Intel Core i7 2600K review

Performance increase doesn’t justify the price premium

YESTERDAY WE TOOK a look at Intel’s Core i5 2500K and today we’re going to take a closer look at the Core i7 2600K which is currently Intel’s flagship processor based on Sandy Bridge. The big feature difference is Hyper Threading support, although the Core i7’s also feature an additional 2MB L3 cache, slightly higher clock speed and a higher turbo frequency for the integrated graphics to set them apart from the Core i5 models.

Editor’s note: Additional Sandy Bridge coverage on it’s way.  Overview, Benchmarks, Linux, Disappointment

So do these extra features justify a $101 price hike over the Core i5 2500K? Well, in one word, no. At least not for the average user, but if you’re once again working with heavy video related work or CPU based rendering of any kind, or you’re just someone that’s looking for the fastest CPU for under $500 out there, then yes, it does offer some tangible benefits over the 2500K. Thanks to Hyper Threading support it’s faster in applications that can take advantage of the extra threads and the 2600K’s are likely to be better bins than the 2500K’s and as such there might be an advantage here for those looking at overclocking their CPU, however so far nothing is indicating that this is the case.

Let’s cut straight to the chase, as we’ve already covered the platform issues in the Core i5 2500K article and the same applies in this case. We did try and overclock the Core i7 2600K and if nothing else, it’s far easier to overclock the K series processors thanks to the unlocked multiplier. Dial in a safe-ish number in the BIOS/UEFI and go from there. We started at 45x multiplier and the system booted happily without any need of tweaking any settings. That means that the CPU went from 3.4GHz to 4.5GHz without the least bit of fiddling around.

So we thought we’d try our luck and go for an even 5GHz. This proved to be far more problematic, but we did get there in the end. The system was stable, but it took a few tries and we had to tweak quite a few settings and up the CPU Voltage to a not very safe 1.5V. This was all done using the Akasa Nero 2 CPU cooler which features a fairly modest three direct contact heatpipes and a 120mm fan. In theory it should be possible to achieve higher results with better cooling, but from what we’ve heard, anything beyond 5GHz is pure luck. Most CPUs so far tend make it to around 4.8GHz though, be it 2600K or 2500K models.

The performance gains at this kind of speed are nothing short of impressive and as an example we managed to cut over 45 seconds of the time it took to transcode our test video compared to the same CPU at stock speed. We also saw an impressive performance gain in Cinebench 11.5, although under heavy load the CPU would throttle back to anything between 4.8 to 4.2GHz during short periods of time, even though we had disabled CPU throttling. This suggests that Intel might have put in a few extra safe guards in the processor to prevent them from overheating.

That brings us to the benchmarks. First up we have Sysmark 2007 and here the gains are fairly small compared to the Core i5 2500K, although there’s something of a performance advantage in the 3D part of the benchmark.

In PCMark Vantage things are looking fairly similar with a very small overall lead for the Core i7 2600K over the Core i5 2500K.

In 3DMark Vantage it’s clear that the extra turbo multipliers of the integrated graphics offer a benefit, but as you can see, manually setting the multiplier on the 2500K yields similar results. With the Sapphire Radeon HD 6870 fitted the 2600K gets a nice little performance boost over the 2500K, but not one that is seemingly worth the extra cost.

In the OpenGL part of Cinebench 11.5 we see a similar scenario using the integrated graphics where the 2600K has a small lead over the 2500K and the same holds true with the discrete graphics card fitted.

In the CPU render test the 2600K offers some real advantages being 1.5 points faster which is a big margin in Cinebench. At 5GHz we’re seeing an improvement of about 2.6 points, which is massive jump in performance and close to that of much more expensive CPUs with more threads. It’s clear that the Sandy Bridge cores are very good at this kind of task and Intel’s old Nehalem architecture doesn’t really stand a chance here clock for clock, core for core.

In POV-Ray things are looking similar with the 2600K cutting about 10 seconds or so off the rendering time. At 5GHz we see another 10 seconds shaved off the time it takes to do the test render.

In Handbrake the extra threads improve the performance, but you’re only gaining about 30 seconds in the case of our transcoding test from AVCHD to MKV.

Arcsoft’s MediaConverter 7 also manages to take advantage of the higher turbo mode of the integrated graphics, but a 10 second win doesn’t seem like it’s worth it when using Intel’s Quick Sync Technology. In CPU rendering mode the time saved is about 25 seconds or so, although at 5GHz the 2600K is as fast as the 2500K is using Quicky Sync Technology which is an impressive result.

Finally we have some power usage figures using the same Intel DH67BL motherboard as we used for the power test of the 2500K. The Core i7 2600K draws a fair bit more power, but this was expected considering the extra threads, higher core clock speed and higher turbo multiplier for the graphics. Still, it never peaked over 110W which must be considered pretty good.

At the end of the day, we can’t say that we’re sold on the Core i7 2600K, as at $317 it’s just not offering enough of a performance advantage over the Core i5 2500K. It’s by no means a bad CPU when it comes to performance; it’s just not as impressive as the Core i5 2500K considering its much higher asking price. There’s still a market for it, but you really want to be using applications that take advantage of the extra threads for it to be a worthwhile upgrade over the Core i5 2500K.S|A

The following two tabs change content below.