Its here. A new monster. The newest addition to the Intel processor range, the Core i7, with highly improved memory throughput, 4 logical, and 4 virtual cores. While morphed to socket 1366, the X58 chipset and Triple Channel DDR3, this new generation again means a new architecture with a corresponding leap in performance comparative to the introduction of the Core 2 platform.
One of the more predominant changes is the re-introduction of Hyper-Threading and relocation of the integrated memory controller (IMC) directly into the processor. As a result of those changes the new CPU’s show a notable performance boost in especially multi-threaded applications. Not enough evolution you say? Well, thats not all. No more overclocking with Front Side Bus (FSB), the challenge now is the QuickPath Interconnect solution (QPI). Basically the QPI frequency is the functional replacement of what used to be the FSB, linking the CPU and the Northbridge together. The QPI is a so called point-to-point bus, providing communication between each processor core as well as data transfer to the chipset.
My extreme overclocking preview is based on my experiences at the Overclocking at Intel Nordic 2008 event, where I used the following test setup: Intel Core i7 965 Extreme (Engineering Sample), Intel X58SO “SmackOver” and an ASUS P6T Deluxe, 3×1 GB OCZ DDR3-1600 CL9, a 150 GB Western Digital Raptor X, two ATI Radeon 4870X2’s and a Silverstone Zeus ZM1200 power supply. With regards to cooling I kicked off on air with the Thermalright Ultra 120 Extreme (LGA1366) and got down to business with my Kingpin F1EE.
Enough stone walling, check out what this baby will do. First off, Superpi 1M with the Intel Core i7 965 clocked in at 4.35 GHz and finishing off at 9.6 seconds. For comparison an Intel QX9770 would need an approximate clock speed of around 5 GHz to accomplish a similar result. Note that due to a wrong read out by CPU-Z 1.47, I had to make use of the previous version at that time. I then cranked up the speed on the Core i7 to roughly 4.5 GHz and had a go at Wprime 32M.
By now I had noticed some of the other overclockers were trying to find a maximum stable QPI as well as top speed of the Core i7 965. As Öjvind (Sweclockers) had requested I finish with his P6T, and seeing Nosferatu was still busy with the danish P6T I then went ahead with a newer Intel X58 “SmackOver” (thanks to Thomas from Intel!) and made the following verified speed:
That said, it crashed on me while trying to run Superpi. I usually think there’s always room for improvement and set out to look for the ultimate maximum speed of the Core i7 sample, Thomas had provided me with. Lets just say this next photo took a lot of effort, and sadly, this was not stable enough for booting into Windows, and time was quickly running out for the event itself. Although for an Intel reference X58 motherboard thats still quite impressive!
Last but not least I had a limited time to run some 3D benchmarking with the two Radeon 4870X2, thus only managing a couple of runs with 3DMark Vantage (Performance preset) of around 23.700 points and 25.600 points. Note that the graphics cards were not overclocked at all. As you can tell from four logical cores and added simultaneous multi-threading (SMT), the overall system performance is a lot better with the Core i7. Check out the listing for CPU score in 3DMark Vantage.
In summery I’d note that a multiplier above x29 had a tendency to freeze or even crash the setup, as all of the other teams also experienced. Having said that, it may have been related to that specific batch as Delph1 noted in his article, and there are no indicators to this being an overall issue for the Intel Core i7. I do however have share the feeling that retail samples of the Core i7 965 processors will be more overclockable.
In retrospect, the Overclocking at Intel Nordic 2008 event was a lot of fun. I especially enjoyed meeting some new overclockers (Elmor, MeanMachine, Kinc and the Norwegians), and to be honest I really felt a lot more at ease compared to last year, where the main goal was to try to really push the envelope. Last but not least I’d like to thank Intel Nordic, Thomas and Camilla, for once again giving me the opportunity to enjoy a fantastic overclocking event. And also thanks to Silverstone for sponsoring my Zeus ZM1200 power plant.
Special kudos to Thomas for having gone to extraordinary lengths preparing the event, with 400 litres of liquid nitrogen from AGA Sweden, dream dinners, acquiring all the necessary hardware and giving me the chance to try out two different “SmackOvers”. Only to get pulled out of the shower in the early morning hours to help one big Dane disable the alarm system.