Intel i7-4960X Ivy Bridge-E Review

 Author: Saravanan & Karthi
 Date: September 23, 2013

 Product Name: i7-4960X

In the world of high end processors, Intel’s Extreme editions have always been at the enthusiast market’s forefront. From Gulftown to Sandy Bridge E, the last few generations have gradually moved the yardsticks forward with better performance and increased instructions per clock. Now, Intel’s Ivy Bridge Extreme is looking to pick up the mantle from its predecessors by introducing Intel’s flagship CPUs to a 22nm 3D Tri gate manufacturing process.

While the mainstream product segment has moved on to the Haswell microarchitecture alongside Z87 motherboards, the extreme family has been lagging behind in some respects. The outgoing SB-E processors have been around for nearly two years now which may not seem like a long time but that’s an eternity in the world of processor lifespans.

Some have blamed this stately progression on the near-complete lack of viable competition from AMD while those with a mind towards conspiracy theories tend to point a finger at Intel purposely holding back technologies from the high end in order to milk their current offerings for all they’re worth. The actual reasoning behind this out-of-sync approach likely isn’t quite so dramatic.

Like its predecessor, the Ivy Bridge Extreme processors are based on Intel’s Xeon E-series server / workstation CPUs, though in this case the IVB-EP architecture is being used. As we have seen in every processor generation, the extreme and EP series progression marches to the beat of a different drummer while still maintaining Intel’s valued Tick / Tock strategy. So, it shouldn’t come as any surprise that these new processors are being released after Haswell made its debut not that long ago.

Since Ivy Bridge is essentially a 22nm die-shrink of Sandy Bridge, there really aren’t many base architectural differences. The memory controller is integrated onto the die, as it has been for the last few generations while the Queue, Uncore and primary I/O functions haven’t experienced any major changes in the move away from Sandy Bridge. The memory controller has been slightly revised with official support for DDR3-1866 memory but for enthusiasts that isn’t much of a change since Sandy Bridge-E CPUs had no problem reaching that frequency anyways. In addition, all processors now have native support for PCI-E 3.0.

The move to 22nm Tri-Gate 3D transistor technology is a particularly important one for these large 265mm² CPU dies. It essentially stacks transistors across the die’s z-axis in order to save room and increase processing efficiency which has significant effect upon power consumption and heat output. In most instances, these new processors will consume less power, allowing system builders some additional PSU overhead.

Since the Tri-Gate 3D technology essentially stacks the processor’s hottest-running elements across a more concentrated area, Ivy Bridge processors typically run hotter than their predecessor but Intel has revised their IHS design in an effort to alleviate this issue.

While the standard desktop Ivy Bridge variants retained four physical cores and up to eight threads, the Extreme die ups the ante with six cores and 15MB of L3 cache that‘s shared between the processor cores and other architectural functions. Unfortunately, for the time being, we won’t see any eight, ten or twelve core desktop CPUs (with up to 24 threads) as those have been reserved for the Ivy Bridge EP lineup.

Much like the move between the mainstream desktop versions of Sandy Bridge and Ivy Bridge, these new Ivy Bridge Exreme processors represent a simple incremental performance increase over Sandy Bridge-E. The focus for IVB-E has been put squarely upon moderate IPC boosts and some serious on-die efficiency improvements. Sadly, this means the actual performance difference between it and comparable processors from the SB-E era will be minimal in most instances.

Headlining Intel’s new product stack is the i7-4960X, a 6-core, 12-thread fully unlocked processor that has nearly the same specifications as the outgoing i7-3970X and one-ups the older i7-3960X by a significant margin. There is a small 100MHz Base Clock increase and a lower TDP but everything else remains the same, even the stratospheric $999 price point.

Moving slightly further down the lineup we have the i7-4930K and i7-4820K which replace the i7-3930K and i7-3820 respectively. Both of these look like worthy replacements for their forefathers for a number of different reasons. The i7-4930K still features twelve threads and a TDP of 130W but makes due with slightly less L3 cache than its $450 more expensive sibling while operating at frequencies that equal the i7-3960X. That represents an impressive speed boost over the 3930K. TDP remains at 130W but with less L3 cache, expect power needs to be further reduced.

In our opinion, the most interesting processor in this lineup is the i7-4820K due to the limitations of the processor it replaces. While the i7-3820 had its multiplier capped at 45X, this new CPU has a max multi of 63X so hitting ultra high frequencies won’t require changes to the Base Clock or gear ratio (two items which could hold back overclocks in some instances). The 4820K also features the highest Base Clock of any IVB-E processor and represents a very good competitor to the slightly more expensive Haswell i7-4770K. This could quickly become the darling of Intel’s Ivy Bridge Extreme lineup.

So with all of this information being thrown into a melting pot, what does IVB-E offer over SB-E on the performance front? Not all that much but enough to keep it relevant in today’s marketplace. Games and general tasks won’t be accomplished with noticeably more speed but Ivy Bridge’s IPC improvements will translate into improved speed within processing-intensive environments.

In many ways, these new processors aren’t meant as an upgrade path for Sandy Bridge-E users even though they are a simple drop-in upgrade for X79 motherboards (a BIOS update may be necessary though). The addition of official PCI-E 3.0 support and more overclocking features on lower-end SKUs will certainly be tempting but it is Gulftown, Bloomfield and AMD Thuban users who should really be paying attention here. For them, the performance increases and expanded feature set will likely be worthwhile.