Today, in conjunction with the Computex trade show in Taipei, Taiwan, Intel has formally introduced several new desktop processors, all of them geared for enthusiasts who want to overclock their systems. We've known that these products were on the way since Intel called its shot back in March, but we now have confirmation about of a host of details.
All three of the new processors are based on existing Haswell silicon, but they differ in important respects. Here's a look at the specifications of Intel's unlocked CPU offerings, with the three new products in bold.
Two of the new offerings, the Core i7-4790K and Core i5-4690K, were developed under the code name "Devil's Canyon." Like other models with a K suffix, these CPUs are unlocked for easy overclocking. The Devil's Canyon parts differ from other Haswell processors in a few important ways, and Intel claims the changes are intended to improve their overclocking headroom.
The most notable change is a new TIM, or thermal interface material, between the chip and the metal cap (ahem, "heat spreader") protecting it. The TIM on recent Intel desktop CPUs became an issue back when Ivy Bridge was first introduced and the enthusiast community noticed that Ivy's overclocking headroom was often limited by high temperatures. (See Why is Ivy Bridge so hot and bothered?) At the time, several theories were floated to explain why Ivy Bridge didn't fare as well at high speeds as Sandy Bridge before it. One of those involved the switch from a fluxless solder thermal interface to, uh, whatever was used instead. Other possible culprits included the undeniably increased power density of the smaller Ivy Bridge die, which has less surface area for cooler contact, and the frequency-voltage curve of Intel's then-new 22-nm fabrication process. The solder took most of the blame, though, and eventually CPU de-lidding became a thing among overclockers.
Intel hasn't returned to fluxless solder with Devil's Canyon. Instead, it has employed a "next-generation" polymer interface material that's supposed to transfer heat more efficiently. Intel desktop CPU head Lisa Graff told us the polymer TIM was the best option for getting a product to market quickly, since switching to solder would have involved an interruption in manufacturing. (And you never stop a fab at Intel if you want to keep your job.) I suspect the polymer TIM may also be cheaper than solder, but that's just speculation.
Another change meant to improve clock frequency headroom in Devil's Canyon is the addition of more capacitors on the underside of the CPU package. Intel says the added caps will "smooth power delivery to [the] die." One more change, which seems relatively minor, is a new max power rating of 88W for the Devil's Canyon parts.
Although it seems like a minor tweak, the higher TDP probably helped enable what may be the most notable performance gain in Intel desktop CPUs in years: the Core i7-4790K will ship with a base clock speed of 4GHz and a single-core Turbo peak of 4.4GHz. Both speeds are 500MHz faster than the prior top-end Haswell, the Core i7-4770K. And the 4790K will sell for the same price as the 4770K when it arrives. The 4670K, by contrast, will only be 100MHz faster than the prior fastest Core i5.
Despite the tweaks to the package and TIM, Devil's Canyon processors will be compatible with the same sockets and coolers as current Haswell-based desktop CPUs. Intel's guidance for a while has emphasized that Devil's Canyon products will be compatible with motherboards based on its new 9-series chipsets. Now, the firm tell us that folks should check with their motherboard makers about compatibility with 8-series motherboards, as well. Apparently the 4W TDP change may cause problems for some boards, but honestly, I'd expect the majority of enthusiast-class mobos to be able to handle Devil's Canyon processors after a firmware update.
We don't yet know how much additional headroom Intel has managed to squeeze out of Haswell with the tweaks to Devil's Canyon, because we don't yet have one to test. Intel has evidently hit a few snags in getting the products ready to roll. By way of explanation, Graff told us that the schedule for Devil's Canyon is uncharacteristically aggressive, asserting that a product of this sort would have traditionally launched in September, not June. That said, the official launch window for Devil's Canyon parts is still "June 2014," so we remain hopeful the schedule won't slip further.
For a lot of folks, the other new CPU from Intel may be even more exciting. The Pentium G3258 is an Anniversary Edition model, created to help mark the 20th anniversary of the Pentium name. This little Haswell costs only $72 and has an unlocked multiplier. The 3.2GHz base clock and paltry 53W TDP rating pretty much scream "overclocking potential."
If the frequency headroom is decent on these, I expect we could see a rash of budget gaming builds based on them. Although newer games often take advantage of four cores or threads pretty well, per-thread performance is kinda like displacement in American car engines: there's no replacement for it. Two fast Haswell cores could anchor a really sweet gaming rig. Sadly, though, the Pentium G3258 isn't a Devil's Canyon part, so folks may wind up de-lidding them in order to exploit their full potential.
Intel says the G3258 should work with both 8- and 9-series motherboards. Like other recent Pentiums, its QuickSync video transcoding block is enabled. The Anniversary Edition Pentiums are also slated to go on sale in June, so we'll be watching for their arrival at online retailers.