A little more than fifteen months after the launch of the Sandy Bridge architecture, Intel has now launched the somewhat delayed new generation of desktop processors, the Ivy Bridges, also designed for socket 1155. These processors have the challenging task of eclipsing the Sandy Bridges, which have been attracting plaudits since their launch in January 2011, in spite of the major delay linked to a bug on the SATA ports of the Intel Series 6 B2 chipsets. Have they managed to do so?
The Tick-Tock strategy
Launching a brand new processor architecture on a new fabrication process is a complex task and can cause serious delays due to the accumulation of problems on each side that can be difficult to locate. With a view to removing uncertainties, Intel has been working with a different development strategy over the last few years.
Every two years, therefore, Intel launches a new processor architecture on a fabrication process that has already proved itself. Thus, at the beginning of 2011, Intel launched Sandy Bridge, manufactured at 32nm on a mature process. This architecture has now been in production for more than a year. This is what’s known as the ‘Tock’. Also, every two years, the alternate years, a new manufacuring process is introduced and combined with the architecture launched the previous year. This is what’s known as the ‘Tick’ and this is what we have this year with the Ivy Bridge processors, engraved at this new 22nm process.
What we have here however isn’t simply a die shrink as we’re moving from 995 million transistors on Sandy Bridge to 1.4 billion on Ivy Bridge. Intel has however changed how it counts transistors. Without giving any more detail, Intel says that Ivy Bridge has 20% more transistors than its predecessor. Die size has gone down from 216 mm2 to 160 mm2.
As you can see on this scale illustration comparing the Sandy Bridge (above) and Ivy Bridge (below) dies, the additional transistors have mainly been added to the GPU. More than just a Tick, Intel is calling this a Tick+. As the integrated graphics part has historically been the weak link in Intel processors, adding transistors here seems, on paper, to make sense.
Ivy Bridge has therefore broadly speaking been designed along the lines of its predecessor, namely:
- Socket LGA 1155, with backwards compatiblility (via a BIOS update) with the motherboards launched in 2011 (P67/H67/Z68)
- A dual channel DDR3 controller as well as a 16-lane PCI Express
- A built-in graphics controller
- Three cache levels, the last (LLC) of which is shared with the graphics core
Several changes have also been made:
- Architectural changes to increase the IPC
- The memory controller officially supports DDR3-1600
- The PCI Express controller is now a Gen 3 type
- The IGP now offers DirectX 11 support and gives higher performance
- Support (under certain conditions) for three screens
At the same time as launching these processors, Intel also launched some new chipsets at the beginning of April, the Series 7s which support USB 3.0 natively. Along with the motherboards, these chipsets also support PCI Express 3.0 though some manufacturers were already marketing previous gen models that were announced as compatible. For more information on this, we refer you to our Z77 motherboard review