Intel Core i7-3770K review

Intel’s new Ivy Bridge processors are finally here. You may have hear of Intel’s Tick-Tock strategy, where a Tick is a new, smaller production process and Tock is a major architecture change, and the Ivy Bridge range is officially a Tick – it has a new 22nm process, compared to Sandy Bridge’s 32nm, but its core processor architecture hasn’t changed. However, the new processors do have a significantly improved graphics architecture, which promises more speed in games as well as faster GPU-assisted video encoding with Intel’s QuickSync technology. Because of this Intel is describing Ivy Bridge as a ‘Tick+’.

Compared to Sandy Bridge, the new processors have a smaller 22nm process for lower power consumption and a smaller TDP

COMPATIBILITY

Intel has kept the same Core i5 and Core i7 branding – but with Ivy Bridge labelled as “3rd Generation Intel Core” – which could be confusing. Far more perplexing, though, are the compatibility issues. The good news is that Ivy Bridge uses the same LGA1155 socket as the previous generation. There is a new range of 7-series motherboard chipsets designed to be used with the new processors (Z77, Z75 and H77), but the processors will also work on the H61, H67, P67 and Z68 motherboards – with one caveat.

The older chipsets will need to be updated to support Intel’s new ME8 Management Engine, which is apparently more complicated than a simple BIOS update and will need to be done by the manufacturer. Intel recommends you get confirmation from the manufacturer that a motherboard will support Ivy Bridge before you buy, or just get a board with a 7-series chipset.

The die shrink means the processors will run cooler – they have a 77W TDP, down from Sandy Bridge’s 95W. This lower heat output means the chips can Turbo Boost for longer, which should lead to better performance in desktop tasks than on Sandy Bridge, despite the same core architecture. This theory was borne out by our test chip’s performance in our 2D application benchmarks. Intel sent us the Core i7-3770K to test, which is a 3.5GHz quad-core chip with Hyper-Threading, so appears as eight processors in Windows. The processor can Turbo Boost up to 3.9GHz for added performance, but for how long depends on how cool it is kept.

Graphics hardware now takes up a larger proportion of the chip’s surface

To see how much application performance had improved, we compared the Ivy Bridge processor to a previous-generation Sandy Bridge chip. The processor’s Sandy Bridge equivalent is the Core i7-2700K, which also runs at 3.5GHz with a Turbo Boost up to 3.9GHz. We only had an Intel Core i7-2600K available for testing, which runs at 3.4GHz with a 3.8GHz Turbo Boost, so we raised its Turbo Boost headroom to 3.9GHz to make it largely equivalent – this is only a 2.5% overclock.

APPLICATION BENCHMARKS

The Ivy Bridge processor was much faster in our benchmarks – which are normalised to a Core i5-2500K scoring 100. In our video-encoding test we saw a score of 154 from the i7-3770K, compared to 103 from the i7-2600K. In our multitasking test, the Ivy Bridge chip managed 126, while we saw 114 from the Sandy Bridge model. This led to overall scores of 132 from the i7-3770K, compared to 112 from the overclocked i7-2600K – the new chip is around 15% faster in our benchmarks.

This seems to be because the chip’s lower heat output means it can maintain a Turbo Boost speed for longer; we kept an eye on CPU-Z’s processor speed monitor during our benchmarks, and found that the Ivy Bridge processor stayed at maximum Turbo Boost for the entire benchmark suite, while the Sandy Bridge processor had to throttle back to its normal speed a quarter of the way through. In both cases we only used Intel’s stock cooler. Even when we disabled all but one core on both processors, the Ivy Bridge chip managed 35 overall compared to 30 from the Sandy Bridge processor, showing the new chip to be around 15% faster core for core in real-world tasks.