase of the FSB as well as the new memory timings coming into play in our results.