Intel Core i7-860 Lynnfield Processor Review - Best value in processors?
Lynnfield Reaches Retail
Last week Intel's latest addition to its arsenal of desktop processors was released in the form of the Core i7 and Core i5 series' for the LGA1156 socket. These new cores, previously known as Lynnfield (and we will still call it as much throughout our reviews), differ from the previously available Bloomfield processors (only available as Core i7 CPUs for the LGA1366 socket) in a few ways:
- Dual-channel memory controller- Lynnfield does indeed still have an integrated DDR3 memory controller
but here Intel has removed one of the channels from Nehalem to make the
new core dual-channel. While this is theoretically a performance
drawback, in real-world testing (as you will soon see) the third
channel made very little performance difference in most consumer
applications. By removing one channel Intel was able to make the CPU
package smaller (less pins required), lower the cost of ownership (only
two DIMMs needed now) while keeping performance very high.
- No QPI interface- While Nehalem used the QPI interface to communication with the north
bridge of the motherboard, Lynnfield uses a connection called DMI. DMI
is much slower than QPI (2 GB/s versus 26 GB/s or so) but in nearly all
cases that bandwidth will be more than adequate for the amount of data
moving between the processor and chipset even in a worst case
scenario. Again, with this change, Intel was able to lower the pin
count for Lynnfield in relation to Nehalem.
- Integrated PCI Express 2.0- A first for a consumer processor, Lynnfield actually takes 16 lanes
of PCIe 2.0 and moves them onto the die of the processor itself. That
means that the graphics cards (or any other PCIe devices) now
communicate directly with the processor itself rather than through a
north bridge or chipset controller. The advantage here is for a lower
cost chipset though I am betting that performance advantages from this
are going to be minimal to non-existent. This is basically another
move towards a more highly integrated platform on the Intel CPU.
- Split HyperThreading integration- HyperThreading is still around on the Lynnfield processors, but it
will only be enabled on SOME of the product offerings. While the die
size and transistor counts will be exactly the same, Intel will
basically just flip off the HyperThreading capability in order to
create a market differentiation and pricing segmentation. More details
on what CPUs have what on the next page.
- Larger Turbo Mode differentiations- While Lynnfield was being prepared Intel's engineers found out how to
get a little more frequency out of the Nehalem architecture and you'll
notice that when you see the larger Turbo Mode improvements on
Lynnfield. Essentially, the cores have been fine tuned in a way that
will allow them to auto-overclock higher than even the most expensive
Core i7 processors available today.
I won't get into all of the architectural or product differences here, but if you are still a bit behind the curve in that regard you should definitely be checking out the previous Lynnfield launch review in which I go into great detail about all things new and old in the processor, motherboard chipset options, pricing and more.
As with all Lynnfield CPUs, the Core i7-860 runs at just 1.2 GHz when at idle with the EIST features enabled.
This is the maximum speed of the Core i7-860 with Turbo Mode enabled.
These results are basically one stepping (133 MHz) below those of the Core i7-870 processor - a difference made more manageable when you consider the nearly 2x price gap between the two CPUs. In fact, that price point of $285 or so is exactly why our readers demanded we test it in comparison to the Core i7-870 and i5-750...