Intel QX9770 1600MHz FSB Launch & Review - PAGE 1

Intel has done it now.  Before the Penryn aka Yorkfield chips have even hit the streets they've gone and released yet another chip for the press to go over. Today we take a look at Intel's new poster child, the QX9770 Core 2 Quad Extreme Edition. This newborn Yorkfiled chip features a blistering 1600MHz FSB as its stock setting and runs at 3.2GHz!

Yes kids, that means that those of you that don't like to overclock your precious processors can now buy an extreme edition quad core Penryn QX9770 and feel safe in the knowledge that you pop it into a motherboard - that officially or unofficially supports a 1600MHz FSB - and you can enjoy the power for four cores at 3.2GHz without fiddling!

Above you see proof... CPU-Z showing you that this QX9770 is running at 8x400 MHz, and the multiplier field shows you that the default multiplier is eight. What CPU-Z does not show you is that this processor is also unlocked upwards - it supports multipliers up to 31 as a matter of fact!

Since this is our second Penryn article, we are not going to go over the changes to the Core 2 microarchitecture - for more on Penryn, take a peek at our Penryn QX9650 Launch article.

Why FSB matters

For years now, Intel has been having scaling issues due to still being based on a front side bus. This was exacerbated by the FSB officially being limited to 1066MHz until relatively recently; however when Intel decided to take the breaks off, they did it in style... going to 1333MHz FSB with the P35 chipset, and shortly thereafter, to 1600MHz FSB with the X38 (at least semi-officially, for "official stamp of approval we get the x48 soon).  Now Penryn arrives first in 1333FSB (as in the QX9650 Extreme Edition) and today at 1600MHz FSB (QX9770 Extreme Edition).

Frankly, I would not be surprised if we saw 2000MHz FSB support before Nehalem and its CSI show up, but that is pure speculation on my part.

(Our P35 Launch and P38 Launch articles have more information on those chipsets)

Fundementally, the FSB limits how fast the processor can read and write data not only from memory, but also from PCIe and other devices. The FSB is also used to keep the processor caches coherent (in sync), and as GTL+ is packet oriented, there is also a certain ammount of overhead.

A good rule of thumb is that the maximum possible read/write bandwidth is approximately 90% of the FSB frequency multiplied by eight - that's why you will not see extremely high read/write bandwidth scores from dual channel memory setups until Intel goes to on-processor memory controllers with Nehalem.

Here is a handy table that will show you the maximum theoretical gigabytes per second transfer over the FSB, along with the practical maximum that might be reached with an incredibly good chipset:

As you can see the QX9770 has around 10% higher gigabytes/second transfer over the QX9650 at stock speeds.  You've already seen our overclocked results in the QX9650 launch review, but now let's put the QX9770 through its paces and see how it stacks up.