It wasn't that long ago that anyone who wanted the fastest system around brought the best of the Intel CPUs. Whether it was the Q8400 or the i7-920, the top of the line Intel was the one we all lusted after and invariably brought. With the release of the Sandy Bridge CPUs this all changed, as there was so much performance to be had from them that what was previously just the price you had to pay for high performance became an expense too far.
The release of the LGA2011 socket, i7-3960X and the X79 chipset had truly staggering performance, yet it was so much more expensive than anything on the LGA1155 socket that we hardly know of anyone that brought one. Even people with money to burn shied away from it. The much vaunted quad-channel RAM actually gave us less bandwidth than the dual-channel P/Zx7 chipsets gave us, and the chipset itself was lacking in features that very quickly appeared on the Sandy/Ivy Bridge range. All in all it was perhaps a step too far for even the most power hungry users.
Intel have never been a company to either rest upon their laurels nor bury their head in the sand and pretend their development direction is perfect when most of us were aware that it wasn't. So rather than continue with something that barely sold, they've revamped their top-of-the-line CPU and re-energised the X79 with a wealth of improvements.
The two big changes that you can tell from the initial specifications table is the boost of the IMC, enabling it to support 1866MHz RAM by default rather than 1600MHz, and also 64GB of RAM without any particular tweaking. We know that the i7-3960 and i7-3930 struggled to run the DDR3 at 2400MHz without enormous fiddling and careful selection of DIMMs, so hopefully this will bring the memory performance up to that of the CPU.
The other major change is a vast increase in the PCI Express 3.0 support and available lanes. Anyone who spends the kind of cash necessary for a humdinging LGA2011 rig are likely to be running multiple GPUs along with RAID and a host of other expansion cards. Having so many PCI Express 3.0 lanes available to us will, in a similar manner to the memory, bring the rest of the system in line with the beastly CPU.
The i7-4960X die has undergone a huge shrink. The Sandy Bridge-E i7-3960X CPU was on a 32nm process and not only measured a fairly whopping 435mm2 but had an barely believable 2.2 billion transistors. The i7-4960X Ivy Bridge-E follows the LGA1155 Ivy Bridge in moving to a 22nm process which has almost halved the die size down to 257mm2 and reduced the number of transistors to a still huge 1.86 billion. Otherwise the design is similar with the L3 cache surrounded by the cores, with the IMC and I/O at the top and bottom respectively.
Support for PCI Express 3.0 comes with a whopping 40 lanes. You could run 2 GTX780s and a monster RAID card without compromising the bandwidth to either of them. If anything it's the chipset that's still slightly disappointing as the USB 2.0 ports and SATA 3Gb/s ports have long since been superseded on the Z87. We know that Intel haven't released a new chipset today so it wont detract from our thoughts on the CPU, but as the i7-4960X is finally up to date it shows how far behind the chipset is, especially for an ultra-high-end product.
As always with a new CPU architecture, or at least a new process and some tweaks, there are a few extra models that have come along with the main model. The i7-4960X is the top of the range, at a pretty hefty $999 which should equate to around the £500 mark. Below that is the version that replaces the excellent 3930K and then there is a quad-core, the i7-4820K. Similarly to the 3960/3930 and, for older readers, the Q6600/Q8400, the middle one is only a multiplier adjustment away and yet around half the price so it should be the one everyone gravitates towards.
For extreme overclockers there is some extra multiplier headroom as well as potential to adjust the BCLK, should you so desire. Alongside real-time overclocking and the reduction to a 22nm process, this should give us a big boost to our overclocks.
Demonstrating that the i7-4960X is a refinement rather than a revolution, Intel expect us to achieve around a 5% improvement over the i7-3960X. Of course that's what we're here to test, so enough with the preamble let's crack on.
Intel Core i7-4960X
ASUS Rampage IV Extreme
Club3D HD7970 Royal Ace
Corsair Dominator Platinum
Corsair Neutron GTX
Windows 7 x64
Our of the box the i7-4960X runs happily at 3.7GHz at a reasonable 1.2v. With the new BCLK overclocking we can, should you desire to overclock that way, reach a very healthy 140MHz on the BCLK. Of course the benefits of clocking the BLCK rather than just using the multiplier and memory dividers are negligible, but it's nice to have the option should you desire it.
Thanks to the 22nm process we can push more volts on the vCore without running into thermal limitations. At 1.4v the i7-4960X is fully stable at 4.5GHz, and with a slight tweak up to 1.424v we can achieve 4.6GHz. Hardly the 4.75GHz we saw from the i7-3960X but by no means a slovenly overclock. The 4.6GHz core speed will be the one we'll use in our testing today.
Anyone who tried to extract high memory speeds from their Core i7-3960X will be glad to see that the improved memory controller on the i7-4960X allow us to not only hit the now common 2400MHz, but for those extreme memory kits you can push on to 2600MHz. We'll stick with 2400MHz for our tests today.
Speaking of tests, let's see how the i7-4960X compares to its predecessor.
A fairly inauspicious start for the i7-4960X. At stock it's very similar to the i7-3930K and i7-3960X, and the overclocked results are extremely similar. There is some improvement in the zLib compression test, but so far it's a fairly standard "faster core speed equals higher results" affair.
Even with the higher available memory clock speed we're not seeing a massive improvement in memory bandwidth. The quad-channel is still 33% slower than the dual-channel LGA1155/LGA1150 offerings, although the i7-4960X is a clear improvement over the i7-3960X.
In pure calculation terms we can see that the refinements have made a difference, in SiSoft Sandra at least. Despite giving away 150MHz to the i7-3960X the Ivy Bridge-E chip comfortably out-performs it in the MultiMedia testing. In the Arithmetic test the results are closer, but you are getting more performance per MegaHertz with the i7-4960X.
A clear demonstration that you should always look at a product as a whole when deciding whether it's worthy of a purchase, we have two very different results in our cryptography tests. In AIDA64 the i7-4960X actually looks pretty underwhelming in the pure AES256 testing. With Sandra, which tests SHA as well as AES it's clear that the newer chip has an advantage. Even at stock there is 500MB/s extra when compared to the regulation i7-3960X.
The extra performance per MHz shows up again in wPrime95. The i7-4960X is 3 tenths of a second faster in the 32M place test at stock, and 2 tenths of a second quicker when overclocked, despite the clock speed being less than its predecessor. In such a demanding test that always produces close results to gain tenths is a mightily impressive achievement.
x264 Benchmark v5
Onto encoding video with the x264 codec and the two chips are nearly inseparable, whether at stock or overclocked. Again the lesser overclock of the new CPU provides equal performance to the i7-3960X that came before.
OpenGL performance has increased massively thanks the extra PCI Express 3.0 lanes that are part of the Ivy Bridge-E CPU. We'd expect them to be equal as we're only running a single GPU, but there is no denying the result. CPU rendering is slightly better on the old chip at stock, but again when they are overclocked the difference is negligible.
Similar to our cryptography test, POV-Ray shows why you shouldn't rely on a single benchmark. Regardless of whether we're at stock speeds or overclocked, the i7-3960X has the better performance. It's only a hairs breadth, but it's there.
In keeping with the results so far, PC Mark gives us a slightly mixed back that ends up being the same. Certainly in Vantage at stock the i7-4960X has the bettering of its older sibling by some margin, even if the gaming result isn't as good. PC Mark 7 stock results are shading towards the Ivy Bridge-E CPU too. With the overclock the memory of the i7-3960X is faster though and it's better in the computation score as well. In the overall PC Mark score though the i7-4960X just has the edge.
PC Mark Vantage
PC Mark 7
3D Mark Vantage
As always in CPU and motherboard tests the 3D results are going to be all-but identical. However, we know that you wont be satisfied if we don't show you the results. Unsurprisingly there is little difference between the two LGA2011 CPUs, although we have to point out how well the overclocked i7-4960X does in the Performance benchmark, despite giving a handful of MHz away to the Sandy Bridge-E CPU.
3D Mark 11
3D Mark 11 has always given us the most uniform results. Whereas Vantage and the latest 3D Mark adjust their results dependant upon a few factors, 3D Mark 11 is consistent to the point of stubbornness. "An extra 1GHz you say, nah I'll do nothing with it".
Despite ending up with a slower overclock, the i7-4960X is consistently better than the i7-3960X it replaces. It's only a handful of points but when you're looking for world record performance those last few points can be vital. It's a similar story with the CPUs at stock with the Ivy Bridge-E improving upon the Sandy Bridge-E in everything but the Fire Strike Extreme test. Even there it's a small difference because you can gain or lose 10 points with each run.
In Unigine Heaven the i7-4960X is consistently a couple of frames per second behind the i7-3960X. We finally have a test in which the clock speed alone dictates the result. Up to now the 4960X has made up its clock speed differential in pure performance.
The two CPUs exchange results in Unigine Valley. The i7-4960X is the most consistent, but the raw horsepower of the i7-3960X cannot be denied.
Resident Evil 6
Away from synthetic benchmarks and on to the gaming of Resident Evil 6 and, just like we saw in 3D Mark 11, it doesn't matter if you're at stock or overclocked, there is nothing between the two CPUs.
With the reduction in die size and shrink from 32nm of the Sandy Bridge-E down to the 22nm of the Ivy Bridge-E there is a massive difference in temperatures at stock. 12°C at idle and 8°C under loading is an enormous improvement. The idle temperature of the overclock is similarly 8°C cooler, although the load temperature is the same because we always overclock as far as we can.
It's not only in thermal output that the i7-4960X is more efficient, as it draws significantly less Watts at the wall when compared to an identical system with the i7-3960X in it. This will save you a fortune in electricity if you have your system on for a reasonable amount of time a day.
As we said at the start, the LGA2011 range so far hasn't been the biggest success Intel have ever had. It's too expensive for the amount of performance that the average user will require. However, if you need extraordinary amounts of power for rendering, or video encoding, or Photoshop work, then the level of power available was too good to be denied.
With the release of the Core i7-4960X have refined the first generation of LGA2011 processors and brought them smack bang up-to-date. The three big improvements have made a big difference.
Firstly the reduction from a 32nm chip as we saw with the Sandy Bridge-E i7-3960X to the 22nm process on the Ivy Bridge-E i7-4960X. This should give us three benefits if past history is anything to go on. Lower power draw is the first, and certainly the i7-4960X is more efficient than the original i7-3960X. This lower power will give us cooler temperatures. At stock this is definitely the case, although overclocked we reach the same maximum temperature. That is largely because we always overclock to the limits, but 8°C cooler out of the box is a massive improvement. Finally the efficiency and lower temperatures should enable us to overclock further. This isn't the case with the i7-4960X. We ended up 150MHz behind the overclock that we achieved on the i7-3960X. However, and this is the important thing, more often than not we're getting equal performance for a slower clock speed than we saw from the SB-E CPU. So whilst the number isn't as impressive, the results still are.
The second big change is the stronger memory controller which supports 64GB and 1866MHz as standard. Of course we all know that Intel's claimed speed isn't a patch on what is obtainable otherwise 2000MHz+ memory kits wouldn't exist. With the i7-3960X we struggled to consistently attain 2400MHz whereas on the i7-4960X it was simplicity itself. Indeed it was so easy that we could overclock our 2400MHz kit to 2600MHz.
The final improvement is one that, on our current test setup, is harder to quantify in our benchmarks, and that's the PCI Express 3.0 as an on-CPU feature, along with 40 PCIe lanes to give you loads of bandwidth. With a single GPU this isn't something that will make a difference, and so it proved in our 3D benchmarks. But if you run a couple or more graphics cards and perhaps a PCIe SSD or RAID card then the benefits of 16/16/8 will certainly be felt. Given that this CPU is designed for the most power-hungry users who are likely to have a system stuffed with the best money can buy, that improvement is likely to make a big difference.
There are a couple of little niggles. Firstly there is no doubt that the i7-4960X is only for the very well-heeled or those who demand the absolute best regardless of cost. For almost everyone a quad-core CPU such as the i7-4770K will provide more than plenty. If you are a Youtube superstar who endlessly renders videos, or a Pixar-wannabe endlessly rendering fur, or just a Photoshop guru with a Wacom welded to your hand, then you can never have enough cores or enough performance. For gamers and surfers and the like, then it's extremely hard to justify the expense. The second is that the big improvements to the i7-4960X coupled with our knowledge of what is achievable on a Z87, really makes the X79 seem a little .. old. Of course that's not a fault of the i7-4960X, just if you buy one you have to put it in something, and a motherboard full of SATA 3Gb/s and USB 2.0 ports is a little behind the times.
So the Intel Core i7-4960X is a refinement of an already hugely powerful processor, now with enough extra features under the hood coupled to lower power and lower temperatures make for a very attractive proposition if you're in the market for a seriously high performance CPU. Of course that price is eye-watering, but the best is rarely a bargain. We're happy to award the Intel Core i7-4960X our OC3D Performance Award.
Thanks to Intel for supplying the i7-4960X for review. Let us know what you think in the OC3D Forums.