Because they use the same packaging and have the same integrated heat spreader design, the new Core 2 Extreme QX9650 looks just like the QX6850 it is supplanting at the top of Intel's desktop quad-core processor line-up. If you flip it over, however, there are some things that differentiate the newer 45nm processor from its 65nm counterpart.
Although they may use the same socket and thus have the same 775 pads on their underside, the surface mounted components on the Core 2 Extreme QX9650 (right) are arranged in a different configuration. This isn't an earth shattering discovery by any stretch of the imagination, but we thought you'd like to see the differences first-hand nonetheless.
The information provided by CPU-Z also shows some of the main differences between the new Core 2 Extreme QX9650 and its older 65nm counterparts. The core name is properly listed as Yorkfield (Wolfdale is the dual-core desktop variant), the stepping is listed as '6', process is correctly listed as 45nm, and SSE4 instructions are listed as well. The dual 6MB L2 cache of the each dual core die on the processor is also correctly identified. It's on the Cache tab that another of Yorkfield's interesting changes are listed. As we've already mentioned, in addition to increasing the size of the L2 cache, Intel has tweaked the configuration to be a 24-way set associative cache - Conroe and Kentsfield are 16-way. The L1 cache remains 8-way set associative on Yorkfield.
We're sure many of you are wondering just how much clock speed headroom the Core 2 Extreme QX9650 has left under the hood, so we spent some time overclocking our sample as well.
Using a stock, Intel cooler and an Asus Blitz Extreme motherboard based on the P35 chipset, we set out overclocking the QX9650 by first increasing its voltage to 1.4v. Then we increased its multiplier and found that 11 was the sweet spot - with the multiplier increased to 12, which resulted in a CPU clock speed of 4GHz, the system wasn't completely stable. Then finally we slowly increased the FSB frequency until we found our particular processor's peak, stable overclocked speed. Ultimately, the CPU hit an impressive 3.9GHz.
At that speed, the processor idled at only 37ºC and under load it never broke the 60ºC mark. We also noticed that the CPU's temperature dropped rapidly when entering the idle state. It's clear that even at this relatively early stage, Intel's 45nm manufacturing process is healthy and ready for prime time.