Considering a system overhaul? Here's what this year has to offer...
Whether and when to upgrade your system are always hard decisions to make, especially when there are new platform refreshes due at as-yet-undetermined points in the relatively near future. Commit too early and you can end up paying a premium for hardware that becomes obsolete within weeks, but wait too long and you might discover you've been holding on for a refresh that isn't really worth spending the money on.
Of all hardware options, trying to decide on a new CPU is possibly the hardest decision - and Intel isn't making that any easier this year, with plans to bring new Haswell, Broadwell and Skylake processors to market in a single 12 month period. Even AMD's getting in on the act, though, with its new Carrizo hardware apparently just a matter of weeks away.
Fear not, though, if you're thinking of buying a new CPU now - or if you're planning to do so at any point this year - we have all the information you need to help you decide when to pull the trigger.
Haswell-EX
As a platform, Haswell has been around a while, having had its initial release in 2013. It's no surprise, then, that 2015 has only one scheduled release that goes anywhere near the architecture, and that's the Haswell-EX, a variant of 2014's Haswell-E platform, which is aimed at installation in mission-critical servers. Due to be formalised any day now (maybe even by the time you read this) Haswell-EX is expected to be the most complex CPU ever made by Intel and will push the boundaries in terms of its server platforms.
Released as the Intel Xeon E7 v3, Haswell-EX chips will run in configurations up to eight sockets, integrating as many as 18 cores with hyper-threading and an absolutely huge 45MB of last-level cache. New memory controllers (Jordan Creek 2) will also aim to provide improved performance, though at present it's unclear whether that'll specifically mean support for DDR4 RAM or a faster scalable interface for DDR3.
As with other Haswell chips, the Xeon E7 v3 will use a 22nm tri-gate process with up to 5.56 billion transistors. Notably, it will support the TSX instruction set (Transactional Synchronisation Extensions), which speeds up the execution of multi-threaded software, but was disabled on current Haswell (and early Broadwell) chips because of a bug in the implementation.
Admittedly, none of that's exactly riveting and has little to do with what CPUs you'll find in your home system in the next year or two - though it's interesting that 18-core processing is already technically, if not financially feasible. Nonetheless, Haswell-EX is due to be released in Q2 this year, and will likely be the final iteration of the platform, with successive chips being based on Broadwell-E platform.
Should You Wait?
The short version? No. Not unless you're running a server farm out of your basement. Haswell-EX has some exciting features, but it's definitely not aimed at home users. Even if it were, 2015 is already starting to look pretty crowded for Intel and Haswell's got a lot of competition bringing up the rear, so we'd recommend extreme caution!
Broadwell
Following the 2013 'tock' release of the 22nm Haswell CPUs, 2015 sees the 'tick' release: a 14nm die shrink of the Haswell microarchitecture, with all the benefits that entails. In previous years, that's meant a triple threat of cooler running, lower voltages and around a 10% speed increase at the same price as the previous generation chips, and there's no reason to suggest that will be any different when Haswell replaces Broadwell.
However, one thing that will be different is that Broadwell isn't expected to be a full refresh of the Intel desktop line. Unlike previous tick releases, the low-end chips will be omitted from the update and remain available in their Haswell incarnations until Broadwell's successor is released. This is likely because the Broadwell desktop line has been delayed from its original release, and Intel doesn't appear to be shuffling its successors back to account for that; a decision that has left limited space in its release calendar (not to mention putting strain on consumer buying habits).
It hasn't been officially defined where the cut-off point will be, but the smart money says that Pentium and Celeron chips will not be replaced by Broadwell releases, while Intel Core i3 upwards will - although there's a small chance that the Core i3 will also get skipped. Ultimately, it all depends on what Intel feels are its 'low end' chips.
Broadwell CPUs will only be compatible with Intel 9 Series chipsets (H97 and Z97) so, although it uses the same LGA1150 socket, they will not be compatible with Intel 8 Series motherboards. If you have a Series 8 board, though, there isn't necessarily cause to despair: some manufacturers are able to update motherboard firmware to provide compatibility, so check that out and see whether you're able to upgrade your hardware to add Broadwell support.
The desktop version of the chip - Broadwell-K - is expected to be quad core with a GT3e/lris graphics processing unit on-board. Notably, GT3e has 128MB of its own RAM and supports Direct3D 11.1, OpenGL4.3 and OpenCL 2.0. They benchmark in the range of NVIDIA'S GeForce GT 650M. The TDP of the chips will be in the range of 65 watts, around 20 watts slower than their Haswell equivalents. Although it's already possible to buy mobile version of Broadwell CPUs in retail systems, Broadwell-K is expected to land on shelves late in Q2 2015, probably around May.
Beyond that, Intel will also release Broadwell-E chips that will use the same socket as Haswell-E - LGA2011 v3. You probably won't see these until early 2016, though, and (as with the Haswell-EX earlier) these chips will be marketed under the Xeon name and will be be aimed at high-end systems and servers rather than home use.
Should You Wait?
If you're looking to perform a major upgrade on your system sooner rather than later, and were aiming for a Haswell board and chip, then definitely wait. Broadwell is coming very soon and is likely to provide a far superior option in both financial and performance terms. That said, if you can wait until the end of the year, you might be in luck...
Skylake And Cannonlake
Already previewing, Skylake is the 'tock' release due to follow Broadwell, and is currently expected to launch at the end of 2015. Although this would put it unusually close to the release of the delayed Broadwell, some analysts predict that Intel will seek to maintain momentum by choosing not to push back Broadwell's successors. That said, it's possible that even if mobile Skylake chips are out by the end of the year, it'll be the following year before the desktop versions are ready to sell.
Skylake will be manufactured using a 14nm process before being shrunk to 10nm for the Cannonlake 'tick' release in 2017. Both will use a new socket LGA1151, and be compatible with Intel's new 100 series 'Sunrise Point' chipsets.
Major changes between the Haswell/Broadwell generation of chips and Skylake/Cannonlake include the removal of the FIVR voltage regulator and the integration of the Platform Controller Hub on the CPU die for mobile variants, essentially turning it into a system-on-chip design.
Interestingly, it's expected that Skylake chips will retain backwards compatibility with DDR3 to ease the transition to DDR4, which suggests that 100 series motherboards may come in both DDR3 and DDR4 versions. Mobile platforms will be able to take advantage of the new UniDIMM standard, which is a type of SO-DIMM capable of carrying either DDR3 or DDR4 memory.
Other improvements for the Skylake generation of chips includes PCI-Express 4.0 support (confirmed for Skylake-E only). Thunderbolt 3.0 support, SATA Express support and Iris Pro graphics on all chips as standard. All of the chips will be quad-core, and the Pentium/ Celeron lines will also be updated after missing out on Broadwell replacements. Skylake will also end VGA support, so you'll have to move your monitor to either HDMI or DisplayPort!
Finally, for the mobile platform, Skylake laptops will use a wireless charging technology known as 'Rezence', which all major vendors have pledged to support. Rezence can supply 50 watts at distances of up to 5cm and is activated by a Bluetooth smart link.
Should You Wait?
If you can wait for Skylake, you probably should. It's debatable whether it'll actually make it out this year, but the lack of any confirmation might turn uncertainty about Broadwell into a self-fulfilling prophecy. Unless Intel denies a 2015 release, it might be worth holding off rather than backing a lame horse.
Carrizo
With all the Intel releases going on, it's important not to forget about its rival AMD, which is also releasing a new platform in March. The follow-up to Kaveri, the Carrizo line of chips will include Excavator cores (succeeding Steamroller) and a new generation of Graphics Core Next GPUs.
As part of an attempt to get the drop on Intel, Excavator will support both DDR3 and DDR4 memory controllers, though it's not known at present if both of these will sit on the same die or whether the processor will come in two distinct variants. The platform is also designed using high density libraries normally included on GPUs to reduce the size and power consumption of the die, leading -we're told - to an extremely handy 30% increase in energy efficiency.
Carrizo APUs will use Socket FM2+ and feature four cores, with a TDP of 65 watts. They will also incorporate a Southbridge controller. It's notable that they will be based on a 28nm fabrication process, delaying AMD's predicted shift to 20nm. Despite this, the processor is expected to be the fastest and most efficient APU yet. Indeed, efficiency is a big part of the push for Carrizo's rollout, particularly because it isn't shrinking its die process.
To achieve this, AMD has introduced Voltage Adaptive Operation, which runs the chip at a low average voltage and spikes demand upwards only when necessary - something that wastes less power than constantly shifting up and down.
Carrizo is planned to be compliant with HSA 1.0, which improves graphics performance by sharing resources in parallel and will make it easier to run the chips on non-standard operating systems. A CPU-only variant named Toronto will be made available for server and enterprise markets. Excavator will also be the final iteration of the Bulldozer architecture before it's replaced by Zen (see box-out).
Although Kaveri represented a big improvement for AMD's desktop chips, few would deny that it has underperformed. Many attribute this to AMD releasing the chip during a period of decline for the overall market. It's hope that AMD's focus on the mobile market, with a new one-size-fits-all motherboard for mobile Carrizo devices, will help them regain some market share - but as ever, it's hard to predict the direction things will take.
Should You Wait?
If you're running an AMD system and want to upgrade, then definitely. It's almost upon us, and whatever comes next is going to be so different from Carrizo that there's little chance of salvaging the core components. If you don't update now, it's going to be a long and pointless wait for your next AMD system, which isn't due until late 2016 at the earliest.